Research On Tissue Culture And Changes Of Endogenous Hormones In Rooting Culture Of Cercidiphyllum Japonicum Sieb.Et Zucc

Cercidiphyllum japonicum Sieb. et Zucc with high scientific research medicinal and ornamental values is a kind of precious and endangered plant of the national second-grade protection in China. In present, the propagations mostly are cottage breeding grafting and seed propagation. But, these propagations are low productivity and long multiplication cycle, while the quantity of plantlet is far from the needs of offorstation and scientific researches.In this paper, we tested the physiological indexes of seeds which were influenced by temperature light and chemical reagents to select the best codition of germination of Cercidiphyllum japonicum Sieb. et Zucc. The results of physiological indexes included that the1000-seed weight was0.721g and the the seed vigor was42.44%in natural condition. Although the seeds were soaked in the KT GA3and10%PEG solution ahead of time, the germinations were only37.12%36.31%and31.01%respectively. This showed that the embryo of the seeds having inhibitory substance to lead afterripening when lower production with seeds. To enhance the ability of rapid propogation of Cercidiphyllum japonicum Sieb. et Zucc, we used the technique of plant tissue culture and established rapid propogation system.We established and optimized the regeneration system with axillary buds and the stems of seeding seeds by using the technique of plant tissue culture. The resultes represented below:The best antiseptic method of asepetic materials was that the explants were sterilized with0.1%HgCl2for12min and6min.respectively after disinfected by70%etanol for30s, and the survival rates respectively reached23.33%and22.22%in1/2MS medium.The best proliferation medium of shoot clums is MS+6-BA1.0mg/L+NAA0.5mg/L+GA32.0mg/L+sugar30g/L+agar7g/L+pH6.0, with the highest multiplication rate of6.33. The optimized rooting culture medium is1/2MS+IBA2.0mg/L+NAA0.5mg/L+6-BA0.5mg/L+AC2.0g/L+sugar30g/L+agar7g/L+pH6.0, while the rooting rate root number and the root length is. respectively80%5.5and6.51cm. A positive correlation is found between rooting and the content of IAA and the value of IAA/ABA using high performance liquid chromatography in rooting culture The optium inducing callu medium by leaf and stem is MS+2,4-D2.0mg/L+6-BA0.1mg/L+sugar30g/L+agar7g/L+pH6.0, and the callus induction is61.11%and77.78%in darkness.