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由Ralstonia solanacearum E.F.Smith引起的青枯病是若干亚洲和非洲国家花生生产的重要限制因子,利用抗病品种是防治这一病害最好的措施。虽然一大批抗青枯病花生种质资源材料已被鉴定出来,但对其遗传多样性没有足够的研究,限制了在育种中的有效利用。本研究以31份对青枯病具有不同抗性的栽培种花生种质为材料,通过简单序列重复(SSR)和扩增片段长度多态性(AFLP)技术分析了它们的遗传多样性。通过78对SSR引物和126对AFLP引物的鉴定,筛选出能显示抗青枯病种质多态性的SSR引物29对和AFLP引物32对。所选用的29对多态性SSR引物共扩增91条多态性带,平均每对引物扩增3.14条多态性带;32对多态性AFLP引物共扩增72条多态性带,平均扩增2.25条多态性带。在所筛选引物中,4对SSR引物(14H06,7G02,3A8,16C6)和1对AFLP引物(P1M62)检测花生多态性的效果优于其他引物。SSR分析获得的31个花生种质的遗传距离为0.12-0.94,平均为0.53,而AFLP分析获得的遗传距离为0.06～0.57,平均为0.25,基于SSR分析的遗传距离大于基于AFLP分析的遗传距离,疏枝亚种组的遗传分化相对大于密枝亚种组。基于两种分析方法所获得的聚类结果基本一致,但SSR数据聚类结果与栽培种花生的形态分类系统更为吻合。根据分析结果,对构建青枯病抗性遗传图谱群体的核心亲本和抗性育种策略提出了建议。
Bacterial wilt caused by Ralstonia solanacearum E.F. Smith is an important limiting factor for peanut production in several Asian and African countries. The use of resistant varieties is the best measure to control this disease. Although a large number of perennial germplasm resources for resistance to bacterial wilt have been identified, insufficient research on their genetic diversity has limited their effective use in breeding. In this study, 31 cultivars of peanut germplasm with different resistance to bacterial wilt were used as materials. Their genetic diversity was analyzed by simple sequence repeat (SSR) and amplified fragment length polymorphism (AFLP). By screening 78 pairs of SSR primers and 126 pairs of AFLP primers, 29 pairs of SSR primers and 32 pairs of AFLP primers were screened for their resistance to bacterial wilt. A total of 91 polymorphic bands were amplified with 29 polymorphic SSR primers and 3.14 polymorphic bands were amplified with each pair of primers. Thirty-two AFLP primers amplified 72 polymorphic bands, An average of 2.25 polymorphic bands were amplified. Among the selected primers, 4 SSR primers (14H06, 7G02, 3A8 and 16C6) and 1 pair of AFLP primers (P1M62) were more effective than other primers in detecting peanut polymorphism. SSR analysis showed that the genetic distance of 31 peanut germplasms was 0.12-0.94 with an average of 0.53 while that of AFLP analysis was 0.06-0.57 with an average of 0.25. The genetic distance based on SSR analysis was greater than the genetic distance based on AFLP analysis , The genetic differentiation of sparse branch subspecies group is relatively larger than that of the small branch seed subgroup. The results of clustering based on the two methods are basically the same, but the result of SSR data clustering is more consistent with the morphological classification system of cultivated peanut. Based on the results of the analysis, suggestions were made to construct the core parents and resistance breeding strategy of the bacterial wilt resistance genetic map.