Study On Induced PLB And Seedling Factor For The Root Of Cymbiuidm Hybridum

Cymbidium hybridum is a kind of highly ornamental Orchidaceae plant. Because of its long cultivation period and propgated by traditional method of offshoots which has low reproduction rate,it is difficult to meet the needs of large scale production.With the development of modern biological technology, tissue culture could be gradually applied to it is propagation,which could greatly increase propagation coefficient and speed.It not only solves the problem of market demand,but also provide scientific basis for the actual production.This paper takes the Cymbidium roots as explants to establish aseptic system, then makes orthogonal experiment and multiple comparisons through different growth hormone in order to study how the hybridization Cymbidium roots inducing PLB, PLB proliferation, germination, seedling and rooting. The results are as follows:(1)From the analysis and comparison,the hybridization Cymbidium roots was sensitive to75%alcohol, NaCIO and0.1%HgCl2solution, and75%alcohol disinfection15s is proved to be the optional method.This method has the lowest contamination rate, browning rate and the highest survival rate with32.34%,23.43%and83.7%respectively.(2) The best medium for the inducing shoots from PLB was MS+6-BA (1.5mg-L-1)+NAA (0.5mg-L-1)+VC with largest induced PLB roots number and average induction rate of up to87.2%in25days.In this experiment, the time and induction rate are superior to the reports on indced PLB root.The root explants enhances the induction rate, ahead inducing time, shorten the breeding cycle, and reduces the cost greatly.(3) The best multiplication medium of PLBs was MS+6-BA (2.0mg·L-1)+NAA (0.1mg-L-1)+VC, corm piece proliferate optimum, the average induction rate up to532%.(4) The best medium for seedling differentiation was MS+6-BA (1.0mg-L-1)+NAA (0.8mg·L-1)+VC, and seedlings grow strongly with dark green leaves, some may continue to became the corms.(5)As showed in this strong seedling test,, add the appropriate hormone combination and additive in MS basal medium can promotes strong seedlings. Ascorbic acid has more effective on strong seedlings than activated carbon,activated carbon tetto has a certain extent effect on strong seedlings but less significant than ascorbic acid.The best medium for promoting seedling was MS+6-BA (0.6mg·L-1)+NAA (0.2mg·L-1)+VC (50mg·L-1), and the plant grow strongly with stronger root,longer and larger leave, wider stem.(6) The best medium for promoting rooting was1/2MS+NAA (0.6mg·L-1)+VC. The plant grow strongly with stronger root,longer and larger leave, wider stem.Its average root length can up to4.4cm. (7)Removed seedlings from tissue culture bottles to be transplanted,the results show that the seedlings in VC50mg·L-1additive are stronger than without additives, the best transplanting medium is coconut husk mixed perlite with1:1,and the survival rate arrive to the peak of96%with stronger seedlings and dark green leaves in the later30days.