Studies On Ecological-biological Characteristics And Asexual Reproduction Of Macropanax Rosthorniiby

Macropanax rosthornii is a wild spicies, which belongs to Araliaceae family, mainly distributed in Gansu, Sichuan, Guizhou, Guangxi, Hubei, Jiangxi, Guangdong, Fujian, Zhejiang, etc. But its distribution is very narrow in each producing area. Macropanax rosthornii is of higher potential value in medicine and ornament, but has not been developed and utilized. The habitat of Macropanax rosthornii and its community characteristics were investigated and discussed for the first time. Based on the biological and ecological characteristics of Macropanax rosthornii, the asexual-reproduction was also studied. The research on wild Macropanax rosthornii provides a scientific basis and ways for the introduction and domestication. It is significant for the wild plants'preotection and exploitation.From the habitat in Shironghe District of Yongshun county, it indicated that this area belongs to the subtropical mountain humid climate, distinctive seasons, plentiful sunshine and rainfall, warm and humid climate, and it is characterised as typical cubic climates, the microclimate effect is significant. The soil is yellow brown soil with higher fertility. The withered fallen leaves of forest land are deep on storey. Macropanax rosthornii is suitable to grow in coniferous forest with canopy density lower (about 0.3), but it is fragmentary in the coniferous broad-leaved mixed forest. The type of the community is the natural secondary forest. Major is coniferous broad-leaved mixed forest, and there are also a few coniferous forest. The main dominant species in community is Cunninghamia lanceolata. The subdominant species in community is Macropanax rosthornii.From the tissue culture experiment, it indicated that the best result of sterilizing agents is 0.1% HgCl2 (4 min 30 s); the contaminated rate was lower than 15%; WPM and B5 substrates were suitable for the tissue culture of Macropanax rosthornii; the buds were better for inducing callus. The medium B5+NAA 2.0 mg·L-1+6-BA 1.0 mg·L-1 and WPM+NAA 2.0 mg·L-1+6-BA 2.0 mg·L-1 was the optimum medium for inducing callus and the rate got to 68% and 56%; the sucrose concentration on the callus induction has significant effect. If sucrose concentration was too low, the inadequate nutrition in the medium led to explant death or inhibiting the formation of callus; the optimum medium for proliferation is B5+NAA 0.5mg·L-1+6-BA 4.0 mg·L-1. The embryoid occurred from the callus proliferation.The asexual experiment result showed that the survival rate of Macropanax rosthornii cutting propagation was low; with the appropriate growth regulators treatment, rooting rate increased. The stroma had great influence on the twigs to root and the best choice of the stroma for the Macropanax rosthornii was perlite, but the perlite can be replaced by the red soil. From the experiment, the plant growth regulators such as ABT, BA and NAA of were fit to the cutting with the concentration 100～500 mg·L-1. Good drainage prevented from the rot of the adventitious root from cutting.