Optimization Of Tissue Culture Regeneration System And Polyploidy Induction Of Eucommia Ulmoide Oliv

Eucommia ulmoides oliv. is a multipurpose tree species,which belongs to Eucommia,Eucommia oliv..It is worth exploring. The same as other cultivated tree species, the breeding of Eucommia ulmoides oliv. is an extremely important basic work in the exploitation of resource. Polyploid plants have many advantages such as gigantic organs and strong stress resistance,so polyploid breeding is one of important ways of breeding.Colchicine is one of chemical substances which are used to polyploid inducement. There are many treatment materials and methods ,but the method of chromosome doubling using mature seeds as material has been applied widely. In the recent years,with the developing of plant tissue culture techunique,artificial chromosome doubling in vitro is an efficient approach to produce polyploidy plants.If artificial chromosome doubling in vitro is used, a high-efficient tissue culture system must be established. In the study,based on previous research results, regeneration system was optimized, and using mature seeds as material the technologies of polyploid inducement and identification was studied . The main results are as follows:1. In vitro propagation system was optimized: Optimization of regeneration system was studied by using tender leaves as explant. The results showed that : MS+NAA1.5 mg/L +6-BA2.0 mg/L had the best effects on induced to callus,and the rate of callus formation was 95%; the best medium of callus growth is MS+NAA1.0 mg/L +6-BA2.0 mg/L ,and good result archived in 98.5% ; the suitable medium for bud formation is MS medium added NAA0.5 mg/L, 6-BA2.0mg/L,and buds differentiation rate was 40%;the optimum media for rooting is 1/2MS+IBA1.5mg/L with 92.5% rooting ratio.2. Polyploidys induction: the best method for polyploids induction is soaking seeds in 0.2% liquid colchicum for about 48h. The highest induction ratio is about 13%. Seeds soaked with colchicum and then cultured in medium would have a higher polyploids induction ratio than cultured directly in medium with colchicum. Total 43 polyploids individuals were obtained in this study.By observing plant stomata, it shows us the stomas are larger than diploid, but the tetraploid density is smaller. The pore size and density could be used as a reliable indirect index in Eucommia ulmoides Oliv. polyploids appraisal.