The effect of plant growth regulator on embryogenic tissue induction in four pine species

In this survey, the possibility of somatic embryogenesis in four different pine species was studied using different compositions of plant growth regulator. The embryogenic tissue induction phase was performed using mature zygotic embryo explant, culture medium DCR and using different levels of plant growth regulator in Pinus brutia, P. nigra, P. radiata and P. sylvestris species. The experiment was done through a completely randomized design with a simple factorial arrangement. Embryogenic tissue was measured in two phase, 30 and 40 days after the initial culture. After sterilizing of seeds kept at 4°C, and removing their coats, zygotic embryo was separated from megagametophyte and put into the Petri dish containing solid tissue culture. All the Petri dishes were maintained in darkness at 25°C. After 2 weeks the first signs of embryogenic tissue induction were observed. The results showed the significant effect of composition of plant growth regulator and specie on the amount of embryogenic tissue induction and the best result was obtained from P. brutia in hormon composition of 10µM 2,4-D+5µM BA. In order to proliferation of embryogenic tissues, subculture of tissues was performed every two weeks in new culture medium for six weeks. Finally, in order to maturation of somatic embryo from embryogenic tissue, the segments of embryogenic tissue with 5×5 mm dimensions were transferred to DCR culture medium. After two months, although quasi-embryo and abnormal structures got seen but the production of complete embryo from embryogenic tissue was unsuccessful and transition from preembryony phase and conversion to embryo with developed cotyledons failed.