花生栽野杂种特异新种质含油量相关标记位点的发掘

Peanut with squeezing oil purpose is the dominant direction of peanut industry and improving the oil content is an important goal of peanut breeding in China. But the lack of elite resources with high and stable oil content and the poor knowedge of the basic genetics for oil limit the progress of peanut breeding for high oil content. Previously research shows that the oil content of wild peanut is significantly higher than that of cultivated peanut. Using the different new genotypes derived from wide crosses between cultivated peanut and wild relatives with high oil content and breeding varieties as materials, the project will analyze the oil content difference of the new genotypes and breeding varieties through detecting the variation of oil content of these materials. Meanwhile the diversity of the materials will be detected by SSR markers. On the basis of kinship,population structure and linkage disequilibrium of the materials,we can find the marker loci related to oil content through the association analysis from SSR data and oil content. The effect of each locus on the oil content can be calculated.The differences of loci number and loci effect on oil content among the new genotypes derived from wide crosses between cultivated peanut and wild relatives with hihg oil content and breeding varieties can be analyzed. Using the markers related to oil content detect the various hybrid progeny with various oil content, we can obtain practical markers and elite genotypes with high oil content. The result from the project will provide materials and molecular assisted selection method for oil content in peanut breeding.

油用型花生是我国花生产业的主导方向，提高含油量是我国花生育种的重要目标。但是，优良高油资源缺乏和遗传基础研究薄弱限制了花生高油育种的进展。前期研究结果表明，野生花生的含油量显著高于栽培种花生。本项目拟以含有不同高油野生种亲缘的花生栽野杂种特异新种质和育成品种为材料，系统检测含油量的变异，分析栽野杂种特异新种质与育成品种含油量的差异。用SSR技术检测这些材料的多态性，在kinship、群体结构和连锁不平衡分析的基础上，通过关联分析获得含油量相关的标记位点，分析各位点对含油量的效应，比较不同的栽野杂种特异新种质之间以及特异新种质与育成品种之间标记位点的差异。用这些相关标记鉴定各种杂交后代，同时检测具有相关标记的后代材料的含油量，获得优良的种质材料和分子标记。本项目的开展将为深化花生高油育种提供理论依据、材料基础和选择方法。

本项目针对我国生产上应用的花生品种含油量偏低且不稳定、育种中优良高油资源相对缺乏、含油量遗传基础研究薄弱等问题，选取200份含有不同高油野生种亲缘的花生栽野杂种资源和200份含油量变异丰富的花生育成品种，连续3年4个环境点开展了含油量性状的测定及表型差异分析。研究发现栽野杂种含油量总体高于育成品种，并鉴定获得6份多环境含油量超过55%的稳定高油材料。利用毛细管电泳技术获得了584个具有多态性的SSR标记基因型数据，覆盖了全部20条染色体。分析基因型数据，发现整个资源群体的平均等位位点数目超过6个，遗传多样性指数为0.5，群体结构含三个亚群。通过比较栽野杂种与育成品种间标记位点差异，发现115个栽野杂种特异的等位位点。根据亲缘关系分析结果，选取遗传差异大的120份栽野杂种材料和174份育成品种材料进行关联分析。多环境下的关联分析一共获得了106个表型贡献率为3.28-12.26%的含油量关联标记，其中有49个关联标记在多个环境下被检测到。分析关联标记等位位点效应值，发现了4个栽野杂种特异的高油等位位点。另外利用两个重组自交系群体（中花10 × ICG12625和徐花 13 × 中花 6）共定位了13个含油量QTL，遗传解释率为5.39-26.39%。其中有两个主效的QTL（qoilA08和qoilB03.2）能够在多个环境下重复检测到。比较关联分析和连锁分析的结果，发现两个关联标记（AGGS1014_2和AHGS1727）与含油量QTL紧密连锁。多环境下分析标记等位位点效应，发现AGGS1014_2-215和AHGS1727-297为稳定有效的高油标记等位位点。用获得的高油标记分析已鉴定的稳定高油材料6份，发现这些材料具有的高油等位位点不尽相同，可通过杂交聚合不同的高油位点，进一步提高花生品种的含油量。