Study On Tetraploid Induction In Paulownia Catalpifolia And Paulownia Kawakamii And In Vitro Plant Regeneration

Paulownia is a fast-growing tree produced high quality timber and green trees,Which play an impotant role in improving the ecological environment and the living standards of farmers.But the issues of paulownia witches’ broom,low rod crested affect the growth of paulownia To further optimize the characteristics of Paulownia,expand the germplasm resources,create new varieties of forest,in this study,using P.catalpifolia and P.kawakamii diploid as experimental materials,induced by colchicines to obtain Tetraloid plant of Paulownia.Establishment of two specises of Paulownia in vitro plant regeneration system,in order to cultivate new varieties of Paulownia for researching foundation.After a lot of research,The conclusions are as follows:(1)Get two kinds of tetraploid paulownia.Tetraploid P.catalpifolia in pre-culture 6 d,Colchicine concentration of 30mg · L-1,Soaking in the induction time of 48 h to reach the maximum rate,the maximum induction rate of 5.83%.Tetraploid P.kawakamii in pre-culture 6 d,Colchicines’s concentration of 10mg · L-1,Soaking in the induction time of 48 h to reach the maximum rate,the maximum induction rate was 6.9%.(2)Identification of tetraploid Paulownia.Chromosome number of the three kinds of tetraploidy plant is 80 and that of diploid plant Was 40.Results of the flow cyomctric analysis showed the tetraploid paulownia DNA content is twice higher than the diploid paulownia.(3)Difference between two kinds of tetraploid and diploid paulownia’s morphological and physiological indicators.Leaves of tetraploid seedlings were larger,thicker and greener.The stomata size of tetraploid plants were significantly larger than those of diploid ones.while the stomatal density decreased.In addtion,chlorophyll increased,SOD activity,soluble sugar,soluble protein content increased,and POD reduced.After the membership function of the fuzzy mathematics comprehensive evaluation,the results is that the resistance of P.kawakamii is stronger than P.catalpifolia,the resistance of tetraploid P.kawakamii is the strongest,the resistance of diploid P.catalpifolia is the weakest.(4)Screened out the best two specises of tetraploid Paulownia regeneration system growth regulator combinations.The Best explants of tetraploid P.catalpifolia and P.kawakamii are leaves.Two specises of tetraploid Paulownia’s leaves optimum medium for callus induction were MS+0.3NAA+14BA and MS+0.1NAA+14BA、the optimal medium of bud induction were MS+0.3NAA+16BA and MS+0.3NAA+16B A、the optimal medium of roots induced were 1/2 MS and1/2MS+0.1NAA.