Detailed Explanation of Key Techniques for Seed Propagation of Taxus wallichiana var. mairei

Taxus wallichiana var. mairei, also called the beautiful yew, is a plant of the genus Taxus in the family Taxaceae. Because its trunk is upright and tall, it is evergreen through all four seasons, its branches are opposite and dense, its leaves are symmetrical and extremely verdant, and its fruit resembles agate with a glowing red light, it has extremely strong ornamental value. It is most suitable for planting in shaded or semi-shaded spots in courtyards, and is the best tree species for courtyard beautification. At the same time, it is a raw material for producing the anti-cancer substance paclitaxel, and has extremely high medicinal value.

The propagation routes of Taxus wallichiana var. mairei include two methods: sexual propagation and asexual propagation. And seed propagation (that is, sexual propagation) is the main propagation method of Taxus wallichiana var. mairei. Its main technical measures are briefly introduced as follows:

Collect seeds.

The seeds of Taxus wallichiana var. mairei mature in October-November. At this time the fruit is crimson red, and the seeds are obovate or broadly ovate, reddish brown, and glossy; pick them.

Seedbed preparation.

The seedling-raising site should be chosen as flat terrain, with drainage and irrigation, deep soil layer, loose texture, sheltered from wind and shaded, rich in humus, and slightly acidic (pH 6.0-6.5) or neutral soil. Level the ground and make beds. After making the beds, the soil must be disinfected. About 180 times water can be added to 40% formalin, and 10-15 kg of the diluted solution per square meter can be used for spraying, then cover the seedbed with plastic film for one week, then uncover the film, and level the seedbed before use.

Seed treatment.

The seeds of Taxus wallichiana var. mairei have a long dormancy period, lasting more than 1 year. If not properly treated, some may take 2-3 years to germinate gradually, and some may even lose vitality during dormancy and no longer germinate.

There are three treatment methods: First, sow immediately after collection. After disinfecting the collected seeds with formalin, sow them immediately into the seedbed to prevent the seeds from losing water and thus losing vitality. However, this method produces few seedlings in the current year. Second, stratify and store the seeds with low-temperature wet sand to promote germination. Third, bury the seeds in soil for 1 year, and sow them the following year.

Sowing.

Use drilling. The row spacing is 13-15 cm. For those that have been stratified and stored to promote germination or buried in soil, after taking out the seeds, first sieve out the seeds, wash the seeds clean with clear water, then soak the seeds in a 200-260 times aqueous solution of 40% formalin for 20 minutes, take them out and seal them for 1-2 hours, finally wash them clean with clear water, and place them in a container at a temperature of 20-25°C to promote germination. After the embryo begins to sprout, they can be sown. The sowing depth is about 2 cm. After sowing, cover with soil (the soil is best as sifted fine mycorrhizal soil), cover with grass, and water the seedbed thoroughly with a fine-hole watering can.

Management.

1. Erect a shade shed. Taxus wallichiana var. mairei is a strongly shade-loving, slow-growing tree species, and by nature likes a warm and humid ecological environment. If it is not properly shaded, the seedlings after germination are extremely likely to die because of poor resistance. Therefore, before the young buds emerge from the soil, the work of building a shed for shade must be done well. The shading degree is preferably about 50% light transmittance.

2. Cover with plastic film. Except for the places where sowing has been done, cover all the other soil of the seedbed with plastic film. This treatment can not only keep warmth and moisture and increase the seed germination rate, but also greatly reduce the amount of weed growth and lower management costs.

3. Thin seedlings. When the seedlings grow to 3-5 cm, thin them according to the principle of "remove the weak and keep the strong, remove the inferior and keep the superior", so that the seedlings are evenly distributed and the density is moderate. In addition, work such as drought resistance and drainage, fertilization and disease removal, loosening soil and pruning should also be done well.