How to propagate Taxus cuspidata? Detailed explanation of cutting propagation techniques
Taxus is a precious greening tree species in China, its leaves are evergreen all year round, and its wood is excellent timber, with very good planting prospects. Below, the editor will tell you about the cutting propagation techniques of Taxus cuspidata, hoping to be helpful to growers.
Taxus is a precious greening tree species in China, its leaves are evergreen all year round, and its wood is excellent timber, with very good planting prospects. Below, the editor will tell you about the cutting propagation techniques of Taxus cuspidata, hoping to be helpful to growers.
1 Seed propagation techniques
1.1 Seed collection
The seeds of Taxus cuspidata generally mature from late September to early October, and need to be collected promptly after maturity. During the seed maturation period, select robust, pest-free mature mother trees, collect the seeds, wash and rub off the red aril on the surface with water, rinse clean, soak them, and store them in moist sand. The after-ripening period of Taxus cuspidata seeds is relatively long, with double dormancy characteristics, and they need to go through two winters and one summer before they can germinate.
1.2 Site selection and land preparation
Taxus cuspidata likes moisture but fears waterlogging, prefers cool shade, and is extremely shade-tolerant, with an inconspicuous main root and well-developed lateral roots. Therefore, generally choose plots with loose, fertile soil and convenient drainage and irrigation, or it can also be planted under Korean pine forests or mixed coniferous-broadleaf forests with low planting density. After selecting the seedling site, plow it, with a plowing depth of 30-35 cm being appropriate. Then apply base fertilizer, mainly decomposed agricultural organic fertilizer, with an application rate of about 1,000 kg/667 m2, and after fertilizing, rake the land level.
1.3 Seed treatment
About half a year before sowing, soak the seeds in 0.5% potassium permanganate solution for 40 min, then rinse with clean water 2-3 times, remove and mix evenly with fine sand at a ratio of 1:3. First spread the seed bag flat on moist sand, then cover with a layer of moist sand and bury it with soil. Fifteen days before sowing in the second spring, take out the seeds and spread them in a sunny, sheltered place to dry, turning them frequently. Two days before sowing, soak the seeds in 500 mg/L gibberellin for 24 h, take them out and rinse with clean water 2-3 times, and then they can be sown.
1.4 Sowing
Taxus cuspidata is generally sown in drills or broadcast. The sowing time is generally in early May. Before sowing, water first to make the soil thoroughly wet. For broadcast sowing, sow directly, then cover with about 1 cm of soil and lightly compact. For drill sowing, first open furrows about 5 cm wide and 2-3 cm deep, with a distance of about 20 cm between furrows, scatter the seeds in the furrows, and then cover with soil.
1.5 Seedling stage management
After the seedlings emerge completely, they need to be watered promptly. After rain, loosen the soil and weed promptly to ensure the soil is loose. When the seedlings grow to 2-3 leaves, thin them promptly. In the first year of sowing, generally fertilize 2-3 times, mainly with nitrogen fertilizer and potassium fertilizer, applied as foliar spray. After the seedlings grow for 2-3 years, they can be lifted from the nursery and planted out.
2 Cutting propagation techniques
2.1 Collection and treatment of cuttings
Around mid-March, select healthy, pest-free, middle-aged superior varieties as mother plants to collect cuttings[2]. The cuttings are generally new shoots within one year of growth, with a collected length of 10-15 cm. After collection, the cuttings should be stored at low temperature, preferably -5-5 °C, and their bases should be covered with 60% moist sand to retain moisture and shield them from sunlight.
2.2 Cutting time
Cutting at the right time can greatly increase the survival rate of Taxus. When the deep soil temperature is above 10 °C and the greenhouse indoor temperature is stable above 15 °C, it is conducive to promoting cell division at the cut and rooting and surviving as soon as possible. Therefore, the cutting time can be determined according to the local temperature changes of that year.
2.3 Cutting bed preparation
The cutting bed can be prepared about 7 days before cutting. The cutting bed is generally 1-1.2 m wide and about 20 cm high, and the length is determined according to the actual length of the plot. First spread a layer of decomposed farm organic fertilizer at the bottom of the cutting bed as base fertilizer. To reduce the occurrence of pests and diseases, a certain amount of dexon or carbofuran can be added to the base fertilizer, and then on top of the base fertilizer spread an 8-10 cm thick cutting substrate mixed from decomposed sawdust, garden soil, and fine river sand at a ratio of 3:2:1.
2.4 Cutting
First cut off the leaves about 5 cm from the base of the cuttings, then cut off 1-1.5 cm from the lower cut to promote rooting, and retain the terminal bud. Soak the cuttings in rooting powder solution and then they can be inserted. When cutting, first make holes with a pointed wooden stick, with a hole depth of 4-5 cm, and the plant and row spacing of the cuttings is about 10 cm x 10 cm. After cutting, press the soil around the roots firmly and water.
2.5 Management after cutting
On the one hand, keep the temperature in the greenhouse at 15-25 °C; on the other hand, maintain sufficient ventilation and air humidity above 80%. If the temperature is high, spray appropriately to cool and retain moisture; if the temperature is low, appropriately reduce the ventilation time. Pull out weeds promptly when they grow. Generally after about 1.5-2 months, they can root and survive. If managed properly, the survival rate can reach 80%-90%.
After survival, they can generally be transplanted and planted out after growing in the nursery for about 2 years. In the second year after survival, the warming facilities need to be removed, and topdressing should be carried out according to their growth to cultivate strong seedlings.
Taxus has two propagation techniques: it can be propagated by seed or by cuttings. According to the editor's understanding, Taxus combines ornamental, medicinal, and economic value, and is currently planted in many regions of China. If you want to plant greening seedlings, you can consider planting Taxus. The above are its propagation techniques, which you can refer to.
Taxus Taxus chinensis (Pilger) Rehd. Taxus illustrated guide: how to grow Taxus / how to propagate Taxus
Taxus profileTaxus Taxus chinensis (Pilger) Rehd.
Cultivation methods and precautions of Taxus Introduction to Taxus
Taxus, also known as yew, is a plant of the genus Taxus. Taxus is a shallow-rooted plant, with an inconspicuous main root and well-developed lateral roots. It is internationally recognized as a rare natural anti-cancer plant on the verge of extinction. It is an ancient relict tree species left over from the Quaternary glaciation, with a history of 2.5 million years on Earth. Because under natural conditions Taxus grows slowly and has poor regeneration ability, for a long time no large-scale Taxus raw material forest base has been formed worldwide. In 1994, Taxus was designated by China as a first-class rare and endangered protected plant, and at the same time it is called a "national treasure" by 42 countries around the world that have Taxus. The United Nations has also explicitly banned its felling, making it a veritable "plant panda."
Taxus is an evergreen tree, with alternate branchlets that turn yellow-green or light reddish-brown in autumn; winter bud scales are rounded on the back or have blunt ridges; sickle-shaped leaves, in two rows, 1.5-3 cm long, broader than other species of the genus Taxus, with pointed and slender tips, and two yellow bands on the underside of the leaves; flowers axillary, dioecious, female flowers with only one ovule, subtended by several scales; flat oval seeds, each side with an inconspicuous ridge, surrounded by a red cup-shaped aril.
Morphological characteristics of Taxus
Taxus is an evergreen tree, up to 30 m tall, with a diameter at breast height of 65-100 cm; bark grayish-brown, reddish-brown, or dark brown, splitting into strips and falling off; large branches spreading, one-year-old branches green or pale yellow-green, turning green-yellow or light reddish-brown in autumn, two- and three-year-old branches yellow-brown, light reddish-brown, or gray-brown; winter buds yellow-brown, light brown, or reddish-brown, glossy, winter bud scales rounded on the back or with blunt ridges; leaves linear, dioecious, seeds flat and round.
Taxus has an inconspicuous main root and well-developed lateral roots. Leaves spirally alternate, twisted at the base into two rows, linear and slightly curved, 1-2.5 cm long, 2-2.5 mm wide, leaf margins slightly recurved, leaf tips acuminate, with 2 broad yellow-green or gray-green stomatal bands on the underside, densely covered with small raised dots on the midrib, the green band at the leaf margin extremely narrow, dioecious, male cones solitary in leaf axils, ovules of female cones solitary at the top of short lateral axes on the upper part of the flower axis, with a disc-shaped aril at the base. Seeds flat ovoid, with 2 ridges, seed ovoid, aril cup-shaped, red.
Taxus branchlets alternate, branches flat or slanting, densely grown, with persistent bud scales at the base of branchlets; one-year-old branchlets green, light reddish-brown after autumn, two- to three-year-old branches reddish-brown or yellow-brown. Winter buds pale yellow-brown, bud scale tips acuminate, with longitudinal ridges on the back. Leaves spirally arranged, arranged in irregular 2 rows, V-shaped and slanting, 1-2.5 (3.5) cm long, 2-3 cm wide, straight, rarely slightly curved, apex usually mucronate, base narrow, with a short petiole, dark green and glossy above, midrib raised, with two gray-brown stomatal bands below, stomatal bands twice as wide as the green margin. Dioecious, cones solitary in leaf axils. Seeds ovoid, purplish-red, borne in a red fleshy cup-shaped or urn-shaped aril, about 6 mm long, 5 mm in diameter, upper part with 3-4 blunt ridges, apex with a small blunt tip, hilum triangular or nearly square, rarely broadly elliptic.
Taxus flowers from May to June, seeds mature from September to October, and the seeds are used for oil extraction and can also be used as medicine.
Ecological habits of Taxus
Taxus is suitable for planting in both northern and southern parts of China, with characteristics of shade preference, drought tolerance, and cold resistance, and requires soil pH of 5.5-7.0.
Taxus prefers a cool and humid climate, can withstand low temperatures below minus 30 °C, has strong cold resistance, with an optimum temperature of 20-25 °C, and is a shade-loving tree species. It is shade-tolerant in habitat and can also grow under dense forests; it is perennial and does not form forests. It is mostly found in mixed coniferous-broadleaf forests dominated by Korean pine. It likes moisture but fears waterlogging, and is suitable for planting on loose, moist, well-drained sandy loam.
Taxus mostly grows on rocky or barren soil on mountain tops, mostly in shrub form. In its place of origin, the annual average temperature is 2 °C to 7 °C, and the annual average precipitation is 750-1,000 mm. It is mostly scattered under moist, fertile mixed coniferous-broadleaf forests on shady or semi-shady slopes.
Taxus is suitable for planting in both northern and southern regions. It has the characteristics of shade preference, drought tolerance, and cold resistance, and requires soil pH of 5.5-7.0. It can be interplanted with other tree species or orchards, and is simple to manage. Among them, Taxus cuspidata is an ancient tree species left over from the Quaternary glaciation. Under harsh climatic conditions, its tenacious vitality has enabled it to live on Earth for more than 2.5 million years. It not only has well-developed lateral roots, luxuriant branches and leaves, and strong sprouting ability, but also adapts to a wide range of climates, has broad soil requirements, and is also tolerant of pruning, cold, and pests and diseases.
Cultivation techniques of Taxus Seedling management
Temperature regulation
After inserting the cuttings, the bed surface ground temperature should be maintained at 18 °C-25 °C, the temperature in the shed at 22 °C-28 °C, and the soil moisture at 60%-70%.
Seedling stage management
Observe the temperature and humidity in the plastic shed every day. When there are water droplets inside the plastic film of the arched shed, it is not short of water; when there are no water droplets, it is short of water. When short of water, uncover the plastic film to receive rain appropriately or water. When the temperature in the shed reaches 30 °C, promptly open the plastic at both ends of the arched shed for ventilation. After sunset, seal the plastic film tightly again to maintain the temperature in the shed. Before snowfall, remove the upper shading net and move it under the plastic in the arched shed to continue shading and prevent direct sunlight on the seedlings. About 45 days after cutting, the cuttings begin to root, and after about 65 days they are basically fully rooted. In the same year, they can grow 3-5 cm tender branches. After 2 years, they can be transplanted, and at this time the root system is relatively well developed and easy to survive. When they grow to 6-8 years, the saplings are 80-90 cm tall.
