Studies On Tissue Culture Of Masson Pine

Mature zygotic embryos of masson pine provenience from Guangdong xinyi and Guangxi tongmian were cultured as the initiation explants in order to investigate the procedures of induction, differentiation, elongation and roots development. The highest differentiation rate of adventitious buds was 100% on the DCR medium supplementd with 0.5mg/L BA, 0.1mg/L NAA. After culturing on a hormone-free GD medium for elongation , adventitious buds were transferred on the 1/2GD rooting medium with 2mg/L IBA, 0.05mg/L BA. The highest rooting rate was 78.8%.With the mature zygotic embryos of masson pine as the explants, the inducement of adventitious buds generally initiate on the cotyledon or the upper hypocotyls. The more ideal result of inducement attained on the medium containing cytokinin and auxin comparing with the medium with cytokinin only.The proper concentration of auxin(NAA, IBA) is 0.05-0. Img/L. It is necessary for the differentation of high quality adventitious buds that they are turn into the medium with lower concentration of hormones.Induction and multiplication of dormant buds and establishment of cuvette clone take aseptic seedlings from mature zygotic embryos of masson pine as explants. KT has superior effect for the induction of the dormant buds among other cytokinins. The best induction medium is DCR or GD medium supplemented with Img/L KT and 0.2mg/L BA, and differentiation rate of the dormant buds is 95.7 and 94.5%, respectively. The following steps of rooting ablity experiment and plantlet transplant are similar to the processes of the adventitious buds'.We found that it is comparative easy to induce dedifferentiation of zygotic embryos of masson pine.and it's no apparent differences among the various meium in a certain extentHowever, the medium with low hormone content has the superior results in the following culture process.How to prevent the callus turned brown is the basis of solution of the key problems of embryogenesis that preservation the embryogenic callus and promoting germination of the somatic embryo.A nicer framework for micropropagation as mentioned above was established, and then the geneic transformation by means of somatic embryogenesis of the superior clones of masson pine can be conducted also.