A Detailed Guide to the Latest Seed Germination Methods for Cornus officinalis

The seed coat of Cornus officinalis is hard and lignified, and rich in a gelatinous substance that is difficult to dissolve in water under normal conditions. The embryo of the seed is tender and watery, and its sprouting ability is relatively weak, so it is very difficult for the shell to break and the seed to sprout in a short period. In nature, Cornus officinalis seeds need to go through at least 12-15 months of retting before they can sprout, and the germination rate is only below 50%. Let us now take a look at the germination methods for Cornus officinalis seeds!

Traditional germination of Cornus officinalis

1. Soaking in manure and urine for germination: a germination treatment method in which the seeds are placed directly in human manure and urine for soaking and then stored in water, but this method is affected by factors such as temperature, climate, and the pH of human manure and urine. The soaking time is not easy to control. Although the cost is relatively low, the germination rate and success rate are also relatively low.

2. Chemical soaking for germination: a treatment method using sulfuric acid, caustic soda, or hormones for rapid seed soaking, but because the concentration of the acid or alkali is not easy to control, although the shell is corroded, it easily damages the seed embryo, so it is mostly not adopted in production practice.

Seed treatment of Cornus officinalis

1. Seed selection: For superior Cornus officinalis seeds, the grains are plump and uniform in size. When cut open crosswise with scissors, the seed embryo is greenish-white, soft in texture, and has a fragrant odor. Immature seeds have thin and weak embryos that come off as soon as they are pried outward with a needle or wire, are blackish-yellow in color, and rot easily.

2. Processing method: The processing methods for Cornus officinalis medicinal material include boiling in water, steaming in a basket, hand-squeezing raw fruit, and machine processing. Seeds used for raising seedlings must be obtained by the hand-squeezing raw fruit method or machine processing method. The germination rate of raw seeds can generally reach more than 65%, while seeds that have been scalded or boiled in water have only a 5-10% germination rate, or may even fail to sprout at all or fail to survive the summer safely.

3. Degreasing treatment: Because the outer skin of Cornus officinalis seeds is hard and rich in gelatinous substance, soaking and degreasing must be carried out before sand storage treatment. The method is to pour the seeds into a corrosion-resistant container, then weigh out white alkali at a ratio of 8%, slowly pour the alkali into heated water to dissolve it, and then pour the alkali solution into the container holding the seeds. The alkali solution should preferably cover the seeds by 3-5 cm. Stir with a wooden stick 3-5 times a day. After 3 days, remove the seeds and pour off the remaining water, then soak the seeds again using the same method with a 3-5% alkali-to-seed ratio for 2 days, for a total of 5 days. Remove the seeds, rinse once with clean water, repeatedly rub them or use a ball mill to grind the shells so that the outer seed coat becomes noticeably thinner, then dry the seeds until they are 70% dry and set aside for later use.

4. Sand storage treatment: Because the embryo of Cornus officinalis seeds has after-ripening characteristics, after collection they need a period of natural dormancy, so sand storage is very important. In order to break the excessively long dormancy period, a suitable temperature must be provided for germination.

① Choose a sunny, dry, well-drained piece of land and dig a pit. The size of the treatment pit depends on the amount of seeds. The pit should not be too deep, generally 20-30 cm is suitable.

⟦NL>② Spread cattle, sheep, mule, or horse manure about 3 cm thick on the bottom of the pit, sprinkle a thin layer of fine sand 1-2 cm thick on the manure, and then evenly spread the seeds on the sand. The thickness should be 2-4 cm and must not be too thick, so as not to affect the quality of germination. Sprinkle another thin layer of sand on the seeds, then spread a 3 cm thick layer of cattle, sheep, mule, or horse manure, and sprinkle another layer of sand on the manure. Layer them in this way, generally 3-4 layers is enough. If too thick, germination will be insufficient and the germination rate will be affected.

5. Heating in a warm shed: Temperature is one of the necessary conditions for seed germination. In the rapid treatment of Cornus officinalis seeds, a suitable temperature can also break the excessively long seed dormancy period and promote earlier germination. The methods generally adopted include greenhouse heating, flue heating, and plastic warm shed heating. Among the three, the plastic warm shed method has lower cost and is relatively convenient and commonly used. The method is to cover with film in an arched shed according to the size of the treatment pit. Use strong cord on top and pull it tight to prevent wind from blowing it loose.

Daily management during germination

1. Moisture: Because Cornus officinalis seeds have already fully absorbed water during the soaking and degreasing process, during sand storage germination, unless the sandy soil is extremely dry, generally do not water, so as to prevent the seed embryos from rotting.

2. Ventilation: Seeds are also alive and also need necessary respiration, so once a month it is necessary to lift a corner of the warm shed to allow airflow. Each time, 8-12 hours is enough.

3. Time: After seed treatment, generally after 3-4 months the shed should be opened for inspection. When it is found that 10-20% of the seeds have broken shell and the embryos are in a state of sprouting and growth, they can be sown. This is to avoid excessively vigorous growth affecting the seedlings and wasting seeds.