Weeding and disease prevention
Weeding should be carried out when the grass has just grown. If the grass is large and its roots are strong, it may accidentally be pulled out together with the seedlings, or air leakage may cause the seedlings to die, so weed early and frequently to avoid loss of water and fertilizer. In the rainy season, Taxus seedlings are prone to root rot and stem rot. At this time, 70% dexon 400-700 times solution can be sprayed and irrigated. In dry and high-temperature seasons, seedlings are prone to leaf blight, and 1% Bordeaux mixture can be sprayed for control.
Tissue culture
Tissue culture utilizes the totipotency and clonability of plant cells. Using the young stems, needles, bark, cambium, aril, embryos, etc. of Taxus plants as explants for culture research.
1. Select superior Taxus varieties as explants, inoculate them into culture medium, and through steps such as callus formation, rooting, and seedling bud cluster formation, a large number of tissue-cultured seedlings can be obtained in the laboratory. After substrate transplanting, hardening, inspection, and quarantine, they become production seedlings.
2. The ratio of early to late callus formation in Taxus differs among different species and among different plants of the same species. At the same time, it is related to factors such as explant type, sampling site and collection season, light conditions, and culture medium type.
Potted maintenance
1. For newly purchased Taxus bonsai, when new buds have just sprouted, try not to spray fertilizer solution on the leaf surface, because at this time the Taxus bonsai has not truly survived or the leaves are too tender. If fertilized at this time, the tender leaves or buds will shrink and curl. This will affect the normal sprouting of new roots. Do not spray too much clean water on the leaf surface; the degree should be that water droplets can be seen on the leaf surface but do not drip down. Spray two hours before dark in the afternoon, and do not leave water droplets at night (even less so when the amount is larger), otherwise it will affect the normal growth of tender leaves or cause the leaves to turn yellow, affecting the healthy growth of the plant. (The underside of the leaves can be sprayed more than the upper side, because the upper side of the leaves has a waxy protective film that hinders the absorption of nutrients and water, while the underside of the leaves has no waxy layer, has more stomata, and has a stronger ability to absorb water and fertilizer. Therefore, the underside absorbs faster and more than the leaf surface.) Depending on the situation and temperature, once a day or two to three times a day. Note that the room needs frequent ventilation.
2. For newly purchased Taxus bonsai, because part of the root system is damaged when transplanted from the planting base into the flowerpot, the nutrient supply between the roots and the branches and leaves becomes imbalanced. Especially for those bonsai with luxuriant branches and leaves, the transpiration of the leaves is greater than the absorption of the root system. When the potting soil remains moist, the top leaves curl and dry up. At this time, it is best to prune the branches and leaves appropriately to reduce excessive consumption of water and nutrients by the branches and leaves and help the root system recover growth as soon as possible. At the same time, control watering and keep the potting soil slightly dry to facilitate the rapid growth of fibrous roots and speed up the restoration of normal nutrient supply. At the same time, Taxus has a strong sprouting ability, especially strong new branch growth ability, and is very tolerant of pruning. After survival, it will soon sprout new branches and new leaves. When necessary, plant rooting or root-increasing agents can be used to water the potting soil about once every seven days, for three to four consecutive times (use a better-quality product and do not use too much water at the same time) so that the root system can grow quickly and healthily. This helps restore the supply balance between roots and leaves as soon as possible and enables Taxus to grow well.
3. Because the nutrients in a potted Taxus bonsai are limited, they can only provide about half a year of growth needs, or the current plant shape is relatively large and consumes a lot of nutrients, so consumers are advised to replace the original pot as soon as possible after purchase. Because our company carries out a re-potting period of more than one month for the bonsai, and it is stored for a period of time at the distributor, and Taxus likes fertile and loose soil. It is best to change the pot as soon as possible. When changing the pot, based on the inner diameter of the flowerpot, the inner diameter of the new pot should be at least 5 cm larger. Do this before new buds sprout in February or March each year, and when the potting soil is neither dry nor wet, pour the tree and potting soil out together. Try not to break the original soil ball. If after survival too many roots are found, the bad roots can be appropriately cut off. Place the tree into the new pot, fill nutrient soil around it, and press lightly to firm it. Only when the soil in the pot is in close contact with the roots can the survival rate be improved; otherwise, the plant is not easy to survive or grow vigorously. However, do not press the soil too firmly. If it is too firm, the roots cannot breathe air, which will cause root rot and plant death. After planting, water thoroughly immediately. Place the pot in a cool place for a few days. After watering, the potting soil should not be turned or pressed again, otherwise the potting soil is prone to compaction, or the soil is too firm and poorly ventilated, which can easily cause root rot.
4. Fertilization methods for Taxus bonsai: the three major elements of plant growth are nitrogen, phosphorus, and potassium fertilizers. Nitrogen fertilizer can promote the growth of flowers, grass, branches, and leaves; phosphorus fertilizer can promote the formation of flowers and fruits; potassium fertilizer can promote the growth of stems and roots.
Because the bonsai is cultivated in the limited space of the pot and in limited cultivation soil, organic matter is decomposed by bacteria into inorganic salts and absorbed by the roots. With the consumption of Taxus growth, the nutrients in the potting soil gradually become insufficient, resulting in an inability to supply growth needs. Although prepared nutrient soil is used in the bonsai, do not fertilize within three months after purchase. Just water with about 1,000 times potassium dihydrogen phosphate solution or spray it on the leaves every seven to ten days in the evening. Control the amount of watering and do not water too much. Only when the leaf color becomes lighter, the plant becomes thin and weak, the leaves are yellow-white, "dry-burnt edges" appear at the leaf edges and tips, and the leaves age prematurely and fall off, apply 1,000 times urea solution, 800 times potassium sulfate quick-dissolving high-quality compound fertilizer solution after removing sediment to the potting soil, about once a month. It is best to use fully decomposed dilute soybean cake fertilizer water (about 10%-15%), avoiding the trunk when applying, and applying as much as possible along the pot wall, once every half month. On the second day after fertilizing, water again with clean water to dilute it in case the applied fertilizer is too concentrated. The above two fertilizers can be used alternately, or two small holes can be dug in each pot and five or six granules of urea and seven or eight granules of high-quality compound fertilizer placed inside. Then cover with soil and water to dissolve the fertilizer. Taxus bonsai should avoid raw fertilizer and concentrated fertilizer. Topdressing should mainly be nitrogen and phosphorus fertilizer, and must not be too concentrated.
5. Watering methods for bonsai: the principle is "do not water if not dry, water thoroughly when watering"
Water is an important component of the flower and tree body. All life activities of flowers and trees must be carried out with the participation of water. Whether photosynthesis or transpiration, water is indispensable. Water can maintain cell turgor pressure and keep branches and leaves upright. However, exceeding the limit will instead make the plant grow thin and weak. If there is too much water in the potting soil for a long time, it will cause the leaves to turn yellow, fall off, root rot, and even death.
1. If the surface color of the potting soil becomes slightly lighter and the leaves are slightly curled, and when pressed with a finger the potting soil feels somewhat soft, and when lightly tapped with a finger joint on the upper middle part of the pot body the sound is relatively dull, then the potting soil does not need watering; just spray the leaf surface to supplement the water in the leaves. When the soil surface turns white, and when pressed with a finger the soil feels relatively hard, and a ring of cracks appears between the pot and the soil, and when lightly tapped with a finger joint on the upper middle part of the pot body it makes a crisp "bang bang" sound, and new shoots and young leaves wilt, then the potting soil should be watered. Before watering, the cracks between the soil and the pot should be pressed firm with a hard object, then water with a large spoon. When pouring, the spoon should be close to the pot rim, pour the water in at once, and water thoroughly in one go so that the potting soil absorbs enough water. If a small amount of water is poured into the pot and after a while water is seen flowing out quickly from the bottom of the pot, it means the soil and pot are not completely pressed firm, and an object should be used to press tight the gap between the pot wall and the soil before watering. When the potting soil structure is normal, it is better if after watering the water slowly seeps out from the bottom of the pot in about 40 seconds to one minute. The water temperature for watering must be close to or consistent with the temperature at that time. When using tap water, first place the water in sunlight for about three hours before watering, because light helps decompose oxides in tap water and can raise the water temperature. The water can also be placed in a large basin for half a day or one night before watering. If there are many bonsai, it is best to put the water in a large vat so that the water temperature is as close as possible to the air temperature and soil temperature. Especially in hot seasons, in addition to watering the potting soil, water mist should also be sprayed on the leaf surface to keep the leaves moist, which is beneficial to growth. The potting soil can be kept slightly dry and must not be too wet. When there are many pots, be sure to check each pot according to the actual situation, taking care not to miss watering or overwater.
2. Taxus leaves are evergreen all year round and are suitable for placement indoors. However, Taxus bonsai should not be placed at the air outlet of an air conditioner, otherwise it will increase the evaporation of water from Taxus leaves and easily cause the branches and leaves of Taxus to dehydrate quickly, causing the leaves to curl and dry up. If placed in an air-conditioned room and the air conditioner is turned on every day, spray the leaf surface every day to maintain leaf humidity, and place a basin of clean water indoors. If in a heated room in northern winter, it should be placed farther from the radiator, and a basin of clean water should be placed on the radiator to increase indoor air humidity. In summer and autumn, when the temperature exceeds 30 °C, shading and cooling work should be strengthened, and it can be moved to a ventilated room facing north. When necessary, spray water to cool down, creating a cool and humid environment to facilitate the growth of Taxus. Also avoid rooms where direct west-facing sunlight shines directly on the Taxus bonsai. In winter, the amount of watering of the bonsai should be controlled to avoid long-term excessive moisture in the potting soil. Because in winter the plant grows weakly and the leaves volatilize less water, if the potting soil is too wet for a long time, the surface of the potting soil will become compacted and impermeable, which can easily cause root rot in the plant. When growing Taxus indoors, be sure to pay attention to frequent indoor ventilation.
3. The soil for planting Taxus should preferably be loose, rich in humus, fertile, and slightly acidic soil (PH=5.5-7). Do not pour leftover tea water into the Taxus bonsai. If leftover tea water is often poured in, because the tea contains theophylline and other raw alkalies, it will change the soil pH and also have a relatively destructive effect on organic nutrients in the soil. It inhibits the growth of Taxus and also causes excessive soil moisture, hindering ventilation of the potting soil and causing root rot and stem rot. If conditions permit, about once a week in the evening move the Taxus bonsai to the balcony to receive dew, and in the morning place it in sunlight for about one to two hours to receive light (before ten o'clock in the morning), which is beneficial to the growth of Taxus and improves disease resistance. In summer and autumn, prevent direct west-facing sunlight from shining through the window onto the Taxus, to prevent high temperatures from scorching the leaves and affecting ornamental value.
6. Key points to note
1. Because Taxus is small, attention should be paid to regulating light. It needs light but should not be placed in strong light for too long. Generally, in summer and autumn, two hours of sunlight before ten o'clock in the morning or after five o'clock each day is enough. At ordinary times, receive more scattered sunlight. Otherwise, strong light will scorch the leaves and cause the leaf tips to turn scorched yellow. Also maintain indoor ventilation so that the plant does not develop poor growth phenomena such as wilting and drooping due to overly dry indoor air.
