Studies On Tissue Culture And Adventitious Root Mechanism Of Rhodoleia Championii Hook.F.

Rhodoleia championii Hook. f. belongs to the genus Rhodoleia in the family Hamamelidace. With high and straight trunk, extended branches, beautiful posture, green leaves in four seasons and large bell-shaped deep red flowers, It has high exploited value in ornamental, ecological protection, timber and so on. However there are not so many studies investigating the breeding and tissue culture of R.championii. The objective of this study was to breed the R.championii and examine the mechanism of its adventitious root, using seed as explants. The results are as follows:(1) Sterile system was constructed quickly by using seeds as explants, which are sterilized in 0.1% HgCl2 for 10-12 min and then inoculated in WPM+6-BA 0.5 mg L-1+AC 1.0 gL-1 medium.(2) The best multiplication medium was WPM+6-BA 0.50 mg.L-1+NAA 0.05 mg.L-1.The difference of subculture and proliferation abilities was extremely remarkable among the three genotypes, in which the "d" of proliferation abilities is best, followed by "1" and "f".(3) The best growth regulators sorts and concentrations for sterile seedlings rooting was IAA 2.0 mg.L-1. Sucroses with various concentrations could not influence rootings. Additionally, activated carbon could not increase rooting rate and coefficient, but benefit for sound seedlings.(4) The best treatment method for microshoots cutting of R. championii was IBA 50 mg.L-1 for 60 min and IBA 200 mg.L-1 for 30 min.The extremely remarkable difference is in the mean number of roots, but not in the rooting rate. Among them, genotype "1" were highr than genotype"f".(5) The research of anatomy was conducted on the development of adventitious root of R. championii. The adventitious root primordia belongs to the type of the induced primordium, which originating from the vascular cambium.(6) In the development of adventitious root of R. championii, using exogenous auxin could increase the cotent of IAA and GA,decrease the content of ABA and ZR, increase IAA/ABA and IAA/ZR ratio Which benefit for the adventitious root formation and elongation.(7) Using exogenous auxin could increase the POD,PPO activity and reduce the IAAO activity of microcuttings. Which promote the adventitious root formation.