中国农业科学 ›› 2016, Vol. 49 ›› Issue (3): 593-608.doi: 10.3864/j.issn.0578-1752.2016.03.017

• 研究简报 • 上一篇    

中国西南地区甘薯主要育种亲本的遗传多样性及群体结构分析

罗凯1,卢会翔1,吴正丹1,吴雪莉1,尹旺1,唐道彬1,2,王季春1,2,张凯1,2   

  1. 1西南大学农学与生物科技学院,重庆400716
    2重庆市甘薯工程技术研究中心,重庆400716
  • 收稿日期:2015-08-13 出版日期:2016-02-01 发布日期:2016-02-01
  • 通讯作者: 王季春,E-mail:wjchun@swu.edu.cn;张凯,E-mail:zhangkai2010s@163.com
  • 作者简介:罗凯,E-mail:luokai1112@126.com。卢会翔,E-mail:luhuixiangswu@163.com。罗凯和卢会翔为同等贡献作者。
  • 基金资助:
    国家自然科学基金(31101192)、重庆市应用开发计划项目重点项目(cstc2013yykfB80010)、中央高校基本科研业务费专项资金项目(XDJK2014B038,XDJK2012C102,2362015xk05)、重庆市社会事业与民生保障科技创新专项(cstc2015shms-ztzx0121,cstc2015shms- ztzx0128)、重庆市自然科学基金重点项目(cstc2012jjB80009,cstc2013jjB80006)

Genetic Diversity and Population Structure Analysis of Main Sweet Potato Breeding Parents in Southwest China

LUO Kai1, LU Hui-xiang1, WU Zheng-dan1, WU Xue-li1, YIN Wang1, TANG Dao-bin1,2WANG Ji-chun1,2, ZHANG Kai1,2   

  1. 1College of Agronomy and Biotechnology, Southwest University, Chongqing 400716
    2Chongqing Sweet Potato Engineering Technological Research Center, Chongqing 400716
  • Received:2015-08-13 Online:2016-02-01 Published:2016-02-01

摘要: 【目的】探究中国西南地区主要甘薯育种亲本材料的遗传多样性和群体结构,为甘薯亲本材料的保存和利用、甘薯分子标记辅助选择提供参考依据。【方法】利用61个SSR分子标记、13个农艺性状和6个品质性状,对82份中国西南地区主要甘薯育种亲本材料进行遗传多样性分析。利用NTSYS-pc 2.10数据处理软件,分别根据SSR分子标记数据、品质性状、农艺性状计算82份亲本材料的Nei72遗传距离矩阵。利用Mega 6.06数据处理软件,计算82份材料基于SSR分子标记、品质性状、农艺性状的平均遗传距离。利用NTSYS-pc 2.10软件,对供试材料基于SSR标记、品质性状和农艺性状的遗传距离矩阵进行相关性分析。根据遗传距离矩阵,利用Mega6.06软件分别,对82份亲本材料进行基于品质性状的类平均法(unweighted pair group method with arithmetic mean,UPGMA)聚类分析、基于SSR分子标记的邻接法(Neighbor-Joining,NJ)聚类分析和基于农艺性状的类平均法(UPGMA)聚类分析。根据SSR分子标记数据,利用STRUCTURE 2.4对82份供试材料进行群体结构分析。【结果】61对SSR引物共检测出405条多态性谱带,其中,每对引物获得1—17条多态性谱带,平均每对引物检测出6.64条多态性谱带。82份亲本材料基于SSR分子标记、品质性状、农艺性状的Nei平均遗传距离分别为0.3499、0.2210和0.0270。基于SSR分子标记的邻接法(NJ)聚类分析将82份材料聚为7个类群。基于农艺性状、品质性状的类平均法(UPGMA)聚类分析均可将82份材料划分为一个较大的类群和三个较小的类群,但基于农艺性状和品质性状的聚类分析结果差异较大。基于SSR分子标记、品质性状和农艺性状的聚类分析均能将供试材料中来自不同地区的材料聚为同一类群,表明不同地理来源的供试材料间没有明显的遗传差异。遗传距离矩阵之间的相关性分析表明,基于SSR标记、品质和农艺性状的遗传距离矩阵间的相关性很小(r=0.0158),品质性状与农艺性状间呈负相关(r=-0.0411)。群体结构分析表明,当K等于3时,ΔK说明82份材料可以划分为3个亚群。取得最大值,其中53份(64.63%)供试材料的Q值大于或等于0.6,分属于3个亚群。29份材料(35.37%)划分为混合亚群。群体结构分析的亚群划分结果与SSR聚类分析结果有一定相似性。【结论】供试亲本材料基因组水平的遗传多样性较为丰富,品质性状有一定差异,农艺性状差异较小。单独利用某一种标记或性状对亲本材料进行衡量都不全面,建议结合分子标记和多种表型性状,进行深入的遗传多样性和群体结构分析