2. If a new bonsai shows dull yellow, lusterless tender leaves and wilting at the top center of new shoots, it is generally caused by too frequent and excessive watering, compacted and impermeable soil, and partial root rot, resulting in weakened water and fertilizer absorption capacity. For mild symptoms, control the amount of watering, use a hard and blunt object to gently loosen the surface soil of the pot to make the potting soil breathable, move it at night to a place where it can receive dew, and move it to a cool place at eight or nine in the morning, which is conducive to the healthy recovery and growth of the root system. If the leaves turn yellow and curl within a short period, it indicates severe root rot, and the pot should be turned immediately to check the root rot condition, (normal fibrous roots are tender, plump, and white in shape). If more than half are affected, it generally cannot be saved.
3. Old leaves turning yellow from bottom to top, but new leaves generally growing normally, is generally caused by not watering thoroughly in one go, with too little water causing root water shortage. Sometimes the top leaves dry up and curl, and dry leaves fall off when touched, but the old leaves grow normally, which is generally also caused by root water shortage, and the plant should be watered thoroughly in one go. When watering, be sure to first press firm the cracks at the pot rim with an object to prevent water from quickly leaking out through the cracks after watering. This creates the false appearance of thorough watering, and over time it will cause the roots to die of water shortage and the trunk to die. At night, move it outdoors to receive more rain and dew, and receive two hours of sunlight in the morning and evening to help Taxus recover its growth.
4. Taxus is suitable for weakly acidic soil. If irrigated with alkaline water for a long time, it will cause the leaves to turn from green to yellow, and even fall off. Therefore, add acidic nutrients or spray the leaves or water the potting soil with a 0.2% ferrous sulfate solution, once every ten days, for three consecutive times. This can make leaves yellowed by alkalinity turn green again.
5. Every year in March and April, Taxus will sprout a large number of tender buds, which will consume a large amount of nutrients. At this time, the tender buds growing toward the inside can be removed to prevent the branches from being too dense and unventilated, which would cause the leaves to turn yellow or fall off. Thin and prune crossing branches, inward-facing branches, and leggy branches, which can improve ventilation and light penetration, and can save excessive consumption of water and nutrients. When the tender buds have just sprouted, it is best not to spray liquid fertilizer on the leaf surface, or apply concentrated fertilizer at the roots.
6. For normal fertilization amount, if using urea alone as nitrogen topdressing, the concentration is generally 0.1%; if using potassium dihydrogen phosphate alone as phosphorus topdressing, the concentration used is 0.1% to 0.2%, with an interval of seven to ten days between topdressings.
Afforestation
Selection of afforestation site
Lower and middle parts of hillsides, slope feet, Cao gullies, shady slopes of mountain bays with a slope of less than 35 degrees, soil pH 4.5-7.0, and plots with high fertility, moisture, and good drainage can all be used as afforestation sites. Artificial young forests with a canopy density not greater than 0.4 can also be used for afforestation.
Land preparation
Strip or hole land preparation. The hole specification is 40 cm x 40 cm x 30 cm (length x width x height). Under different land conditions, manure can be applied in combination with land preparation according to soil fertility.
Afforestation density
1,100/mu. Plant and row spacing 60 x 400 cm (across the mountain x along the mountain). When afforesting in artificial young forests, the density should be determined according to the actual canopy closure of the young forest. The principle is to plant in open spaces with good light conditions outside the crowns of young trees.
Afforestation time
Spring February-April, autumn September-November.
Management and operation
After afforestation, tending should be carried out 2-3 times each year. Hoe tending twice in May-June and August-September, and knife tending in July. Starting from the second year after afforestation, combine hoe tending with topdressing every May. Starting from the fourth year after afforestation, raw materials can be harvested each year by pruning branches and leaves, or the whole plant can be dug out (including the root system) for extracting taxol. For greening, prune according to the required shape.
Cultivation methods of Taxus Seedling management and lifting for afforestation
1. Seedling overwintering management: seedlings are afraid of frost. In winter, they must be protected with an arched shed for warmth, and it is best to add a straw curtain over the plastic film.
2. Seedling transplanting and hardening: after seed-grown seedlings or cutting seedlings are cultivated for 1 year, they should all be transplanted and hardened. Transplant the seedlings into open-field seedling beds at a plant and row spacing of 25-30 cm, build a 1.5 m high shade shed with six shade and four sun, water frequently, and when the seedlings fade yellow, apply dilute urea water or light manure water to cultivate strong seedlings.
3. Lifting for afforestation: Taxus seedlings hardened for 1 year can be lifted for afforestation when the seedling height is 40-60 cm. Planting is best in late winter and early spring, with a planting plant and row spacing of 1.6 m x 2 m.
Maintenance habits
Distribution area: mainly produced in Shaanxi, Sichuan, Yunnan, Guizhou, Hubei, Gansu, Hunan, Guangxi, and other places
Environmental distribution: cold alpine limestone mountainous areas
Ecological habits: shallow-rooted plant
Life form: evergreen tree
Sunlight: shade-loving
Moisture: drought-tolerant
Temperature: optimum temperature 20-25 °C
Soil: sandy loam
Altitude: up to 1,000-1,200 m above sea level
Edible value: leaves and fruit peel can be processed into tea
Medicinal value: diuresis and reducing swelling
Industrial value: purification of taxol, wood carving
Special uses: greening and ornamentation
Toxicity: toxic
Symbolic meaning: longevity
General plant height: about 30 m tall
Propagation methods of Taxus Seed propagation
Taxus is mostly propagated by seed. After the seeds mature in November, they can be harvested. Then clean the fleshy seed coat and dry it, and immediately stratify and bury it in moist sand in a shady, dry place, covering it with plastic film and a straw curtain. In summer and autumn, turn the seeds twice a month, and by early March of the following year, they can be sown for seedling cultivation. The seedbed should be selected as a slightly acidic sandy loam plot that is sheltered from wind and has good drainage, with a bed width of 1 m, a ditch width of 40 cm, and high ridges running east-west. On both sides of the ridge, bury 25 cm high, 4 cm thick steel plates, 10 cm deep. The bed soil should be deeply plowed and finely cultivated, and carbofuran should be applied to control underground pests. Use vermiculite, river sand, peat, and garden soil in equal parts, and add fungicides such as carbendazim or thiophanate-methyl, mix into a substrate and fill it into the steel plates, level with the side plates and 3-5 cm higher in the middle. Cover with plastic film and seal for fumigation for 3 to 5 days, then sow.
Scatter the seeds evenly on the bed surface, with a sowing rate of about 200 seeds per square meter. After sowing, press flat slightly with a wooden board, cover with 1 to 2 cm of mixed substrate soil, and cover with a straw curtain or plastic film to retain warmth and moisture. In dry weather, spray water appropriately. Generally after 40 days, they can germinate and emerge. At this time, remove the plastic film or straw curtain, and build a 2 m high shade shed above the seedbed, covering it with a shade net to prevent direct sunlight. Keep the seedbed moist. On rainy days, build a low arched shed and cover with plastic film to prevent excessive moisture in the seedbed. Do a good job in drainage and ventilation of the seedbed, and promptly prevent and control pests and diseases. During the seedling stage, apply decomposed dilute cake fertilizer water once every 10 days, and avoid chemical fertilizers and concentrated fertilizers. After one year of careful maintenance and management, the seedlings can reach 15-25 cm in height and have 2-3 forked branches. Transplanting can be carried out in early April. The planting site should be selected as a wind-sheltered, dry, humus-rich, slightly acidic sandy loam site, plowed 20 cm deep, and apply 5 kg of decomposed organic fertilizer per square meter. Make high ridges, dig deep ditches, ridge width 100 cm, ditch width 30 cm. Plant 5 rows per ridge, with a row spacing of 20 cm and a plant spacing of 15 cm.
Transplanting should preferably be chosen on cloudy days, and should be planted as it is moved, with a soil ball required for transplanting. After transplanting, water thoroughly immediately, and build a 2 m high shade shed above it, covering with a shade net on sunny days, and removing it on cloudy and rainy days and at night. During the growing period, strengthen fertilizer and water management, generally applying decomposed cake fertilizer water once every 10 days. Do a good job in pest and disease control management. In summer, strengthen shading and cooling work, and when necessary spray water to cool down, so as to create a cool and humid environment conducive to seedling growth. Taxus is not only a superior material for making high-grade furniture, but also a medicinal material with great medical value, and moreover an excellent tree species for landscaping. With the maturity and development of its artificial propagation and artificial cultivation techniques, the application scope of Taxus will become even broader.
When propagating seedlings with Taxus seeds, pay attention to the storage method of the seeds. They should be stored mixed with sand or treated with temperature control, which has a very good effect on sprouting after overwintering and breaking dormancy habits. Before sowing, rub and damage the seed coat, soak the seeds in warm water, and treat with chemicals and hormones. Shading after emergence is the key to seedling cultivation. It can prevent high-temperature scorching of seedlings and maintain moisture, with a suitable light transmittance of 40%. The emergence rates of Taxus cuspidata and Taxus wallichiana var. mairei can both reach 70%-80%, and the required emergence temperature is above 15 °C.
The dynamic growth of seed-grown seedlings is as follows: the plant height and stem thickness of seed-grown seedlings grow slowly in the first two years after emergence, with plant height generally increasing by about 10 cm per year, and growth accelerating after one year of transplanting. From 3-5 years, the annual increase can reach 20-30 cm.
Key points of seed propagation
1. Collect seeds: harvest red fruits from September to October, rub off the red aril and flesh, wash clean, and store mixed with moist sand.
2. Damage the seed coat: the after-ripening period of the seeds is relatively long, with dormancy characteristics. Under natural conditions, they need to go through two winters and one summer before they can germinate, that is, placed outdoors for freezing in winter, receiving high temperature and rain in summer, and sown in autumn of the following year. If sown in spring, they can remain frozen in outdoor soil after winter, then be moved into a warm room in late March to early April for germination acceleration before sowing, and can emerge more than 20 days after sowing. If the seeds can be repeatedly rubbed with coarse sand using the sole of a shoe on rough cement ground, wearing through their inconspicuous tough seed coat and thinning their hard seed shell (do not rub the kernel to pieces), the seeds can easily absorb water and air, and germinate faster after sowing.
3. Variable temperature treatment: Taxus seeds have dual dormancy habits of radicle and hypocotyl. The radicle needs to go through a high-temperature stage above 25 °C for about 1 month to break dormancy, and the hypocotyl needs about 1 month at minus 3 °C to minus 20 °C to release dormancy. In order to accelerate seed germination earlier, as long as the Taxus seeds with damaged seed coats are mixed with moist sand and placed in an environment below minus 3 °C for freezing for 25-40 days, their hypocotyl dormancy can be released. After sowing in late winter or early spring, after about 2 months, when encountering temperatures above 25 °C, the radicle dormancy can be broken, and the seeds can sprout and emerge.
4. Sowing and seedling cultivation: drill sowing. After emergence, shading is required. Seedlings are afraid of sunscald. The light transmittance of the shade shed should be 15%-20%, and weeding should be frequent. Water with dilute urea water or clean manure water once every 15-20 days to promote seedling growth. After 1 year, they can be transplanted in the open field.
Cutting propagation
For cutting propagation of Taxus, softwood cuttings are better in spring, and hardwood cuttings are better in autumn. Generally, low-shed shading treatment is required during cutting. Generally, the cutting survival rate can reach more than 70%. Conventional cuttings, however, are only about 3%-20%. The shading rate should not be less than 60%. The base of the cuttings should undergo careful rooting treatment. Humidity should initially be maintained intermittently at about 75%-85%. Avoid strong winds causing water loss.
Factors affecting the cutting survival rate generally include: tree age, temperature, chemical treatment concentration, substrate, season, humidity, variety, and other human factors.
