^(60)Co γ辐射兰花春剑隆昌素根状茎分化苗的ISSR分析

ISSR Analysis of Cymbidium ‘longchangsu' Seedlings in Vitro and Mutagenic Progenies by Radiation

以兰花春剑隆昌素品种为材料,用不同剂量60Co γ射线辐照处理其根状茎,研究辐照诱变技术对兰花根状茎组织培养成活率及分化率的影响,并用ISSR分子标记技术检测春剑隆昌素组培苗辐射诱变前后引起的DNA变异情况。结果表明:10 Gy辐射处理后的根状茎分化苗率为93.2%,20Gy辐射处理后根状茎分化苗率为54.4%,而40Gy和60Gy剂量处理后的根状茎几乎全部死亡。主要变异性状是叶色失绿变淡。通过对春剑隆昌素辐射后代形态变异株的ISSR基因检测,发现经过30多年继代培养的春剑隆昌素组培苗的变异率为6%,而辐射诱变后代的变异率为18%。说明经过60Co γ辐射诱变的根状茎所获得的变异比组织培养所获得变异高。可疑突变株和对照组在15个ISSR引物扩增结果中并未出现明显的差异,ISSR分子标记结果与植株表现出的形态变化之间可能并不存在一一对应关系。

Inter-Simple Sequence Repeat（ISSR） molecular markers were used to analyze the Cymbidium ‘longchangsu’ seedlings in vitro, mutagenic progenies and the leaf shape mutants by 60Co γ rays. Results showed that the differentiation rate of the radiated rhizomes by 10Gy and 20Gy were 93.2% and 54.4%,respectively. The rhizomes radiated by 40Gy and 60Gy were all died. The mutation rates of seedlings by repeatedly subcultured in vitro were 6% and the mutagenic progenies by radiation were 18%.It is indicated that the mutagenic rates caused by radiation is higher than that by tissue culture. No significant differences were observed between suspicious mutants and the control after the gene detection of the leaf shape mutants. It suggests that,maybe,there were not significant correlation between ISSR results and the morphological changes.