Study On High-efficiency Germination And In Vitro Propagation Of Idesia Polycarpa Maxim

Idesia polycarpa Maxim, hydnocarpus genera deciduous tree, is a promising energy tree species with important application prospects. It survives on marginal landand grow in the area of annual rainfall800～2000mm. Idesia polycarpa is also an excellent returning tree with straight trunk, lush flowers and bright red fruit. The fruit and seeds are rich in fat (especially linoleic acid) with oil content as high as36%. As an important woody oil species, it can be used as biodiesel, edible oil, industrial oil, and be processed for health foods and drugs. However, the poor and slow germination under natural conditions and scanty asexual reproduction study affect its popularization and application. In this paper, a high-efficiency germination method was established, and the in vitro rapid propagation was also studied. The results are as follows:1. The influence factors of seed sterilization and germination, different disinfectant reagent (HgCl2、NaCIO) and methods (H2SO4, H2O2, ultrasonic treatment, cold stratification) were studied. The results showed that the treatment with2min70%ethanol and5min0.1%HgCl2could reduce the contamination rate to2%,and combining with10min30%hydrogen peroxide could get90%germination rate within15days. The treatment with10min20%hydrogen peroxide in combination with cold stratification could get78%germination rate within22days.2. The callus induction parameters were studied using stem sections, leaves, petiole and sterile hypocotyls of Idesia polycarpa as explants. The results showed that the suitable disinfection treatments were15s70%ethanol+60s0.1%HgCl2for leaves,30s70%ethanol+60s0.1%HgCl2for petiole, lmin70%ethanol+3min0.1%HgCl2for stem sections. The explants survival rate was more than95%. MS+NAA1.0mg/L is the optimum medium for leaves callus induction with induction rate of37.9%, and the proper medium for callus proliferation is MS+NAA0.5mg/L. The optimum medium for stem sections, petiole, sterile hypocotyls callus induction and proliferation was MS+6-BA0.5mg/L+NAA1.0mg/L, and the induction rate was more than95%. But the calli differentiation was failed. 3. The rapid propagation system was established with stem sections as explant in the following experimrnt. The results showed that MS+6-BA0.5mg/L is the optimum medium for adventitious bud induction and multiplication. The adventitious bud induction rate was96.7%. The proper elongation medium is1/2MS+6-BA0.1mg/L. The axillary buds were rooted on1/2MS medium supplemented with IB A0.5mg/L with rooting rate of94.4%, and the average root number was5.6. The most proper matrix for domestication and transplant is the mixture of flower fertilizer and vermiculite. Ihe seedling survival rate was up to65.85%.