【作者】 陈华；

【导师】 姚源松； 张世煌；

【作者基本信息】 新疆农业大学 ， 作物遗传育种， 2004， 硕士

【摘要】 划分玉米杂种优势群是研究和利用杂种优势的重要内容，是提高育种效率，建立高产杂种优势模式的重要依据。本研究利用SSR分子标记技术，分析我国北方玉米育种广泛使用的自交系之间的遗传关系，并结合育种实践划分杂种优势群。主要结果如下：（1） 从CIMMYT-AMBIONET Service实验室提供的79对SSR核心引物目录中，选出71对引物对99份玉米自交系进行遗传多样性研究，共检测到313个多态性条带，平均每个位点的等位基因变异数4.41个，变化范围2～9个，平均PIC值为0.61，变化范围0.224（nc133）～0.844（umc1196），所得数据与亚洲玉米生物技术协作网（AMBIONET）公布的数据略有差异。（2）利用分子标记所得的遗传距离，可将99份自交系划分为七个类群，即Lancaster群，BSSS群，旅大红骨和PA群，四平头群，PB群，热带种质群和国内地方种质群。聚类结果与已知系谱基本一致，划群后群间平均遗传相似系数都小于群内平均遗传相似系数，表明分类合理。同时，将一些地方种质和系谱不明的自交系划入到相应的杂种优势类群中。实验中加入6个国内的温带标准测验种和6个CIMMYT标准测验种，用来评价划群结果，并与其他实验室的资料相整合，扩大评价范围。（3）用同样的方法将供试自交系中的东北春玉米自交系划分为三大类群和五个亚群，即Lancaster亚群，BSSS，旅大红骨和PA亚群，PB亚群，四平头亚群和其它种质亚群。通过本研究对东北春玉米区的种质基础，及其与国内外种质的遗传关系，有了初步的认识。（4）通过比较，认为引物数和多态性位点数与划群结果有密切关系，划分杂种优势群的最小引物数和多态性位点数分别为50和220左右。更多还原

【Abstract】 Classifying inbred lines into heterotic groups is an important issue in hybrid maize (Zea mays L.) development. It is not only the basis for utilization of heterosis, but the foundation for establishing corresponding heterotic patterns to enhance the efficiency of hybrid maize breeding. In this research, simple sequence repeats (SSRs) were assigned to investigate the genetic diversity among 99 inbred lines, which were widely utilized in maize breeding program in north China. All these lines were divided into several heterotic groups. It would be helpful to enhance the efficiency of maize breeding in north China. The main results of the study were summarized as follows.(1) Seventy-one SSR primers selected from 79 SSR primers (based on CIMMYT-AMBIONET Service Lab) were used in the genetic diversity investigation of the 99 inbred lines in north China. In total, the seventy-one primers produced 313 polymorphic amplified fragments. The number of alleles per SSR locus averaged to 4.41 with the range from 2 to 9. The polymorphism information content (PIC) for all the SSR primers varied from 0.224 to 0.844 with an average of 0.61. (2) In order to assign the classification results to heterotic groups and combine all the relevant data with those from other labs, 6 domestic common testers and another 6 testers from CIMMYT were adopted in the experiment. The 99 inbred lines were classified into seven groups by UPGMA (unweightied pair group method agrithmetic average) based on GS (genetic similarity) from SSR fingerprinting data, i.e. Lancaster, Ried, Luda red cob and PA, Sipingtou, PB, and Tropical germplasm. The classification accorded with the heterrotic groups determined by the pedigree analysis. Consequently, SSR was proved to be a powerful tool in measuring genetic variation and assigning some pedigree-anonymous inbred lines into the current heterotic groups.(3) Seventy-eight inbred lines used in North-eastern China breeding program were classified into three groups and five sub-groups, Lancaster, Ried, Luda red cob and PA, Sipingtou, PB, and the others. Therefore, the genetic framework of maize breeding program in the North-eastern China and its relationship to the domestic and exotic germplasm were revealed.(4) Through the comparison of the grouping result based on different alleles, it was found that the number of polymorphic locus and the number of SSR primers in the genetic <WP=9>diversity analysis were the most critical factors to the classification. It was recommended as 220 and 50 respectively for the least number of polymorphyic loci and the number of SSR primers to classify heterotic groups.更多还原