Fine mapping of qKRN8, a QTL for maize kernel row number, and prediction of the candidate gene
Fine mapping of qKRN8, a QTL for maize kernel row number, and prediction of the candidate gene
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玉米粒行数QTL qKRN8精细定位及候选基因预测
DOI：
10.1007/s00122-020-03660-7
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发表时间：
2020-08-28
影响因子：
5.4
通讯作者：
Qiu, Fazhan
中科院分区：
文献类型：
--
作者：
Han, Xuesong;Qin, Yao;Qiu, Fazhan
qKRN8是玉米籽粒行数的主要QTL，在8号染色体上定位到520 kb左右的区间，并通过表达分析鉴定出关键候选基因。籽粒行数是影响玉米产量的重要性状之一，与玉米雌蕊花序发育密切相关。本研究利用低KRN系V54与高KRN系Lian87杂交的F-2:3群体，定位了玉米KRN数量性状位点（qtl）。我们在四种环境中鉴定了12个KRN qtl，每个qtl解释了1.40-14.95%的表型方差。其中，一个新的主要QTL（命名为qKRN8）在所有四种环境中被定位到bin 8.03，解释了8.79-14.95%的表型变异。通过结合基于图谱的克隆和重组体的后代测试，我们最终将qKRN8定位到一个类似于520 kb的基因组区间，包含6个假定的候选基因。其中1个候选基因在近等基因系qKRN8（Lian87）和qKRN8（V54）的未成熟穗中表达水平形成对比。这些发现将有助于KRN的分子育种和进一步鉴定该QTL的多态性。
Key message qKRN8, a major QTL for kernel row number in maize, was fine mapped to an interval of similar to 520 kb on chromosome 8 and the key candidate gene was identified via expression analysis. Kernel row number (KRN) is one of the most important yield-influencing traits and is closely associated with female inflorescence development in maize (Zea mays L.). In this study, an F-2:3 population derived from a cross between V54 (low KRN line) and Lian87 (high KRN line) was used to map quantitative trait loci (QTLs) conferring KRN in maize. We identified 12 QTLs for KRN in four environments, each explaining 1.40-14.95% of phenotypic variance. Among these, one novel major QTL (named qKRN8) was mapped to bin 8.03 in all four environments, explaining 8.79-14.95% of phenotypic variation. By combining map-based cloning with progeny testing of recombinants, we ultimately mapped qKRN8 to an similar to 520 kb genomic interval, harboring six putative candidate genes. Among them, one candidate gene showed contrasted expression level in immature ears of the near-isogenic lines qKRN8(Lian87) and qKRN8(V54). These findings should facilitate molecular breeding for KRN and the further identification of the polymorphism underlying this QTL.