In the first year of rooting, the aboveground part of the cutting seedlings grows slowly, but rooting is rapid and lateral roots are well developed. After transplanting in the second year, further shading treatment and seedbed management are needed. Ensure corresponding environmental conditions, and growth accelerates. Growth is fastest in summer, and slow in winter and spring. At this time, attention should be paid to temperature changes; long-term dryness can cause growth inhibition or sudden death. However, after the seedlings are strengthened in the seedbed, the afforestation survival rate of Taxus is very high. There is very little death, and growth is rapid.
Key points of cutting propagation
1. Collecting cuttings: In May to June at the transition between spring and summer, cut current-year young shoots from mother trees aged 4 years or older to use as cuttings.
2. Cutting treatment: Cut branches more than 15 cm long to use as cuttings, remove the lower leaves, and girdle the base of the branch to create a wound of 0.5-1 cm. After tumor-like tissue forms around the wound, cut the branch off below the girdle, and soak the basal end in 100 ppm indoleacetic acid or phenylacetic acid for 3 hours, or soak in 200 ppm ABT No. 2 rooting powder solution for 8-10 hours.
3. Cutting method: Insert the treated cuttings into a prepared seedbed or a medium of vermiculite plus weathered sand (1:1) with sawdust. The insertion depth is 3-5 cm, with a plant and row spacing of 8-10 cm. After insertion, water thoroughly and cover with a plastic film arch to retain moisture. At first, spray water 2 times a day, and after 2 weeks, once a day. Shade as for seed propagation. Roots form 45-50 days after insertion. With careful management, the seedling survival rate can reach more than 90%.
Disease control of Taxus
Taxus stem rot is one of the most serious diseases affecting Taxus cuttings during the growing period.
About 2 months after cuttings are taken, stem rot occurs successively at the base of the stem of the cuttings (where the underground and aboveground parts of the cutting meet). It starts with a few individual plants becoming diseased and then spreads to affect the entire cluster, causing the leaves on the cuttings to lose green color, die, and drop. Because this disease mainly occurs in the hot summer and autumn seasons, the damage to the cuttings from high soil temperature creates conditions for pathogen invasion. The occurrence and spread of the disease mainly depend on the temperature in July to August. If the disease occurs early and the seedlings have weak heat resistance, the disease is more severe.
Control measures
1. Reduce the surface soil temperature of the seedbed during summer and autumn to prevent scorching the base of the seedling stems and avoid creating wounds that allow pathogen invasion;
2. Increase fertilizer application to promote the growth of the cuttings and enhance their disease resistance.
3. Use quintozene powder + dexon powder mixed in water at a concentration of 5 g/kg for irrigation, which gives the best control effect of up to 89%, or use carbendazim + thiophanate-methyl wettable powder mixed in water at a concentration of 4 g/kg for irrigation, which gives a control effect of 83%.
4. For large-scale control of this disease, alternating the above 2 methods can basically control the occurrence of stem rot in cuttings.
Taxus variety classification and related species
Complete list of 11 Taxus species worldwide
1. Taxus cuspidata
Taxus cuspidata, also called purple yew or red cypress pine, is one of China's 4 species and 1 variety of Taxus. The others are: Taxus wallichiana var. yunnanensis, Taxus wallichiana, Taxus chinensis, and Taxus wallichiana var. mairei.
It is mainly distributed in the temperate coniferous and broad-leaved mixed forest regions of Northeast China, Japan, Korea, Russia, and elsewhere.
Tree
The tree can reach 20 m tall, with a trunk diameter of up to 1 m. The crown is obovate or broadly ovate. The bark is reddish brown or grayish red, thin, and splitting into flakes. The branches are densely borne; the twigs are reddish brown, and the current-year branches are dark green, turning light reddish brown after autumn. The leaves on the main branches are arranged spirally, while those on the lateral branches twist at the leaf base and are arranged in two irregular rows to the left and right. The leaves are linear, nearly straight or slightly curved, 1.5-2.5 cm long and 2.5 mm wide, dark green and glossy on the surface. It is dioecious. The cones are borne in the leaf axils of the previous year's branches. The male cones have 9-14 stamens, and the female cones have one ovule. The ovule is ovate, pale red, and erect. The seeds are ovate, purplish brown and glossy when mature, about 6 mm long and 5 mm in diameter. They are covered by an aril that is open at the upper part, obovate, cup-shaped, deep red, fleshy, and rich in juice when mature. The flowering period is May to June, and the seeds mature in September to October.
Characteristics
It is shade-tolerant in habitat and can also grow under dense forest. It is long-lived but difficult to form pure stands. It is mostly found in coniferous and broad-leaved mixed forests dominated by Korean pine. It can withstand low temperatures below minus 30°C and has strong cold resistance. Its optimum temperature is 20°C to 25°C. It likes moisture but fears waterlogging, and is suitable for planting in loose, moist, well-drained, airy loam.
The plant height of Taxus cuspidata grows slowly in the first-year seedling stage, grows faster one year after transplanting, and seedlings over 3 years old can increase in height by 20-30 cm each year. A characteristic of Taxus cuspidata is that the small branches of the tree turn yellow-green or light reddish brown once autumn arrives. Its leaves are arranged in two rows, slightly curved and sickle-shaped, looking like a ball up close and like a flower from a distance, very ornamental. Seedlings like shade and need shade management in the first year after transplanting.
Uses
The stems, branches, leaves, and roots are used as medicine. The main components include taxol, taxine, and diterpenoid compounds. It has anticancer functions and also has effects in inhibiting diabetes and treating heart disease. According to identification by authoritative departments and related reports, Taxus within China all contain a certain amount of taxol, and especially the bark of Taxus cuspidata, which grows in a special environment, has the highest content, reaching up to 5 per ten thousand. The unique climatic conditions are conducive to the deposition of substances in the plant. If Taxus cuspidata is appropriately moved southward, it can increase the growth period, improve the growing environment, help the synthesis of active ingredients in the plant, and increase content and quality.
Landscaping
Taxus cuspidata is not only a rare medicinal plant but also an excellent choice for landscaping and courtyard beautification. It is currently the most precious and rare high-grade landscaping tree species. Its unique bonsai ornamental value is another major feature of Taxus cuspidata. Taxus cuspidata bonsai has a simple and elegant shape, with compact but not crowded branches and leaves, spreading but not loose. Its red stems, red branches, green leaves, and red fruits give it multiple ornamental values for viewing stems, branches, leaves, and fruits. The smooth red stems represent openness and nobility, the evergreen needles express firmness and eternity, and the red fruits, much like "love beans," highlight affection and longing. The overall shape is restrained without being exposed, extraordinary and refined, with a strong flavor of life and cultural richness. Because of its scarce resources, Taxus cuspidata is listed as a first-class rare tree species in China for protection.
2. American yew
American yew, English name American yew, is one species of Taxus. Taxus is also called purple yew or red cypress pine, with the alias beautiful yew. It is an evergreen conifer. There are 9-11 species worldwide, and 5 species in China. Because the differences in appearance are not great, the species are mainly divided by region. The main varieties include Taxus cuspidata, Taxus wallichiana var. yunnanensis, Taxus media, Taxus mairei, Taxus chinensis, Taxus wallichiana, Taxus baccata, Taxus brevifolia, Pacific yew, and American yew. Usually, Taxus trees are evergreen trees or shrubs, with twigs irregularly alternate. The leaves are linear, spirally arranged, more or less twisted at the base into 2 rows or overlapping irregular 2 rows, straight or sickle-shaped, with the midrib raised on the upper surface and two grayish green or pale yellow stomatal bands on the lower surface, and the petiole has no resin canals. It is dioecious. The cones are solitary in the leaf axils and have short stalks. The male cones are globose, with imbricate bracts at the base, 6-14 stamens, peltate, anthers 4-9, radially arranged. The female cones are almost sessile, with many imbricate bracts at the base, the ovule erect, subtended at the base by a disc-shaped aril. After fertilization, the aril develops into a fleshy, cup-shaped, red aril. The seeds are nut-like, ovate or oblong, with a pointed tip, borne in the cup-shaped fleshy aril.
American yew is monoecious, unlike common Taxus. It is a shrub 2 m tall, monoecious, relatively short, usually branched and layered. The bark is pale red and very thin. The branches are spreading and upward. The leaves are 10-25 mm long and 1-2.4 mm wide, pale green, mostly lacking surface papillae along the stomatal bands, ranging from dark green to yellow-green. In cross-section, the leaf epidermal cells are wider than tall or about ± isodiametric. The seeds are somewhat flattened, 4-5 mm. x=12. In the picture, peculiar red fruits the size of cherries can be seen, with the seeds borne in the cup-shaped fleshy aril.
Taxus wood is fine and dense, bright red in color, tough and durable. Taxus contains the anticancer drug taxol, and Taxus media is the preferred tree species for extracting taxol. Taxus is a very good ornamental tree species and can also be made into high-grade bonsai. American yew is often planted as an ornamental plant along roadsides and around homes. Countries around the world explicitly prohibit the felling of Taxus. The attached photo was taken beside a road in a residential area of Mississauga, Canada.
3. Taxus chinensis
Aliases: purple yew, red cypress pine, Guanyin yew, etc.
There are 11 species of Taxus worldwide, distributed in temperate to tropical regions of the Northern Hemisphere. China has 4 native species and 1 variety, namely Taxus chinensis, Taxus cuspidata, Taxus wallichiana var. yunnanensis, Taxus wallichiana, and Taxus wallichiana var. mairei (variety). Among introduced species is Taxus media, introduced to China from Canada in the mid-1990s, and now cultivated in Sichuan, Ziyuan and Lingui in Guangxi, Shandong, and other places.
Taxus chinensis is one of the species of Taxus. Taxus (scientific name Taxus mairei) is a relict plant from the Quaternary Ice Age and a rare and endangered species in the world. Taxus chinensis is endemic to China and is distributed in southern Gansu, southern Shaanxi, western Hubei, Sichuan, and other places. In the central China region it is mostly found in undisturbed environments on upper mountain slopes above 1000 m, while in the southern and southwestern regions it is mostly found in deciduous broad-leaved forests on mountains at 1500-3000 m. It is relatively concentrated in the Hengduan Mountains and the mountains around the Sichuan Basin, and is also distributed in northern Guangxi, eastern Guizhou, and southern Hunan.
China lists it as a first-class key protected plant.
Morphological characteristics
Evergreen tree, up to 30 m tall, trunk diameter up to 1 m. Leaves spiral, twisted at the base into two rows, linear. Slightly curved, 1-2.5 cm long, 2-2.5 mm wide, leaf margin slightly recurved, leaf tip acuminate, with 2 broad yellow-green or gray-green stomatal bands on the back, densely covered with small raised dots on the midrib, green marginal band extremely narrow. Dioecious, male cones solitary in leaf axils; ovule of female cone solitary at the apex of the lateral short axis on the upper part of the floral axis, with a disc-shaped aril at the base. Seeds flattened ovate, with 2 ridges, hilum ovate, with a red cup-shaped aril, maturing from September to November.
Biological characteristics
It prefers to grow in places with a relatively warm and rainy climate, and is a typical shade-tolerant tree species. It is often found in the second and third tree layers under the forest canopy, scattered, basically with no pure stands and rarely in clumps. It grows well only on well-drained acidic gray-brown soil, yellow soil, and yellow-brown soil. Seedlings like shade and avoid sun. Its seed coat is thick and the seeds are in deep dormancy. Under natural conditions, they germinate only after two winters and one summer, and natural regeneration ability is weak. Propagated by seeds. The embryo dormancy period is relatively long. After seed collection, the seeds must be stored in wet sand stratification at low temperature, sown in spring, and the germination period may be extended to the second year. It can also be propagated by cuttings.
