玉米穗行数主效QTL qkrn8 的精细定位与候选基因分析

Maize kernel row number (KRN) is one of the important traits associated with ear development and grain yield. KRN is stable across environments, and its broad-sense heritability is very high. Therefore, it is feasible to isolate genes underlying KRN through map-based cloning. In our previous studies, a major QTL for KRN, qkrn8, was identified using SLAF-seq-based high-density linkage map based on a F2 population. And qkrn8 was also detected by using BSR-seq based on plants with extreme KRN phenotype in the F2 population. Based on the constructed advanced segregating population, we plan to fine map qkrn8. Combining RNAseq between near isogenic lines, candidate gene association mapping, and CRISPR-Cas9-based gene knock-out, the candidate gene for qkrn8 will be identified. The results would found the basis for gene function charactorization and molecular mechanism of qkrn8. Besides, the molecular breeding tools for KRN traits based on qkrn8 would be developed.

玉米穗行数是与雌花发育和产量均紧密相关的重要性状，遗传力高，受环境因素影响小，也是单株产量构成因子中最有可能通过图位克隆策略开展基因分离与功能鉴定的性状，具有重要的研究价值与前景。本申请将在前期基于F2群体SLAF-seq和BSR-seq初级定位与交互验证发现的一个重要主效QTL (qkrn8)的基础上，利用已构建的BC3F1次级分离群体，进一步精细定位qkrn8，并通过突变体与近等基因系转录组测序分析、候选基因关联分析、CRISPR-Cas9基因定点敲除等手段确定候选基因，为基因功能鉴定奠定重要的材料与分析基础，同时也针对该QTL的遗传育种开发分子育种工具。

玉米穗行数是与雌花发育和产量均紧密相关的重要性状，遗传力高，受环境因素影响小，也是单株产量构成因子中最有可能通过图位克隆策略开展基因分离与功能鉴定的性状，具有重要的研究价值与前景。在本项目的资助下，我们利用基于F2群体的高密度连锁图谱，结合F2单株的穗行数表型，在第8染色体发现了控制穗行数的QTL qkrn8-1，并用RNAseq等方法进行了验证，后期结合重组单株自交后代的表型与基因型开展精细定位，并对候选基因进行了分析，为基因功能鉴定奠定了重要的材料基础，同时也针对该QTL的遗传育种开发分子育种工具。以本项目为第一标注发表SCI论文1篇，培养学生1名。