82份玉米自交系遗传多样性分析

Analysis of Genetic Diversity of 82 Maize Inbred Lines

对种质资源进行遗传关系的研究和遗传多样性评价是玉米育种研究的重要内容,采用形态标记和SSR分子标记2种方法对82份玉米自交系进行了遗传多样性分析。结果表明：用15个表型性状计算它们的欧式遗传距离,其平均遗传距离为50.57,变异范围为9.05-146.23,说明供试自交系遗传多样性丰富,以遗传距离38.06为界,将供试自交系分为6类,其聚类结果与其系谱来源的吻合程度较差;利用筛选出来的63对扩增条带清晰、多态性明显的SSR引物,在供试自交系中共检测出等位基因变异601个,每对引物检测到4-24个等位基因,平均为9.5个,每个位点多态性信息量（PIC值）变幅为0.454 6-0.916 9,平均为0.752 9,遗传相似系数为0.544 1-0.933 4,平均为0.667 3,以遗传相似系数0.673 5为界,将82份自交系分为七大类,属于五大常见类群的自交系占84.1%,其中Reid群占32.9%,PB群占23.2%,Lancaster群占13.4%,塘四平头群占7.3%,旅大红骨群占7.3%,其他2个类群分别占11.0%和4.9%,其聚类结果与其系谱来源的吻合程度较高。

The evaluation of germplasm resources diversities and the genetic relationships among germplasm have been an important part of maize breeding research. In this study,genetic diversities of 82 inbred lines were analyzed by morphological and SSR markers. The results showed that the average Euclidean distance calculated with15 phenotypic characters was 50. 57; the variation in the range was 9. 05- 146. 23,indicating that the genetic diversity of these inbred lines was rich. All the inbred lines could be divided into six groups with the genetic distance of38. 06 as an indicator. The clustering was not highly consistent with the pedigrees. Based on stable amplification profiles obtained and significant polymorphic,63 pairs of SSR primers were selected to detect 601 alleles,and the average number of alleles per locus was 9. 5 with a range from 4 to 24,and the values of polymorphism information content（ PIC） for each SSR locus varied from 0. 454 6 to 0. 916 9 with an average of 0. 752 9. The genetic similarities of SSR marker pattern ranged from 0. 544 1 to 0. 933 4 with an average of 0. 667 3. The 82 inbred lines were divided into seven groups according to their genetic similarity by bounded coefficient of 0. 673 5,among which inbred lines belonged to five family groups occupying 84. 1%. Among these inbred lines,32. 9% were Reid group,23. 2%PB,13. 4% Lancaster,7. 3% Tangsipingtou,and 7. 3% Lüdahonggu group,with the other inbred lines divided into two groups occupying 11. 0% and 4. 9%,respectively. The clustering was consistent with its genealogical sources.