PLANT REGENERATION VIA SOMATIC EMBRYOGENESIS FROM IMMATURE COTYLEDONS IN SOYBEAN (GLYCINE MAX (L.) MERRILL)

Abstract

Three varieties of soybean DT12, VX93 (Vietnamese varieties) and Thome (American variety) were used to establish a plant regeneration system via embryogenesis from immature cotyledons explants. Firstly, cotyledons of immature seeds collected from different stages at 5, 10, 15 and 20 days after flowering were cultured On somatic embryo induction medium containing the basic MS supplemented B5 vitamine, 30 mgll sucrose, 2,4 D with different doses 20 mg/l, 30 mg/l, 40 mg/l and solidified with agar. The induced embryos with solid bright green fonn were transferred to the new somatic embryo induction medium every 4 weeks for further development. Secondly, matured embryos were then transferred to somatic embryo germination medium including the basic MS, B5 vitamine supplemented 60 gil maltose and 2 gil actived chacoal for somatic embryo germination. Finally, germinated embryos were transferred to medium including the basic MS, B5 vitamine, 30 gil sucrose for shoot and root elongation. In this research, embryos were only induced from DT12, but not from VX93. The proper stages for immature seeds for effective initiation of embryos were the seeds of 10 • 15 days after flowering. The efficiency of regeneration of DT12 variety was 39% and the average number of embryos were 7.5 per explants.