亚麻种质资源遗传多样性与亲缘关系的AFLP分析

Genetic Diversity and Relationship of Flax Germplasm as Revealed by AFLP Analysis

选取18个中国品种和67份来自世界各地的亚麻材料(包括油用亚麻、农家种和野生种),采用7对引物通过扩增片段长度多态性(AFLP)分子标记分析,获得168个具有多态性位点,平均每对引物可扩增出24条带。利用NTSYS2.1采用非加权配对算术平均法(UPGMA)聚类分析,计算遗传距离和构建遗传系统进化树。结果显示,85份材料在遗传相似系数0.53处分为4类,可以将栽培种和3个野生种区分开来;在遗传相似系数0.67处可以将纤维亚麻划为1类,而绝大多数油用亚麻分成4类,油用亚麻的遗传多样性远高于纤维亚麻;国产纤维亚麻中黑字号品种相似度极高,遗传背景狭窄,而双字号品种多样性稍好。还证明Linum bienne与亚麻栽培种(Linum usitatissimum L.)关系密切,并支持纤维亚麻来自油用亚麻的假说。

Flax （linum usitatissimum） is one of the major fibre and oil yielding crops. AFLP is very useful molecular marker for a number of plant species. To reveal the genetic diversity and find ways to broaden the genetic background of Chinese fibre flax varieties, we analyzed 18 Chinese fibre flax cultivars and other 67 accessions （including linseed, landrace and wild species） from different countries in the world by using AFLP marker. In total, 168 polymorphic alleles were detected with seven pairs of AFLP primer. For each pair of primer, 24 alleles on the average was detected in all accessions. Unweighted pair-group method with arithmetical averages （UPGMA） cluster analysis was used to estimate the genetic distances and to construct a dendrogram by NTSYS 2.1. The results showed that all 85 accessions were classified into four groups at 0.53 of similarity coefficient, which distinguish the varieties of flax （Linum usitatissimum） from three wild flax species. All varieties of flax were classified into five sub-groups （all fibre flax accessions were in one sub-group and the most of linseed accessions divided into other four sub-groups） at 0.67, indicating linseed possessed genetic basis broader than the fibre flax. In Chinese fibre flax varieties, Heiya cultivars had high genetic similarity, and its genetic basis was narrower than that of Shuangya variety. The results also showed that there were close relationship between Linum bienne and Linum usitatissinum, and sustained the hypothesis that fibre flax has evolved from linseed.