Economic uses
Although Taxus chinensis is relatively widely distributed in China, its resource reserves are small. It is mainly used for medicine, ornamental purposes, and scientific research.
1. Medicinal uses
Taxol and its derivatives extracted from the plant body of Taxus chinensis are among the best anticancer drugs in the world today and have very high development and utilization value.
In 1971, the United States extracted taxol from Taxus. Because the extract of Taxus (TAXOL PACLI TAXEL) taxol has a unique anticancer mechanism, Dr. BRODER, director of the National Cancer Institute of the United States, called taxol, after doxorubicin and cisplatin, a new anticancer drug considered over the past fifteen years to have good efficacy against multiple cancers and few side effects. Beginning in the 1980s, the United States, the United Kingdom, Russia, South Korea, and China all carried out in-depth research one after another. The U.S. Food and Drug Administration (FDA) approved it for clinical use in 1992. The United States took the lead in applying research results to medical clinical practice and achieved remarkable clinical results in treating various cancers. It has been proven effective against multiple cancers, especially with successful treatment of ovarian cancer and breast cancer, with a cure rate of 33% and an effective rate of 75%. Taxol has become the world's recognized best drug for treating cancer. Since then, humanity has made another breakthrough in the field of anticancer treatment. Therefore, up to now and for a considerable period in the future, the most advantageous weapon for humanity in fighting cancer can only be taxol. The world's annual production of taxol is only about 250 kg, and market supply and demand are unbalanced. The price is extremely expensive, up to more than 200,000 US dollars per kilogram, so Taxus is known as "plant gold."
Taxol is mainly extracted from the roots, bark, stems, and leaves of Taxus. Because the extraction process is relatively complex, especially in removing the chlorophyll component from the original liquid, and because equipment investment is relatively large, especially with a lack of raw material sources, large-scale extraction of taxol developed relatively late in China, just beginning in the 1990s. Because under natural conditions Taxus grows slowly and has poor regeneration ability, for a long time no large-scale Taxus raw material forest base had been formed worldwide.
2. Ornamental uses
Taxus chinensis has a beautiful and elegant tree shape and is evergreen through the four seasons. When the fruits mature, the color combination of red and green is intoxicating. It can be widely used in soil and water conservation,
horticultural ornamentation, and other aspects. It is an excellent tree species for improving the ecological environment and building beautiful mountains and rivers in the new century, and is now often used for high-grade courtyard landscaping and ornamentation.
3. Scientific research uses
Taxus chinensis is a rare and endangered plant left over after the Quaternary glaciation, with very few natural distributions worldwide, and is listed as a national first-class key protected plant. It has extremely high scientific research value in many aspects.
4. Other uses
Taxus chinensis wood is fine and dense, bright red in color, tough and durable, and is a precious timber tree species. It is often used for carving, making high-grade furniture, handicrafts, and so on; the wood is rot-resistant and can be used as timber for civil engineering; the seeds have an oil content of 60%, with special development value.
4. Taxus wallichiana var. yunnanensis
Other common names: purple yew, sacred tree
National Class I key protected wild plant (approved by the State Council on August 4, 1999)
Taxus wallichiana var. yunnanensis is one of China's 4 species of Taxus. It is a tall evergreen tree with luxuriant branches and leaves and strong vitality. A single tree can live for more than a thousand years, and it is praised as a "sacred tree" by local ethnic minorities. A Taxus tree in Luobu Township, Weixin County, Yunnan, is 72 m tall, 202 cm in trunk diameter, and already 800 years old. It generally can reach 30 m tall. It is dioecious, with a fruiting period from October to November. The fruit is bean-like and has a red aril.
Taxus wallichiana var. yunnanensis is a local endemic species centered in Yunnan. It is mainly distributed in Baoshan City and Tengchong County in western Yunnan, and in the Zhongdian, Lijiang, and Weixi areas of northwestern Yunnan. It often grows on subtropical mountains at an altitude of 2000-3500 m. Its habitat is on shaded slopes, semi-shaded slopes, mid-mountain and subalpine gentle slopes, valleys, and both banks of streams in dark coniferous forests, mid-mountain coniferous and broad-leaved mixed forests, and evergreen broad-leaved forests, growing scattered or in patches, often becoming lower-layer trees.
Taxus wallichiana var. yunnanensis is a precious tree species at the provincial level in Yunnan and also a first-class key protected tree species in Yunnan Province. The bark contains taxol, harringtonine, and other components. In recent years, scientists have found that related components of Taxus are effective drugs for treating multiple cancers; Taxus is also a traditional Chinese medicinal material. Its seeds are used as medicine, the seeds contain starch and sugar, and the aril is edible.
Taxus wallichiana var. yunnanensis is the main tree species in China for producing taxol drugs. Based on many years of measured data on the content of taxol and the semi-synthetic raw material baccatin (including 10-deacetylbaccatin III and baccatin III) in Yunnan yew forest tree samples, and comparing them with other Taxus species, it is shown that Taxus wallichiana var. yunnanensis is a tree species with high content of the above 3 active components. In natural forests of Taxus wallichiana var. yunnanensis in Yunnan, the taxol content in bark is about 0.02%, with a maximum of 0.0304%. The average taxol content in small branches and leaves is 0.0102%, with a maximum of 0.0217%. The total baccatin content can reach 0.0808% (bark) and 0.0845% (branches and leaves), all with excellent industrial utilization value. In planted Yunnan yew forests, the content of medicinal components does not decrease significantly. In the root system of planted forests, samples with high taxol content of 0.0421%-0.0460% and baccatin content of 0.103% have appeared, all reaching the high content levels of taxol and baccatin in the world-famous taxol raw material tree species Taxus media (hybrid) and Taxus baccata. Among samples, the differences in the 3 active components are very large, reaching several times to 17 times. There may be 3 reasons: (1) genetic differences among trees; (2) influence of the ecological environment; (3) differences in sample preparation, storage, and analytical determination. Research and improvement in these 3 aspects are expected to increase the content of medicinal active components in Taxus wallichiana var. yunnanensis.
Taxus wallichiana var. yunnanensis has excellent timber, which can be used for construction, furniture, utensils, and so on, and its extract taxol has anticancer effects. It is a precious tree species integrating timber, medicine, and landscaping. In particular, its taxol content is far higher than that of other Taxus species. Taxus has strong adaptability to the environment and is an excellent economic tree species for improving the ecological environment and building beautiful mountains and rivers in the new century. At the same time, it also has very broad development prospects in landscaping and indoor bonsai, and its boards can be exported. Experts predict that this tree will sell well for a long time and have extremely high benefits. It is suitable for cultivation in places with suitable conditions throughout China, and its development prospects are very broad.
5. Taxus wallichiana var. mairei
Aliases: beautiful yew, red Torreya, purple yew
Family and genus: Taxaceae, Taxus
Protection level: National Class I key protected wild plant (approved by the State Council on August 4, 1999)
Origin and distribution: Produced south of the Yangtze River basin in China, often growing in mountain forests below 1000-1200 m altitude, scattered. In Guiyang City it is mainly distributed in Huaxi, Wudang, Kaiyang, and Xifeng. In Anhui Province it is mainly distributed in Shimen Township, She County, Huangshan City, and the Huangshan District area. It is also widely distributed in the Baishanzu National Nature Reserve in Zhejiang Province, with the largest concentration from Sandui Village, Qingyuan Scenic Village, to the Jingning area.
Morphological characteristics
Evergreen tree. Leaves spirally arranged, in two rows, linear, slightly curved or nearly sickle-shaped, 1-3 cm long, 2.5-3.5 cm wide (in sprouts or seedlings longer, up to 4 cm, and up to 5 mm wide), apex acuminate, midrib raised on the upper surface, with evenly arranged papillae on the midrib band, or completely without papillae, with two yellow-green stomatal bands on the lower surface, margin often not recurved, green marginal band relatively wide. Dioecious, cones solitary in leaf axils; ovule of female cone solitary at the apex of the lateral short axis on the upper part of the floral axis, subtended at the base by a disc-shaped aril. Seeds obovate, slightly flattened, apex slightly with two longitudinal ridges, borne in a red fleshy cup-shaped aril.
Taxus is an evergreen tree, about 20 m tall, with a trunk diameter of 60-100 mm. Twigs alternate, leaves spirally arranged, in two rows, linear, slightly curved, 1-4.5 cm long, 2-5 mm wide. Fruit a spherical nut, aril, seed ovate. Dioecious, cross-pollinated. Flowering period March to June, fruiting period September to November. Scattered in mountain forests at an altitude of 500-3500 m. It likes shady, moist, and cool climates, with an average annual temperature generally of 11.2°C and annual precipitation of about 487.9 mm.
Habitat and ecological characteristics
Taxus wallichiana var. mairei is one of the endemic components of China's subtropical to warm temperate zones and is often found in broad-leaved forests. It prefers to grow in
relatively moist places in the hinterland at the foot of mountains. It has relatively strong adaptability to climate, with an average annual temperature of 11-16°C and a minimum extreme value reaching -11°C. It is strongly shade-tolerant and moisture-tolerant, and requires relatively fertile yellow soil and yellow-brown soil (acidic, slightly acidic soil). It is relatively tolerant of water and moisture. Taxus wallichiana var. mairei has relatively strong sprouting ability, and sprouting twigs are often seen on the trunk, but growth is relatively slow.
Shade-tolerant tree species, likes shady and moist environments. It likes a warm and humid climate. It grows naturally in acidic soil rich in humus in valleys, beside streams, and on gentle slopes. It can also grow in neutral soil and calcareous soil. It is not tolerant of drought and barren conditions, nor of low-lying water accumulation. It rarely has pests and diseases, grows slowly, and has a long lifespan.
Conservation status
Taxus wallichiana var. mairei has dense branches and leaves and a beautiful tree shape. When the seeds mature, the fruits cover the branches and are delightful. It is suitable for solitary planting as an accent in a corner of a courtyard, and can also be planted in pairs at gates or road junctions on the shady side of buildings, or in groups on slopes, lawn edges, pond edges, and forest edges. It is suitable for use in scenic areas as a middle- and lower-layer tree species configured with various coniferous and broad-leaved tree species. Abroad, European yew is used for shaped hedges with very good results.
National second-class protected plant and an excellent precious tree species. The wood is hard and difficult for axes to cut into. There is a saying, "A thousand firs and ten thousand firs cannot match one branch of red Torreya." The sapwood is yellowish white, the heartwood is red, hard in texture, fine-grained, beautiful in appearance, not warping or splitting, and strongly rot-resistant. It can be used for construction, high-grade furniture, interior decoration, vehicles, pencil shafts, and so on. The seeds have relatively high oil content and are a rare medicinal material for expelling roundworms and relieving indigestion.
Protection measures
Taxus wallichiana var. mairei is relatively widely distributed, mostly spread by birds through feeding, so it is very scattered and sporadic. Because the wood is good and the color beautiful, destruction is more serious. At present, the most important thing is to stop the destruction of existing resources, while strengthening propagation work, introducing it as a courtyard ornamental tree species, and expanding cultivation to achieve the purpose of preserving the species. Propagated by seeds. The seeds have a dormancy period and must undergo low-temperature stratification treatment before they can emerge in the same year. Seedling growth is relatively slow.
Current status
Rare species. Although the distribution area of Taxus wallichiana var. mairei in Guizhou Province is relatively broad, this species is scattered within its distribution area, and the population is sparse. If not protected, it is at risk of becoming gradually endangered.
