Breeding Technology Research in Rare and Endangered Species of Cercidiphyllum
|School||Central South University of Forestry Science and Technology|
|Keywords||Cercidiphyllum japonicum Habitats Endangered Breeding technology|
Cercidiphyllum (Cercidiphyllum japonicum Sieb. Et Zucc.) is a single species of plant in cercidiphyllaceae of Cercidiphyllum, for the national Ⅱ level specially pr-otected wild plants. Cercidiphyllum is one of the famous formation of tree species, it has high utility value in material, medicine and chemical industry and other fiel-ds, widely cultivation as ornamental tree species by the worldwide. But for many reasons, Cercidiphyllum populations have existing rare and endangered in the state. Therefore, this study made a preliminary discussion about breeding technology of Cercidiphyllum’s community. The results were as follows:(1)Through the survey found that distribution of Cercidiphyllum is single,dioe-cious, tiny seed, habitats is worse, pollination fertilization is difficult, no natural up-date and serious man-made destruction leading to endangered of Cercidiphyllum.The refore, puts forward protection measures which is the in-situ conservation, ex-situ conservation, speed up the research of artificial breeding and cultivating techniques.(2)The seed of Cercidiphyllum is tiny seeds, the bibulous rate of seed is high er, could reach350%-400%, provide enough water. When grow seedlings, ensure the seeds could germinate. Thousand seed weight of Cercidiphyllum is1.34375g. The nutritious material of seeds are less, so the seed can’t provide enough energy for germinate. With Other causes, lead to germinating rate of seed of Cercidiphyllu m is low in the natural conditions.(3)Cutting with hard wood of Cercidiphyllum, choose three different concentra-tion of Hormones (Hormodin) to treat the hard wood. The effect of different conce ntration of Hormones in the rooting rate, the average length of root is no significa ntin. But with the increase of the concentration of the hormone, rooting rate and the average length of cuttings had a trend of increase. Effect of different concentra-ion of Hormones in the number of rooting cuttings which is treated by Hormodin8000mg/L hormone is a significant, he average number of rooting is9.71, in this case, rooting rate is the highest in the three kinds of concentration of Hormones, is54.84%.Under the same treatment with hormone, effect of different matrix in the root- ing rate, the average length of root of Cercidiphyllum is extremely difference which is treated by the matrix of perlite+plant ash (3:1), the effect of different matrix in the number of rooting cuttings is no significantin, rooting rate is86.67%, and the average length of root is6.08cm. Other matrix is not significant effect.(4)Use the leaves of Cercidiphyllum on training the callus induction, the best sterilization time is75%alcohol30s+0.1%HgCl29min. Steep the explant in liquor of0.2%Na2S2O3for20-30min, can effective prevention browning, and ma-ke browning rate cut to7.8%. Train the callus induction with the leaves of Cercid-iphyllum, MS+6-BA2.0mg/L+NAA0.1mg/L+2,4-D1.0mg/L is the best media for callus induction, rate of induction reached54.43%. Subculture with callus of leaves is unsatisfactory. Differentiated culture with callus of leaves can’t grow th e adventitious bud.Use the stem with axillary bud of Cercidiphyllum on initiation culture, the be-st sterilization time is75%alcohol1min+0.1%HgCl212min. MS+6-BA1.0mg/L+NAA0.2mg/L is the best initiation culture matrix, the rate of initiation re-ached91.07%. Subculture the stem with axillary bud in the best initiation culture matrix is unsatisfactory, the multiplication coefficient of cluster buds is just0.31.