[Improvement of microspores culture techniques in Brassica napus.L]

The application of microspore culture technique was restricted because of its low frequency of embryogenesis and chromosome doubling. Two methods of enhancing the frequency of embryogenesis were employed in the study,namely,activated charcoal treatment in NLN-13 media and 6-BA treatment in NLN-16 media. The treatment with 0.05% activated charcoal produced 24 embryos per plate,which increased 1.7 embryos per plate, as compared with the treatment without activated charcoal. However,the analysis of T-test showed that it was not significant. After adding 0.1 mg/L 6-BA in NLN-16 media, the frequency of embryogeny was 38.3 embryos per plate,and it was 26 embryos more per plate than that of CK. Analysis of T-test is significant. This indicates that 6-BA promotes embryogeny in microspore culture. Adding 50 mg/L colchicines in NLN-16 media,the doubling frequency was 67.6%. The plantlets transplanted into field with two methods of light-covered net and plastic films were investigated. A survival rate of 87.6% was obtained using light-covered method whereas 57.7% survived using plastic film method.