Abstract:

Genetic similarities of 13 inbred lines of maize (Zea mays L.) were analyzed by restriction fragment length polymorphisms (RFLPs). The objectives of the study were to detect genetic similarities among 13 inbreds and to assign them to heterotic groups. By means of 24 probe-enzyme combinations (PECs) selected for locus specificity, clear patterns and reproducibility, 85 alleles were found with an average of 3.3 alleles per locus. The allelic frequency data were used to estimate genetic similarities among lines, and as a result the diversity index of 0.499 was obtained. Genetic similarities between the pairs of 13 lines ranged from 0.523 up to 0.802 with an average of 0.649. The UPGMA clustering algorithm analysis classified the 13 lines into five groups, which generally corresponded to known maize heterotic groups based on pedigree information. The authors concluded that RFLP-based markers could be used for investigating genetic relationships between maize inbred lines and assigning them to heterotic groups, but it seemed that a large number of PECs were needed to obtain reliable estimates of genetic similarity.

玉米自交系遗传变异的RFLP分析
李新海 傅骏骅 张世煌 袁力行 李明顺
（中国农业科学院作物育种栽培研究所，农业部作物遗传育种重点开放实验室，北京100081）

摘要：利用RFLP标记研究了 13个玉米 (Zeamays L .)自交系的遗传变异。从 30对探针 /酶组合中筛选出杂交带型清晰、稳定、重复性好的 2 4对组合 ,在 13个自交系中获得 85个等位基因杂交片段 ,平均每个位点为 3.3条 ,平均多态性指数为 0 .499。 13个自交系之间的遗传相似系数为 0 .5 2 3～ 0 .80 2 ,平均为 0 .6 49。UPGMA聚类分析表明 ,供试自交系共分为 5个类群 ,分群结果与其系谱关系基本吻合 ;表明利用RFLP标记可以研究玉米自交系之间的遗传关系 ,并将无系谱记载的自交系划分到相应类群中。

关键词： 玉米；RFLP 标记；遗传相似系数；杂种优势群

Key words: Zea mays, restriction fragment length polymorphisms (RFLPs), genetic similarity (GS), heterotic group