花生侧枝角度性状的遗传分析和QTL定位

Peanut is an important oil crops, industrial crops and export crops in China. Lateral branch angle, as an important agronomy trait of plant type, directly affects the distance of fruit-needles to the earth, pods concentration degree, and also closely relates with the population yield and tillage management of peanut. Due to lack of quantitative and decomposition index of lateral branch angle, resulting in few genetic research on systematic evaluation and dissection of related traits, and restrictions on selection breeding of peanut varieties with suitable for mechanized and plant type of high yield. Aimed at this problem, in this project, segregation populations derived from two peanut cultivars with significantly different lateral branch angle will be used as materials to systematically measure the variation of lateral branch angle and study genetic characteristics of lateral branch angle in peanut. Based on BSA-Reseq and SSR analysis, a genetic map will be constructed and used to map QTLs controlling lateral branch angle in peanut. And QTLs consistency will be studied between lateral branch angle and others important traits by meta-analysis. This project will lay a theoretical foundation for molecular mechanism dissection of lateral branch angle and selection breeding of new peanut varieties with suitable for mechanized and plant type of high yield.

花生是我国重要的油料作物、经济作物和出口创汇作物。侧枝角度是决定株型的一个重要农艺性状，直接影响花生果针的入土距离和结果集中程度，亦与群体产量和耕作方式有着密切关系。由于缺乏侧枝角度的量化分解指标，导致系统评价和解析株型性状侧枝角度的遗传研究较少，限制了适宜机械化、高产株型花生品种的选育。本项目针对这个难题，拟以侧枝角度差异较大的花生品种杂交构建的分离群体为材料，系统地调查侧枝角度性状的变异，分析花生侧枝角度的遗传特性；通过BSA重测序和SSR分析，构建遗传连锁图谱，定位花生侧枝角度相关的QTLs；利用Meta分析研究侧枝角度与花生其它重要性状QTL之间的一致性。本项目的开展将为解析花生侧枝角度的分子机制和选育适宜机械化、高产株型的花生新品种奠定理论基础。

花生是我国重要的油料作物、经济作物和出口创汇作物。侧枝角度是决定株型的一个重要农艺性状，直接影响花生果针的入土距离和结果集中程度，亦与群体产量和耕作方式有着密切关系。由于缺乏侧枝角度的量化分解指标，导致系统评价和解析株型性状侧枝角度的遗传研究较少，限制了适宜机械化、高产株型花生品种的选育。本研究以直立型花生材料“冀花5”和匍匐型花生材料“M130”为亲本构建的F2群体为研究材料，采用BSA测序法获得与侧枝角度性状相关联的标记区间为B05染色体的142,610,834bp-146,688,220bp，而通过SSR等传统分子标记技术定位与侧枝角度相关性状的QTL位点，未在B05染色体上检测到相关QTL。进而我们采用特异性位点扩增片段测序技术（SLAF-seq）对经过连续自交获得的F8重组自交系群体进行测序，通过构建高密度遗传图谱结合7个环境的侧枝角度相关性状的表型数据，获得与性状相关的主效QTL位于B05的159,819,755bp-159,987,803bp。为了进一步证实B05上的主效QTL区域，本研究以120份美国花生微核心种质构成的自然群体为供试材料，采用48 K Affymetrix 2.0芯片筛选对群体进行连锁不平衡分析，并结合两个环境下的侧枝角度相关性状的表型数据进行GWAS分析，发现位于B05上的SNP（AX-147251085，144,353,467bp）与侧枝基角显著关联，该结果与BSA-seq吻合。最后，我们对B05的关联区域或主效QTL区域内的基因进行了注释分析，共发现102个与植物生长发育相关的基因。本研究结果将为解析花生侧枝角度的分子机制和选育适宜机械化、高产株型的花生新品种奠定理论基础。