关键词: 甘薯, 遗传多样性, 群体结构, 农艺性状, SSR, 品质性状

Abstract: 【Objective】 To provide a reference for the conservation and application of breeding parentallines resource, as well as molecular assistant selection (MAS) in sweet potato (Ipomoea batatas), a comprehensive analysis of genetic diversity and population structure analysis of the main sweetpotato breeding parentallines in southwest China was performed. 【Method】 Genetic diversity of 82 main sweet potato breeding parents in southwest China was evaluated by using 61 sample sequence repeats (SSR) markers, 13 agronomic traits and 6 quality traits. The Nei72 genetic distance matrices of 82 tested sweet potato breeding parents were generated based on SSR markers while quality trait and agronomy trait were assessed using NTSYS-pc version 2.10. The mean genetic distance of the tested sweet potato breeding parents based on SSR marker, quality trait and agronomy trait were generated by using Mega version 6.06. Mantel test among genetic distance matrices generated based on SSR marker, quality trait and agronomic trait were conducted by using NTSYS-pc version 2.10. The unweighted pair group method with arithmetic mean (UPGMA) cluster analysis of 82 sweetpotato breeding parents based on quality trait, Neighbor-Joining (NJ) cluster analysis based on SSR marker and UPGMA cluster analysis based on agronomy trait were performed by using Mega version 6.06. Meanwhile, the population structure of 82 sweet potato genotypes was determined based on polymeric data generated by SSR markers using STRUCTURE version 2.4.【Result】 405 polymorphic loci were detected using 61 SSR markers with a mean of 6.64 alleles per primer pair. The number of polymorphic loci obtained from each primer pair ranged from 1 to 17. The SSR marker, quality trait and agronomic trait-based mean Nei’s genetic diversity of tested sweet potato breeding parents was 0.35, 0.22 and 0.03, respectively The tested 82 sweet potato genotypes could be divided into 7 subgroups based on NJ clustering using SSR markers. This same sweet potato collection could be divided into 1 major subgroup and 3 minor subgroups based on UPGMA method using either agronomic or quality traits, but the results showed differentiation. Among the tested sweet potato breeding parents, the genotypes with different original resources could be clustered into the same subgroups in the cluster analysis based on SSR marker, quality trait and agronomic trait, indicating there was no significant genetic differentiation among the tested sweet potato genotypes from different original resources. Mantel test detected little correlation among genetic distance matrices generated by using SSR marker, quality trait and agronomic trait (r=0.016), and a negative correlation (r=-0.041) was detected between genetic distance matrices generated by using quality and agronomic trait. The maximum ad hoc quantity ΔK was observed for K=3 in population structure analysis, indicating that the entire collection could be divided into three subpopulations. Using a membership probability threshold of ≥0.60, 53 genotypes (accounting for 64.6% of the tested genotypes) were assigned to the three subpopulations, and 29 (account for 35.4% of tested breeding parents) were retained in the admixed group (AD). The assignment of 82 sweetpotato genotypes determined by structure analysis was similar but not fully consistent with the assignment pattern of NJ clustering based on SSR marker. 【Conclusion】 Our results demonstrated that a wide genetic diversity at the genomic level was found among the tested main sweet potato breeding parental lines in southwest China. Genetic differentiation could be found in their quality traits, but little differentiation could be found in their agronomic traits. Furthermore, there exists a strong limitation in studying genetic diversity by using a single marker system or trait, and comprehensive analysis systems, combining molecular markers and various phenotypic traits should be given priority in further studies of genetic relationships and population structure of sweet potato breeding parental lines.

Key words: sweetpotato, genetic diversity, population structure, agronomic trait, SSR, quality trait