大豆3个核心亲本及其衍生品系基于PAV分子标记的亲缘关系研究

Genetic Relationship of Three Soybean Core Parents and Their Derived Breeding Lines Detected by Presence/Absence Variation Markers

基因组大片段序列存在/缺失变异(presence/absence variation,PAV)作为一种基于PCR技术、方便快捷的新标记受到人们的关注,但在大豆遗传育种工作中的应用较少。大豆育种计划中一般会有一批核心亲本,揭示其作用特点有助于亲本选配。应用PAV标记对国家大豆改良中心种质创新计划中3个核心亲本(南农86-4、南农88-48和诱处4号)与国内外材料杂交所获得34个组合衍生品系及亲本共154份材料所构建的样本进行核心亲本对其衍生品系遗传贡献分析。结果表明:221个PAV标记的平均等位变异数为2.1,多态性信息含量指数(PIC)平均为0.239,位于基因内和基因间标记的丰富度和PIC平均值相当。基于PAV标记信息可将34个供试组合聚为6类,其中3个大类可分别与3个核心亲本的组合相对应,核心亲本与其衍生品系的遗传距离最小。154份材料可聚为9类,来自同一核心亲本、同一组合的材料多聚在一起,但也存在交叉现象。对23个单交和6个三交组合的亲本遗传贡献率分析表明,共有22个组合(占75.90%)的核心亲本对衍生品系的平均贡献率高于基于系谱的理论值,其中来自本地区的南农86-4、南农88-48对衍生品系的平均遗传贡献值总体上高于其它杂交亲本,而异生态区的诱处4号的贡献率相对较低。PAV标记能在系谱信息基础上进一步反映大豆亲本及衍生品系的亲缘关系。

A new molecular marker system, presence/absence variation （PAV） of large fragment genomic sequences shows potential because of its convenient PCR-based technique and distinct band distribution on.However, its application in soybean breeding and genetic research remains to be carried. There are some core parents in soybean breeding program, which are the key to success in breeding, revealing their role is helpful for parent selection in hybrid breeding work. In this study, total 154 soybean materials including 28 parents and 126 breeding lines were used to reveal their genetic relationship.These lines were derived from the crosses between three core parents （Nannong 86.4, Nannong 88.48 and Youchu 4） and a set of domestic and exotic lines in a breeding program in National Center of Soybean Improvement. The average number of allele per PAV was 2.1.The average value of polymorphic information content （PIC） per PAV was 0.239. The average allele number of the gene-based and non-coding region PAV marker and the average values of polymorphic information content （PIC） of the two PAV types were almost the same. All 34 crosses were clustered into 6 groups based on PAV markers data, among them, three big groups correspond to the three core parents could be identified.All 154 materials were clustered into 9 groups. Most lines from the same core parent or same cross were classified as a group. According to the genetic contribution rate of PAV allele of the core parents, 22 crosses had higher average contribution rate than the expected ratio in the 29 crosses. The observed contribution values of core parent Nannong 86.4, Nannong 88.48 were higher than the expected values based on pedigree analysis, while Youchu 4 from other region had less contribution to the derived lines, indicating the rationalities of using local elite line as core parent in breeding program. In comparison with pedigree analysis, PAV marker can reveal detail genetic relationship among the parents and their derived lines.