(1) copper sulfate soaking: soak the seeds with 0.3% ~ 1% copper sulfate solution for 4 ~ 6 hours, take them out and dry them in the shade before sowing.
② Seed soaking with potassium permanganate: Soak seeds with 0.5% potassium permanganate solution for 2 hours (or soak seeds with 3% potassium permanganate solution for 30 minutes), take them out, seal them for half an hour, and then rinse them with clear water several times before sowing.
③ Soaking seeds with ferrous sulfate: Soak seeds with 0.5% ~ 1% ferrous sulfate solution for 2 hours, take them out, rinse them with clear water, and then dry them in the shade.
(4) Soaking the seeds with special sterilization solution: soaking the seeds with 800 times of special sterilization solution for 65,438+/-0.5 minutes to sow. Planted wood can be planted in the same year or after sand storage, and the direct seeding effect is the best.
Direct seeding makes the seeds spend the dormancy period in the nursery, eliminating the process of accelerating germination or storage. In the coming year, the seeds germinate early, emerge early and orderly, and the seedlings have long growth period, early lignification, strong growth, strong cold resistance and high seedling rate. When sowing in sand storage, the suitable time for sand storage is 15 ~ 20 days, which cannot be extended. After a long time, seeds will crack, which will affect the emergence rate. Bed sowing, furrow spacing is about 15cm, plant spacing is about 10cm, sowing amount is about 125g/m2, seedling yield is 50-60 plants /m2, topdressing at seedling stage is 1-2 times, and sulfuric acid is applied 7.5-1m2.
Second, cutting seedlings, generally the cutting effect is the best when the new branches are semi-lignified. When the branch is semi-lignified, it has the strongest activity and rooting ability, which is the best cutting time. The cutting period of flat-headed wood in Northeast China is from June to mid-July. Before cutting, it can be treated with 70mg/kg butyric acid powder or 100mg/kg tea acetic acid solution for 24 hours, and it can take root 20 ~ 25 days after cutting, and the survival rate can reach 65%.
3. Tissue culture and seedling raising: Tissue culture and seedling raising is a method of rapid propagation of flatwood. After surface disinfection and sterilization, the new buds were cut into small pieces of 0.5cm, and the stem segments with axillary buds were cultured in MS medium containing 1mg/L6-BA and 0.5mg/LNAA. Stem segments with axillary buds produce light yellow loose callus on the stem nodes at the base of axillary buds for 2-3 weeks. After 4-5 weeks of culture, when the callus grows to about 0.5 cm, the callus is cut off and transferred to the medium of 1 mg /L6-BA and 0.05-0.1mg /LNAA for culture. After 3 ~ 4 weeks, the original loose callus surface differentiated and formed many tumor-like callus. The tumor-like callus gradually differentiated into buds or clustered buds, and continued to be cultured in the original medium, and the differentiated buds or clustered buds grew slowly. For example, if the buds and part of the calli at the base are transferred to the medium containing 0.5mg/L6-BA and 0. 1mg/LNAA respectively, the differentiated buds will be rapidly elongated, and the seedlings will grow to 2-3 cm high in about 2 weeks, and the seedlings will be transferred to half.