Distribution
Taxus wallichiana var. mairei is distributed in Zunyi, Fenggang, Fanjing Mountain, Leigong Mountain, Weng'an, Zhenyuan, Tianzhu, Jinping, Liping, Libo, and other places. It also occurs in Taiwan, China, Fujian, Zhejiang, Anhui, Jiangxi, Hunan, Hubei, Shaanxi, Sichuan, Yunnan, Guangxi, and Guangdong. This species is a Tertiary relict plant endemic to China, and the type locality is Fanjing Mountain in Guizhou.
There are 11 species of Taxus worldwide, distributed in temperate to tropical regions of the Northern Hemisphere. China has 4 species and 1 variety, namely Taxus chinensis, Taxus cuspidata, Taxus wallichiana var. yunnanensis, Taxus wallichiana var. mairei, and Taxus wallichiana, distributed in Northeast, South China, and Southwest China. In Sichuan, it is mainly distributed in Maoxian, Heishui, Ma'erkang, Wenchuan, Luding, Kangding, Xichang, Huili, Miyi, and other areas.
Cultivation techniques
1. Site selection and fertilization
Choose loose, humus-rich, neutral or slightly acidic high mountain terraces, and deep moist brown soil or dark brown soil on both banks of valleys and streams. Deep plow, level, and dig holes at a plant and row spacing of 0.4 m x 1.0 m or 0.4 m x 0.4 m, with a hole depth of 40 cm, ready for planting.
2. Propagation methods
Use seed propagation and cutting propagation, mainly by raising seedlings and transplanting.
(1) Seed seedling raising
① Seed collection and germination promotion. In mid-to-late October, collect seeds when the fruits turn dark red. These seeds are physiologically after-ripened and need 1 year of wet sand storage before they can germinate. The method of outdoor natural alternating wet sand stratification storage is often used to treat the seeds to increase the germination rate.
② Nursery selection and land preparation. Generally, adapting to local conditions, raising seedlings and transplanting under pine forests is better. Choose an established forest land of slash pine or masson pine with a canopy density of 0.6-0.7 and no pests or diseases as the nursery site, requiring a gentle slope, deep upper soil, and good drainage. In August to September, clear the weeds and shrubs in the forest, arrange into horizontal terraces, and dig deep 20-30 cm. In November, shallow plow and harrow finely. During land preparation, apply 40-60 loads/mu of decomposed base fertilizer (1 mu = 1/15 hectare, the same below), divide into beds, with a bed height of 15-20 cm and a width of 1.2 m. After leveling the bed surface, use a 15 cm wide wooden board to press out sowing furrows 2 cm deep, with a furrow spacing of 20 cm.
Nursery site selection and fertilization: The nursery site should preferably be paddy field soil with deep soil layers, loose structure, rich organic matter, good drainage, and not exposed to western sun (must be paddy field soil harvested in the same year). For land preparation, after harvesting the middle and late rice, deep plow once after the soil dries, break up the soil once, and then divide into beds. Bed width 1.5 m (net bed surface width 1.2 m, path width 0.3 m); bed height 20 cm, and the length of the seedbed depends on the nursery site. While preparing the land and making beds, apply about 8000 jin of decomposed pig and cattle manure per mu, 200 jin of quick-dissolving high-quality compound fertilizer, and mix in 6 to 8 jin of carbofuran to control underground pests. After turning the fertilizer into the soil layer and leveling the bed surface, fill the bed surface with yellow subsoil to a thickness of 5 cm.
③ Timely sowing. Generally sow in early spring. After the seeds have been stored for 1 year, when 30% of the seeds have cracked and shown white, sieve out the seeds in time, disinfect them in a 0.2% potassium permanganate solution for 10 minutes, then rinse them clean with clear water. After drying off the surface water, sow them evenly in the furrows. Mainly drill sowing, with a seed spacing of 5-7 cm. Broadcast sowing can also be used. After sowing, dig up yellow soil from under the pine forest that contains mycorrhizae and has been sieved to cover the seeds, with the thickness just enough that the seeds are not visible. During the seedling stage, pay attention to shading. At sowing, cover with rice straw so that the soil is not visible. Build a shade shed during the seedling stage, with a light transmittance of 60%. Then spread moss to protect the seedlings, protect the seedbed from sunlight and rain, and keep the soil loose and moist regularly. The seed emergence rate is above 70%.
Sowing is divided into broadcast sowing and drill sowing: broadcast sowing is to evenly scatter the seeds on the seedbed filled with yellow subsoil, cover the seeds with yellow subsoil just until the seeds are not visible, and then cover the entire seedbed with moss. For drill sowing, select a 15 cm wide wooden board and press sowing furrows 2 cm deep on the seedbed filled with yellow subsoil, with a distance of 15 to 20 cm between sowing furrows. Sow the seeds evenly in the furrows, cover the seeds with yellow subsoil to a thickness of 1 cm, and then cover the sowing furrows with moss.
It should be noted that: first, strictly control the sowing rate, using 15 kg of seed per mu, otherwise it will seriously affect the qualified emergence rate of 2-year-old seedlings; second, after sowing, broadcast sowing must cover the entire seedbed with moss, while drill sowing only needs to cover the sowing furrows with moss. After the seedlings emerge, do not remove the moss, but keep it on the seedbed for a long time. The advantages of moss protecting seedlings are: protecting the seedbed from rain splash and direct sunlight, preventing seedlings from being scorched by sunlight and avoiding death by suffocation from mud sticks formed when stems and leaves are stained with mud, and regularly keeping the soil loose and moist, reducing the labor for cultivating and weeding. However, the moss covering should be thin and not too thick. If there is a long drought without rain, fine yellow loam can be used to press down the moss, or a sprayer can be used to spray water to keep the seedbed moist.
(2) Cutting seedling raising
During the tree dormancy and bud-break period, choose a mixed medium of sand, sawdust, and perlite as the cutting soil. Choose 1-4 year old lignified seedling branches, cut the cuttings into small sections 10 cm, 15 cm, or 30 cm long. When cutting branches, the cuts should be smooth, the lower cut horse-ear shaped, and leaves below 2/3 removed. Choose agents such as ATP, ABT, NAA, IBAA, etc. to treat the cuttings, then insert them and cover with film. The cutting survival rate is generally above 85%. During the seedling stage, pay attention to keeping warm and build a low shed for shading. Transplant the following year.
From May to June each year, cut current-year semi-lignified branches as cuttings, choosing mother trees under 10 years old. Length 15-20 cm, cut off lower small branches, cut the needles into horseshoe shapes, and soak in ABT No. 7 rooting powder at a concentration of 30 x 10-6 to 50 x 10-6 for 3-12 hours. Then insert the cuttings into a seedbed with river sand as the medium. The seedbed should be 1 m wide and of suitable length, with a cutting depth of 3-5 cm. Row and plant spacing 10 cm x 8 cm, then spray water immediately. Build a frame over the seedbed, cover with plastic film, spray water 2-3 times a day, and after half a month spray water once a day. Generally keep the soil temperature at 20-30°C, avoid strong light, and roots can form in 30-40 days. During this period, foliar fertilizers such as brassinosteroid can be sprayed to promote growth.
After the seedlings have rooted, manage them carefully to promote vigorous growth, and ventilate and expose them to light appropriately to harden the seedlings and increase stress resistance. After hardening, they can be transplanted into larger seedbeds.
Seedlings generally grow in the seedbed for 2-3 years, with regular spraying of growth hormones and foliar fertilizers and careful management each year. When the seedlings are 50-100 cm tall, they can be planted on mountain land for afforestation in large patches. The planting time can be late autumn or spring, with a plant and row spacing of 3 m x 4 m, and they can also be planted along streets and in parks as ornamental trees.
(3) Transplanting
Generally, seedlings raised from seeds after 1-2 years, or propagated by cuttings after about 1 year, can be transplanted when the seedling height reaches 30-50 cm. Transplanting is carried out in October to November or February to March before bud break, with 1 seedling planted per hole, watered, and properly shaded.
3. Field management
After the seeds emerge, weeds must be pulled frequently. Apply topdressing 1-2 times each year. In rainy seasons, prevent water accumulation to avoid root rot. After planting, cultivate and weed 2 times each year. After the forest land closes, generally only winter cultivation and weeding are done, and earth is banked up 5 times. Combine cultivation and weeding with topdressing, mainly using farmyard manure as the fertilizer source. During the young tree stage, remove sprouts to ensure the trunk is straight and grows quickly.
1) Shading of seedlings: Before the seedlings emerge, the shade frame must be set up, with a height of 1.7 m. During the dog days, the seedbed must be shaded.
2) Pest and disease control: After the seedlings emerge, it is the rainy season. Because of abundant rain and high air humidity, the seedlings are susceptible to infection by pathogens and to root rot and damping-off, causing complete failure of seedling raising. Therefore, the key is prevention, that is, 7 days after the seedlings emerge, spray 800 times diluted thiophanate-methyl or half-strength Bordeaux mixture (0.5 copper sulfate, 0.5 jin lime, 100 jin water), spraying the seedling stems and the backs and surfaces of the leaves.
3) Cultivation, weeding, and fertilization: During seedling growth, pay attention to weeding and loosening the soil to improve soil aeration. The principle for weeding is: remove small ones, remove early. For topdressing in the early stage of seedling growth, mainly use nitrogen and phosphorus fertilizers, prepared with 10% dilute human manure and urine plus 0.4 jin urea, applied once every half month. Stop application in mid-September, remove the shade net, and keep the frame for use next year.
4) Seedling transplanting: If uneven sowing causes seedlings to be too dense or too sparse, transplant the seedlings from late May to mid-June, thinning dense areas and filling sparse ones. The transplanting method is: choose cloudy and rainy days or after rain for transplanting, cover well with moss, rinse the root area with clear water, and transplant.
4. Harvesting and processing
Cultivated Taxus can generally be appropriately harvested for branches and leaves after the 3rd year. Fresh leaves can be harvested throughout the four seasons. However, based on the accumulation of active ingredient content, young branches are better for branches, and old leaves are better for leaves. October is the best harvest period. After harvesting, if not used for fresh processing, spread them out in time to dry in a ventilated shade or in the sun.
5. Planting prospects
Taxus is a plant left from the Tertiary Period and is called a "living fossil" in the plant kingdom. Because its resources are scarce, it is listed as a rare tree species in the world for protection. Taxus integrates medicinal, timber, and ornamental uses and has extremely high development and utilization value. Taxol extracted from Taxus bark and branches and leaves is a world-recognized anticancer drug, selling for 5-10 million US dollars per kilogram. Taxol is used to treat advanced breast cancer, lung cancer, ovarian cancer, head and neck cancer, soft tissue cancer, and digestive tract cancer. Taxus branches and leaves are used to treat leukemia, nephritis, diabetes, and polycystic kidney disease. Taxus natural resources are scarce and medicinal sources are in short supply, so various places are carrying out extensive research and development on it. Every part of Taxus is valuable, so the Taxus tree is also called the "golden tree," and its planting prospects are promising. Places with mature conditions can develop it appropriately.
6. Taxus wallichiana
National Class I key protected wild plant (approved by the State Council on August 4, 1999)
Taxus wallichiana, also called Himalayan yew, is one of China's 4 species and 1 variety of Taxus, and is an endemic tree species of Tibet. The other 3 species and 1 variety are: Taxus wallichiana var. yunnanensis, Taxus cuspidata, Taxus chinensis, and Taxus wallichiana var. mairei (variety).
