用RFLP标记分析甘蓝型油菜的遗传多样性

以甘蓝型油菜的２８个基因组探针和两种限制性内切酶对包括４６个中国品种、９个欧洲品种在内的５９个甘蓝型油菜品种（系）的ＲＦＬＰ标记进行了分析。在放射自显影胶片上，共检测到４１０条具多态性的分子杂交带，表明甘蓝型油菜中存在着极为丰富的遗传变异。聚类分析结果表明，在相似性为４５％的水平上，可把中国甘蓝型油菜划分为６组：胜利油菜组、跃进油菜组、中油８２１组、远缘种质组、优质油菜组和变异不详组。欧洲冬油菜与以上６组存在着较显著的遗传距离。主成分分析的结果与上述分组较为一致。以上结果表明，对于扩大中国甘蓝型油菜的遗传基础，欧洲冬油菜无疑是一个重要的种质资源。另一方面，用典型的中国甘蓝型油菜与欧洲冬油菜配制的杂交种，较易产生强大的杂种优势。从对已进行了染色体定位的６１条放射自显影带的分析看，无论是上述分组内，还是分组间，ＲＦＬＰ的相对差异均主要表现在Ａ基因组中。讨论了致使Ａ基因组遗传变异较大的可能因素。

Genetic Diversity of Brassica napus Detected with RFLP Markers

RFLP patterns were analyzed from 59 cultivars of Brassica napus,including 46 Chinese and 9 European accessions,using 28 genomic probes of Brassica and 2 restriction enzymes.410 polymorphic bands were detected indicating that there was considerable genetic variation within the sample of B.napus cultivars.According to the average similarity analysis,the Chinese accessions could be divided into 6 groups,i.e.,Shenliyoucai,Yuejinyoucai,Zhongyou 821,Distant germplasm aggressive,Canola and undetermined variation groups.The European group of winter cultivar was strongly distinguished from Chinese groups.The division was also observed in principal coordinate analysis.In view of the obvious genetic differences,the European winter-typed rapeseed would be an important germplasm resources fro enriching the genetic background of Chinese rapeseed,and vice rersa.On the other hand a strong heterosis might be explored from the hybrids between the two types of rapeseeds.61 bands,which had been located on particular chromosomes,were used to explore the relative differences of RFLP between cultivars.It was shown that no matter the cultivar pair came from the same group or not,the genic variation mainly appeared at genome A.The possible factors responsible for the variation occurred at A genome are discussed.