Study On In Vitro Plant Regeneration Of Catalpa Bungei And Induction Regeneration Of Autotetraploid Of Catalp Bungei

Catalpa bungei is precious tree species in China, can be used in timber production and ornamental cultivation and other way. The widely cultivation of Catalpa bungei not only help to improve ecological environment in China, also can ease the shortage of wood. And has important economic value on the development of forest products exploitation industry. With the rapid development of modern biotechnology, polyploidy cultivation has become a new and innovative way in tree breeding resources, and also gave foundation in polyploidy breeding of Catalpa bungei.Catalpa bungei seeds are used as experimental material in this experiment, establish the Catalpa bungei regeneration system in vitro with completely random method, Catalpa bungei seeds are treated with colchicines in a variety of methods to induce tetraploid of Catalpa bungei. The main conclusions as follows:1,The regeneration conditions of Catalpa bungei in vitro were studied with Catalpa bungei leaves and stems. The result shows that the best explants are stem. The induction media of Catalpa bungei stems callus were MS +0.3 mg·L-1 IBA +7 mg·L-1BA. The best callus induction media of Catalpa bungei stem buds were MS +0.3 mg·L-1 IBA +5mg·L-1 BA. Clustered buds induction were MS +0.1 mg·L-1 NAA +12 mg·L-1 BA. Root induction were and 1/2MS+0.5 mg·L-1 NAA2,In the induction of tetraploid Catalpa bungei using seeds in the solid medium with colchicine, in the coichicine concentration 40mg·L-1,the highest induction rate of tetraploid Catalpa bungei are 10%, the highest rate of mixoploid are 81.7%. Concentration of colchicine in solid medium makes significant effect on the induction tetraploid Catalpa bungei using seed.3,In the induction tetraploid Catalpa bungei using Drip method, Concentration of the colchicine from 40mg·L-1 to 300 mg·L-1,7 combination treatment were designed, mixoploid appeared in five, and 40 mg·L-1 did not induced mixoploid. other 4 combination appeared mixoploid plants, mixoploid rate are 25-45%. Tetraploid plants were not detected. In the induction of tetraploid Catalpa bungei using different processing time of colchicine immersion method. the colchicine concentration are 0-120 mg·L-1,13 levels, and 65 combinations.Mixoploid appeared in 52 combinations of 65, induction rates of mixoploid range from 1.7 to 58.3%. Tetraploid plants were not detected. In the induction of Catalpa bungei tetraploid using the same processing time of colchicine immersion method. The colchicine concentration are 0-120 mg·L-1,13 levels, and 52 combinations. Mixoploid plants appeared 48 combinations. Induction rates of mixoploid range from 23.3 to 60%. Tetraploid plants were not detected. Titration and seed soaking method were not induced tetraploid Catalpa bungei.4,The results of the flow cyometric analysis showed the tetraploid plant present twice higher DNA content as the diploid plant.5,Leaves of tetraploid were larger, thicker and greener, zigzag on the board significanth denser. The stomata size of tetraploid plants were significantly larger than those of diploid, while the frequency of stomata were reduced significantly.