Genetic diversity and association analysis using SSR markers in Brassica napus L. | 甘蓝型油菜SSR标记遗传多样性及其与农艺性状关联分析

Chinese. 研究甘蓝型油菜种质的遗传多样性，以提高甘蓝型油菜种质的利用效率。本研究从140对甘蓝型油菜SSR引物中，筛选出40对多态性好的SSR标记，并结合植株田间农艺性状特征鉴定，对63份来自四川的甘蓝型油菜种质资源进行遗传多样性、群体结构和性状关联分析。研究结果表明：40对多态性好的引物共检测到152个等位变异，引物平均多态性位点3.8，平均多态信息量（PIC）0.8497；在带型分析基础上，根据相似系数将参试材料聚为5大类群，多数参试材料属于第2、3大类群；在SSR多态信息基础上，对参试材料进行群体结构分析，将参试材料分为4个群体，86％的参试材料Q值大于0.70。对40个SSR位点与8个主要农艺性状用TASSEL软件的GLM（general linear model）模型进行关联分析，共检测到15个位点与农艺性状显著相关，其中6个位点极显著相关。这6个SSR位点分别为：yw222和ywy05标记与全株角果数极显著相关，yw140和yw134标记与主序角果数极显著相关，ywy19和yw138标记与一次分支数极显著相关；其中ywy19同时与每角粒数、主序角果数、主序有效长显著相关。研究结果表明，本研究参试材料具有较好的代表性，遗传多样性较丰富；研究分析所得与农艺性状极显著关联的SSR标记位点在提高甘蓝型油菜种质的利用效率方面具有重要的实践意义。

English. In order to improve the efficiency of using Brassica napus germplasm ano genetic disversity or B. napus germplasm by using SSR markers. A total of 40 polymorphic SSR markers which were selected from 140 B. napus SSR primers were employed for polymorphism and genetic diversity analysis of 63 B. napus germplasm. Furthermore, population structure was analyzed through the markers, and then association analysis between 40 SSR markers and 8 agronomic traits was performed using TASSEL GLM (General Linear Model) procedure. In this research, a total of 399 alleles were detected from 63 materials. Primers average alleles was 4.784 and the average PIC (polymorphism information content) values was 0.849 7; according to the similarity coefficient, the tested materials was composed of 5 groups, the majority of them were classified to group 2 and 3; according to structural analysis, the tested materials were divided into four groups on the basis of the SSR polymorphism information. The Q value of 86% tested materials was greater than 0.70. A total of 15 SSR markers were significantly associated with agronomic traits, among which 6 SSR markers had highly significant correlation under GLM procedure. Among which yw222 and ywy05, were highly significantly associated with the number of effective silique per plant, ywl40 and yw134 with No. of pods of main inflorescence, ywy19 and yw138 with No. of the first branches; ywy19 was significantly associated with No. of seeds per silique, No. of pods of main inflorescence and length of mail inflorescence simultaneously. The results showed that the germplasm in this study has good representation and rich genetic diversity; The SSR loci which were highly significantly associated with agronomic traits in this study may have an important practical significance in the utilization of B. napus germplasm.