莲子产量相关性状的QTL定位

以中国长江流域圆柱形莲子资源‘中间湖野莲’为母本，泰国圆球形莲子资源‘清迈野莲’为父本，构建了含86个单株的F2遗传群体。2017和2018年对亲本及群体黑子期莲子长、莲子宽、单粒质量、开花数、心皮数、饱粒数等6个莲子产量相关性状进行了表型鉴定，利用197个SSR标记对亲本及F2单株进行基因分型，结合表型和基因型数据对相关性状进行了QTL定位和分析。结果表明：莲子产量相关性状在F2群体中均呈近正态连续分布，表明均为多基因控制的数量性状。6个莲子产量相关性状共检测到28个QTL位点，分布在7条连锁群上，LOD值变幅为2.55 ~ 12.34，可解释5.5% ~ 27.4%表型变异率。贡献率 ≥ 10的QTL位点有25个，占QTL总数的89.29%。黑子期莲子长（bsl1），莲子宽（bsw6）、开花数（fn4.1，fn5）可在两年被稳定检测到，贡献率变幅为7.33% ~ 17.6%。

QTL Mapping of Six Seed Yield Related Traits in Lotus

In this study，a F2 population of lotus including 86 individuals was constructed with the cylindrical type accession‘Middle Lake Wild Lotus’and spherical type‘Chiang Mai Wild Lotus’as female and male parents，respectively. By combining the phenotypic identification of the F2 individuals and the parents in 2017 and 2018 with the genotyping by 197 SSR markers，QTL mapping of six yield-related traits（i.e.，black seed length，black seed width，single seed weight，flower number，carpel number and seed number per seedpod）was carried out. The results showed that all the six yield-related traits were close to continuous normal distribution in the F2 population，which indicated that these traits are quantitative traits controlled by multi genes. In total，twenty-eight QTLs that distributed on seven linkage groups were identified in the two years’ experiments，which explained 5.5%–27.4% of the phenotypic variation with LOD values between 2.55 and 12.34. Twenty-five QTLs（accounting for 89.29% of total QTLs）explained more than 10% phenotypic variation. Four of the twenty-five QTLs i.e.，black seed length（bsl1），black seed width（bsw6）and flower number fn4.1，fn5）] were repeatedly identified over the two years，explaining 7.33% to 17.6% phenotypic variantion.