Study On The Key Techniques Of Tissue Culture In Rhododendron Delavayi

Rhododendron delavayi is a perennial ever-green bush in the rhododendron family, and is a precious woody flower. It naturely grows in the jungle of the western of China, and is introduced into and domesticated by some countries such as Germany and Belgium. Nowadays it already has been a high valuable ornamental,and has had a bright foreground on flower market recently. Sticking and reproducting and graft are the conventional breeding ways, but precious woody flowers not only have difficulty in rooting, but also are confined by the season and the material of female parent, which are inbenefical to commercialized breeding. With the development of the technology of woody plant tissue culture, the tube seeding of rhododendron is obtained, espicially the study on woody plant medium and Read medium which are efficient to the tissue culture of the rhododendron family.There are many people who studying on propagatating rhododendron with tissue culture, and obtained great achievement. But some problems such as the explants browning, high vitrificating rate and hardy rooting are usually existent in tissue culture. According this, the the micpropagation procedure of rhododendron had been researched, including the establishment of selecting explant, initial culture, subculture breeding, stronger nurslings breeding, rooting breeding, transplantion breeding, preventing from browning and vitrificating, which are advantageous to the production of factory of rhododendron, and could make the seedling technique of rhododendron to exceed the previous new step.The efficient method was explored abourt Rhododendron delavayi in vitro multiplication. The stems with buds of Rhododendron delavayi were as explants to establish the technich system of tissue culture. Multydesign and multyanalysis was used to fing out the best composition of medium and the best proceeding of culturing , and the effective measures to prevent the browning and vitrification of explants. The results were as follow :1. Temperature for culture: Day 25±2℃,Night 23±2℃.14 to 16 hours illumination every day, and about 1600 to 2000 lx illumination intensity. The pH of medium was adjusted to 5.0～5.3.2. Selecting explant: The stem with buds as explant is effect to plantlet,and the bottom axillarry buds is effect to the 2～3 year odd.3. The best initiation medium was Read+ZT1.0mg/L+IBA0.05mg/L, for a week dark treatment. After a month culture, the frenquency of initiation could reach 69.0%4. The multiplication of shoot clump: Read+ZT0.6mg/L+IBA0.05 mg/L+0.3g/L was the best medium.After 80 days culture, the increasing coeffecient was 6.12.5. Stronger nurslings culture: The Read medium with NAA0.2mg/L,AC 0.3g/L and sugar 25g/L could strong nurslings effetively.6. Rooting curture: The Read with NAA 1.5 mg/L, IBA 0.5mg/L, AC 0.3g/L and sugar 15g/L...