Morphological characteristics
Evergreen small tree or shrub, with spreading or upward-extending branches; bark light reddish brown, splitting into thin flakes and falling off; twigs irregularly alternate, light green, later becoming light brown or reddish brown; winter buds ovate, bud scales imbricate, the basal bud scales usually triangular-ovate, apex acute, slightly keeled on the back, falling off or a few persistent at the base of the twigs. Leaves spirally arranged, irregularly two-ranked, linear. Usually straight, 1.5-3.5 cm long, about 2.5 mm wide, apex with a raised sharp point, glossy green on the upper surface, midrib raised, lower surface with two pale yellow stomatal bands 2 times wider than the green marginal band; with a short petiole. Dioecious, cones solitary in leaf axils; male cones globose, with many spirally arranged stamens, with short peduncles; female cones almost sessile, with 1 ovule at the upper end bearing a disc-shaped aril, and several imbricate bracts surrounding the base. Seeds mature in the same year, nut-like, columnar-oblong, borne in a fleshy, red, cup-shaped aril, about 6.5 mm long, 4.5-5 mm in diameter, slightly flattened, with blunt ridges on both sides below, apex with a short point, hilum elliptical.
Biological characteristics
The climate of the distribution area is characterized by warm summers and cool winters, with four distinct seasons, snow cover in winter, an average annual temperature of about 10°C, a maximum temperature of 16-18°C, a minimum temperature of 0°C, annual precipitation of 800-1000 mm, and an average annual relative humidity of 50-60%. It is cold-tolerant and also relatively shade-tolerant. During the growing period it requires sufficient temperature. It mostly grows in forests in relatively moist sections of river valleys and stream banks. The main community tree species are Pinus griffithii McClelland, P. roxburghii Sarg., Tsuga dumosa (D. Don) Eichler, and Quercus semicarpifolia Smith., etc. The flowering period is May, and the seeds mature from September to October.
Propagated by seeds. The embryo dormancy period is relatively long. After seed collection, the seeds must be stored in wet sand stratification at low temperature, sown in spring, and the germination period may be extended to the second year. It can also be propagated by cuttings.
Economic uses
Taxus wallichiana is the species with the smallest distribution area in China and also the smallest resource reserves, but its resources have basically not been destroyed. It is mainly used for medicine, ornamental purposes, and scientific research.
7. Himalayan Yew
Latin name: Taxus wallichiana Zucc.
Chinese name: Himalayan Yew
Distribution
In China it is found only in forests at elevations of 2800-3100 m in Gyirong, Tibet. It is also distributed from Afghanistan to Nepal.
Current status
Endangered species. This species is endemic to the Himalayas and in China occurs only in Gyirong, Tibet, where the number of plants is extremely small and they are often cut down. If effective protection measures are not taken, it risks becoming extinct in China.
Morphological characteristics
Evergreen small tree or shrub, with spreading or upward-growing branches; bark pale reddish-brown, splitting and peeling off in thin flakes; branchlets irregularly alternate, pale green, later turning pale brown or reddish-brown; winter buds ovoid, bud scales imbricate, the basal bud scales usually triangular-ovate, apex acute, slightly ridged on the back, deciduous or a few persistent at the base of branchlets. Leaves spirally arranged, irregularly distichous, linear, usually straight, 1.5-3.5 cm long, about 2.5 mm wide, apex with a raised sharp point, glossy green above with a raised midrib, beneath with two pale yellow stomatal bands twice as wide as the green marginal bands; with a short petiole. Dioecious, strobili solitary in leaf axils; male strobili globose, with numerous spirally arranged stamens, with a short stalk; female strobili almost sessile, with 1 ovule bearing a disc-shaped aril at the upper end, surrounded at the base by several imbricate bracts. Seeds mature in the same year, nut-like, columnar-oblong, borne in a fleshy, red, cup-shaped aril, about 6.5 mm long, 4.5-5 mm in diameter, slightly flattened, with obtuse ridges on both sides below, apex with a short point, hilum elliptic.
Characteristics
The climate of the distribution area is characterized by warm summers and cool winters, with four distinct seasons, snow cover in winter, an annual mean temperature of about 10°C, a maximum temperature of 16-18°C, a minimum temperature of 0°C, annual precipitation of 800-1000 mm, and an annual mean relative humidity of 50-60%. It is cold-tolerant and fairly shade-tolerant, and requires sufficient temperature during the growing season. It mostly grows in forests in relatively moist sites in river valleys and along gullies. The main community tree species are Pinus griffithii McClelland, P. roxburghii Sarg., Tsuga dumosa (D. Don) Eichler and Quercus semicarpifolia Smith. The flowering period is May, and the seeds mature in September-October.
Conservation value
As an endemic species of the Himalayan region, it has scientific significance for the study of the flora and the taxonomy and distribution of the genus Taxus.
Conservation measures
At present, felling should be strictly prohibited and the natural vegetation of the sites should be protected. It is suggested that a nature reserve be established in Gyirong, or that the forestry department give key protection to rare plants such as the Himalayan Yew, Himalayan Long-leaved Pine and Long-leaved Spruce. Propagation trials should also be carried out to expand planting.
Cultivation points
Propagated by seed. The seed embryo has a relatively long dormant period; after collection the seeds must be stored in low-temperature stratification with moist sand and sown in spring, and germination may be delayed until the second year. It can also be propagated by cuttings.
Supplement
Geographical distribution: In China it is found only in forests at elevations of 2800-3100 m in Gyirong, Tibet. It is also distributed from Afghanistan to Nepal.
8. Himalayan Yew
Himalayan Yew
Latin name: Taxus wallichiana var. wallichiana
Aliases: Yunnan Yew, Chibaisong, Zisha
Division: Gymnospermae
Family: Taxaceae
Genus: Taxus
It grows in mountainous areas at elevations of 2000-3500 m.
It is produced in China in Sichuan, Yunnan, Tibet and other places.
Endemic to China. National first-class protected plant.
9. Pacific Yew
Leaves of the Pacific Yew. The Pacific Yew (Taxus brevifolia) grows on the west coast of the United States.
Paclitaxel can be extracted from the bark of the Pacific Yew.
Scientific classification
Kingdom: Plantae
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Taxaceae
Genus: Taxus
Species: Pacific Yew T. brevifolia
Binomial name
Taxus brevifolia
Nutt.
10. Media Yew
Family Chinese name: Taxaceae
Family Latin name: Taxaceae
Genus Chinese name: Taxus
Species Chinese name: Media Yew
Species Latin name: Taxus madia
The Media Yew is one of the species of yew. The yew (scientific name Taxus mairei) is a relict plant from the Quaternary glacial period and a rare and endangered species in the world. There are eleven species worldwide, and at present China has four species and one variety, namely the Yunnan Yew, Tibetan Yew, Japanese Yew, Chinese Yew and Southern Yew (variety). The Media Yew was introduced to China from Canada in the mid-1990s. It is now cultivated in Sichuan, Ziyuan in Guangxi, Shandong and other places.
The Media Yew (Taxus madia) is native to the United States and Canada and is a natural hybrid, with the Japanese Yew (T. cuspidata) as the female parent and the European Yew (T. bauata) as the male parent. It has a history of nearly 100 years of growth and development in the United States and Canada. It is an evergreen shrub with an extremely large biomass and a short growth period. Its main root is inconspicuous, its lateral roots are well developed, its branches and leaves are luxuriant, its sprouting ability is strong, and it is tolerant of low temperatures, withstanding temperatures as low as -25°C. It can be planted in most parts of the country. It grows fast, with measured annual growth of 40-50 cm, and up to 60-70 cm at most, which is 300-700% of the growth of domestic yews (Chinese Yew, Yunnan Yew, etc.). The biomass accumulation of 3-4 year old plants is 600-800 per plant per year, and at 5 years old it yields more than 1.5 kg of fresh material, which can be used to extract paclitaxel. The following year it can sprout new branches and leaves again, and its biomass is even greater than the harvest of the previous year.
In the mid-1990s, China introduced Canadian yew seedlings for trial planting in Sichuan. According to determinations by authoritative institutions, the introduced Media Yew has stable biological characteristics with no variation, and its paclitaxel content is close to that of the place of origin, with the content in some samples even higher than that of the place of origin. Paclitaxel in natural yew trees is generally distributed in the bark, and the utilization rate of the whole plant is low. In the Media Yew, however, all parts of the plant contain paclitaxel, with the branches and leaves containing more than 0.03% and the root system reaching 0.06%. The whole plant is used for extracting paclitaxel, giving a high utilization rate of the plant and, after deep processing, even higher comprehensive economic value.
Through cultivation and selection, the Media Yew has been developed into more than 10 strains, among which Taxus media is one of the yews approved by the US FDA for the extraction of paclitaxel. The paclitaxel content in the branches and leaves of 4-5 year old Media Yew is higher than the paclitaxel content in the bark of 70-80 year old natural yew trees. The paclitaxel content of wild yews, including domestic varieties, is generally between 0.004 and 0.01%, while that of the Media Yew is 0.03-0.06%, which is 8-10 times that of natural yew, and it can be planted in most parts of China.
The successful introduction and domestication of this rare plant, the Media Yew, is conducive to protecting precious wild yew resources and also opens up broad prospects for developing the yew, this golden plant. It grows quickly and is highly adaptable to the environment, and can be used to establish soil and water conservation forests and water source conservation forests and to improve the ecological environment.
In addition, the Media Yew is evergreen all year round, with bright red fruits in autumn, giving a healthy and full appearance. It tolerates pruning well and is easy to shape, and has high horticultural value.
11. Dwarf European Yew
Species name: Dwarf European Yew
Scientific name: Taxus baccata Ericoides
Aliases:
Family: Taxaceae Genus: Taxus
Morphological characteristics: Evergreen dwarf shrub, a dwarf variety of the European Yew. Leaf tips golden yellow.
Growth habits: Cold-tolerant, with extremely strong shade tolerance, a good material for landscaping in high-latitude regions.
Distribution range of yew
In China, yew is widely distributed in Lechang, Guangdong, Shaanxi, Hubei, western Anhui and as far as Sichuan, the Fanjingshan and Fodingshan areas of Tongren City in Guizhou, most of southwestern Chongqing, the Dabanying primeval forest in Youyang, and southern Gansu and other places.
Except for Austrotaxus spicata in Australia, which is produced in the Southern Hemisphere, all other yews are produced in the Northern Hemisphere. Chinese yew has 4 species and 1 variety, distributed in most parts of China. The Japanese Yew is mainly distributed in the Changbai Mountains and Heilongjiang area of Jilin Province, with a small distribution in the mountainous areas of eastern Liaoning. The Southern Yew is mainly distributed in pure forests in eastern Yunnan, southwestern Yunnan and eastern Yunnan, mostly as scattered trees in forests. The yew of Yunnan mainly grows and is distributed in mountainous areas at elevations of 2600-3500 m in Lijiang, Diqing, Nujiang and Dali, in a belt-like distribution and in very small numbers. In Daqiao Town, Ruyuan County, a small town of only more than 300 sq km, there are actually more than 100,000 yew trees rooted here. This is currently the densest growth area of wild yew in China.
The Yunnan Yew is mainly distributed in 16 counties in western Yunnan and prefectures, with a total area of about 90,000 sq km. It is characterized by wide distribution, scattered growth, no pure forests, and mostly scattered trees in forests. The Southern Yew is mainly distributed in pure forests in eastern Yunnan, southwestern Yunnan and eastern Yunnan, mostly as scattered trees in forests.
Large numbers of natural yews are distributed in Laowan Village, Chaoyi Township, Suining County, Shaoyang City, Hunan Province; Jiaochemiao Village, Yangmingshan, Shuangpai County, Yongzhou City; and Huangshan District, Huangshan City, Anhui Province. It is also cultivated in Sichuan, Ziyuan in Guangxi, Shandong and other places, and is also distributed in western Jiangxi (Yichun, Tonggu area). The Tibetan Yew is mainly distributed in northwestern Yunnan and southern and southeastern Tibet.
Medicinal or dietary therapeutic value of yew
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Medicinal value
The medicinal value of yew is mainly embodied in its extract, a secondary metabolite derivative, paclitaxel. Paclitaxel was first isolated from the bark of the Pacific Yew as an anti-tumor active ingredient. It is one of the best drugs for treating metastatic ovarian cancer and breast cancer, and also has significant efficacy against lung cancer and esophageal cancer, and clearly inhibits nephritis and parvovirus inflammation.
The roots, stems and leaves of yew can all be used as medicine. They can treat difficult urination and eliminate swelling and pain, and have therapeutic effects on diabetes, irregular menstruation in women and increased blood volume. Yew can also be used for postpartum conditioning and has certain therapeutic effects on women's conditions.
Uses and purposes of yew: ornamental use
The yew has a beautiful and elegant tree shape and is evergreen all year round. The color combination of red and green when the fruits ripen is intoxicating. It can be widely used in soil and water conservation, horticultural ornamentation and other aspects. It is an excellent tree species for improving the ecological environment and building beautiful mountains and rivers in the new century, and is now often used for high-end courtyard landscaping and ornamentation.
Scientific research use
The yew is a rare and endangered plant left over from after the Quaternary glaciation, with very few natural distributions worldwide, and is listed as a national first-class key protected plant. It has extremely high scientific research value in many aspects.
Economic value
According to a report on page 5 of the People's Daily on October 17, 2001, the price of high-quality taxol on the international market had reached as high as 180,000 USD per kilogram in 2000. The heartwood is orange-red, the sapwood pale yellowish-brown, the grain straight, the texture fine, the specific gravity 0.55-0.76, hard and durable, with little cracking after drying. It can be used as timber for construction, vehicles, furniture, utensils, farm tools and stationery.
Air purification
Yew can effectively purify indoor air. It can absorb indoor toxic gases; for example, formaldehyde from newly renovated homes can be well absorbed, reducing the content of toxic gases indoors. The yew itself can absorb carbon dioxide and release oxygen, making it a natural oxygen bar that can be used both day and night. It belongs to the CAM category of tree species and can prevent respiratory diseases and maintain the cleanliness and safety of the air. Modern environmental monitoring has proven that yew can absorb many toxic gases such as sulfur dioxide and carbon monoxide into its body and purify indoor air.
Other uses
Yew wood is fine and dense, bright red in color, tough and durable, and is a precious timber tree species. It is often used for carving and making high-grade furniture, handicrafts, etc.; the wood is rot-resistant and can be used as timber for civil engineering; the seeds have an oil content of 60% and have special development value.
Landscaping uses of yew
Yew also has very broad development prospects in landscaping and indoor bonsai. For example, high-grade bonsai made from rare yew trees. Bonsai of the Japanese Yew treated with dwarfing techniques have a simple and elegant shape, with compact but not dense branches and leaves, spreading but not loose. The red stems, red branches, green leaves and red fruits give it multiple ornamental values of stem, branch, leaf and fruit viewing.
Yew can be planted at 2000 seedlings per mu, and after three years it can produce more than 1 ton of branches and leaves per year. It is also suitable for planting in front of and behind houses, on barren slopes and open land, and along roadsides. Plant once and benefit for many years, with remarkable benefits. The yew has a beautiful tree shape, and the color combination of red and green when the fruits ripen is intoxicating. It can be widely used in soil and water conservation and in forestry and horticultural ornamental forests, and is an excellent tree species for improving the ecological environment and building beautiful mountains and rivers in the new century.
It also has very broad development prospects in landscaping and indoor bonsai. For example, high-grade bonsai made from rare yew trees sell for 300,000 yuan per pot in Beijing, Shanghai, Shenzhen and other places, becoming a new favorite for urban greening and home beautification, and are vividly called precious "money trees" by people.
Cultural background of yew
History
Yew can grow into tall trees, and some individual plants can even grow for thousands of years without declining. It can be used both as a medicinal variety and as a greening variety. In folk legends, the Japanese Yew has long been known as the "sacred feng shui tree".
Yew is a shallow-rooted plant with an inconspicuous main root and well-developed lateral roots. It is recognized worldwide as an endangered natural rare anti-cancer plant. It is an ancient relict tree species left over from the Quaternary glaciation and has a history of 2.5 million years on Earth. The United Nations has also explicitly prohibited its felling, and it is truly a "plant panda".
Conservation status
Because the bark of yew contains an anti-cancer substance, paclitaxel, many people enter the forests to strip the bark, causing the number of yews to drop sharply.
The reason the yew suffered this catastrophe was that in the early 1990s, a certain American company discovered that paclitaxel in yew bark has anti-cancer effects. When the news spread to China and to Yunnan, people suddenly realized that treasure was right beside them. People frantically stripped the bark of yews, and no one took the detailed Regulations on the Protection of Precious Tree Species of Yunnan Province to heart. As a result, more and more yew lives came to an abrupt end overnight.
The State Forestry Administration once issued clear instructions on the "Yew Project" carried out: "Yew is a first-class protected tree species in China, with both good ecological benefits and extremely high economic value. The state supports vigorously establishing yew forests in appropriate areas, and all sectors of society participating in afforestation through contracting, leasing, auction, joint-stock cooperation and other forms should be advocated and encouraged."
Nature reserves
Liangyeshan National Nature Reserve is China's first national-level yew nature reserve, and also the only national-level nature reserve with the Southern Yew as its protection target.
The Muling Japanese Yew Nature Reserve was approved as a national-level nature reserve in 2009, and the more than 160,000 Japanese Yew trees known as the "plant panda" will be further effectively protected.
This nature reserve was originally a provincial-level reserve, and is the largest and best-preserved concentrated distribution area of wild Japanese Yew discovered so far in the Northeast forest region. The Japanese Yew, also known as Zisha, is a world endangered species and a national first-class rare protected tree species.
The Muling Japanese Yew Nature Reserve is located at the northern end of the Changbai Mountains and the southern foot of the Lesser Khingan Mountains, within the jurisdiction of the Muling Forestry Bureau, with a total area of 35,000 hectares.
Market demand
Although China's yew resources account for more than half of those of other countries in the world, they are still far from sufficient given the world demand for paclitaxel. Since the US Food and Drug Administration (FAD) approved paclitaxel as a drug for treating advanced cancer in 1992, excessive felling of China's wild yew resources has become increasingly serious, and wild yew resources have suffered severe damage. Moreover, many biological characteristics of wild yew limit the development of natural communities. According to statistics: the annual number of cancer cases worldwide is more than 10 million. If paclitaxel is extracted at 0.006%-0.06%, 700-1000 tons of yew bark would be consumed each year. Even if all the world's yew bark were stripped clean, it could only meet short-term needs. Therefore, artificially propagating and developing yew resources and establishing yew timber forest bases for medical raw materials is extremely urgent.
Import and export management
Yew is a rare resource with important medical value. In order to protect yew resources, the state has issued strict management regulations on the import and export of yew and its products. The following is the management notice issued in 2004 by the National Endangered Species Import and Export Management Office and the General Administration of Customs:
1. Strictly implement the certificate management system.
2. In order to improve the review efficiency and approval quality of import and export applications for yew and its parts and products, a filing system shall be implemented for enterprises engaged in artificial cultivation, collection and utilization, and business production of yew, as well as import and export companies of yew and its parts and products.
3. According to Article 18 of the Regulations on the Protection of Wild Plants and the Notice of the State Forestry Administration on Issues Concerning Strengthening the Protection and Management of Yew Resources (Lin Hu Fa [2002] No. 287), commercial export of wild yew and its parts and products is prohibited.
4. For any application to import Himalayan Yew and its parts and products from a contracting party to the Convention by any trade method, the export license of the other country shall be provided, and it shall be handled as an import of a species listed in Appendix II of the Convention.
5. For the import and export of Himalayan Yew and its parts and products (including by way of processing trade), the customs shall handle the relevant inspection and release procedures against the CITES Permit for Import and Export; for the import and export of other species of yew and their parts and products (including by way of processing trade), the customs shall handle the relevant inspection and release procedures against the Permit for Import and Export of Wild Animals and Plants.
6. For entry from abroad into bonded zones, export processing zones and bonded warehouses, as well as for exit from bonded zones, export processing zones, bonded warehouses and export supervision warehouses, the customs shall handle inspection and release procedures against the relevant import and export documents in accordance with Article 5.
Flower language of yew
Flower language of yew: proud.
The yew is a rare tree species in the world. Even worldwide, such tall trees reaching into the clouds are rarely seen. The towering yew appears strong and proud.
Yew pictures
What are the propagation methods of yew?
Image: Yew
[Common question] What are the propagation methods of yew?
[Expert answer]
1. Seed propagation
Yew is mostly propagated by seed. When propagating seedlings from yew seeds, attention should be paid to the storage method of the seeds; mixed storage with sand or temperature-controlled treatment should be used, which has a very good effect on sprouting after overwintering and breaking the dormancy habit. Before sowing, the seed coat should be rubbed and damaged, the seeds soaked in warm water, and chemical and hormone treatments applied. Shading after emergence is the key to raising seedlings. It can prevent high-temperature scorching of the seedlings and maintain moisture; a light transmittance of 40% is appropriate. The emergence rate of both the Japanese Yew and the Southern Yew can reach 70-80%, and the emergence temperature is required to be above 15 degrees.
The dynamic growth of seedling plants is as follows: the plant height and stem diameter of seedlings grow slowly in the first two years after emergence, with plant height generally increasing by about 10 cm per year; after one year of transplanting, growth accelerates. From 3 to 5 years, the annual increment can reach 20-30 cm.
2. Cutting propagation
For the cutting propagation of Taxus (yew), softwood cuttings are best in spring, while hardwood cuttings are best in autumn. Generally, cuttings should be placed under a low frame with shading. The usual survival rate of cuttings can reach over 70%. In contrast, conventional cuttings achieve only about 3% to 20%. The shading rate should be no less than 60%. The base of the cuttings should undergo careful rooting treatment. At the beginning, humidity should be kept intermittently at around 75 to 85%. Avoid strong winds that cause water loss.
The factors affecting the survival rate of cuttings generally include: tree age, temperature, concentration of chemical treatment, substrate, season, humidity, variety, and other human factors.
During the rooting process in the first year, the above-ground part of the cutting seedling grows slowly, but rooting is rapid and lateral roots are well developed. After transplanting in the second year, further shading treatment and seedbed management are required. With the corresponding environmental conditions ensured, growth speeds up. Growth is fastest in summer, and slow in winter and spring. At this time, attention should be paid to temperature changes, as prolonged dryness can cause growth inhibition or sudden death. However, after the seedlings are strengthened in the seedbed, the afforestation survival rate of Taxus is very high. Very few die, and they grow rapidly.
3. Tissue culture
Tissue culture makes use of the totipotency and clonability of plant cells. Young stems, needles, bark, cambium, aril, embryos, etc. of Taxus plants are used as explants for culture research.
(1) Excellent Taxus varieties are selected as explants and inoculated into the culture medium. Through steps such as callus formation, rooting, and formation of seedling bud clusters, a large number of tissue-cultured seedlings can be obtained in the laboratory. After substrate transplanting, hardening, and inspection for disease prevention, they become seedlings for production use.
(2) The ratio of early to late callus formation in Taxus differs between different species and between different plants of the same species. It is also related to factors such as explant type, sampling site and collection season, light conditions, and culture medium type.
[Editor's review] The above is the article "Propagation Methods of Taxus" introduced to you by the First Agricultural Economics editor. For more related materials, such as"What kind of planting environment is suitable for Taxus?" "Cultivation Methods and Precautions for Taxus"etc., please follow the relevant columns or special channels of First Agricultural Economics. Thank you for your attention!