Increased pericarp cell length underlies a major QTL for grain weight in hexaploid wheat
Increased pericarp cell length underlies a major QTL for grain weight in hexaploid wheat
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DOI：
10.1101/117937
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发表时间：
2017-03
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通讯作者：
J. Brinton;J. Simmonds;Francesca Minter;M. Leverington-Waite;J. Snape;C. Uauy
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文献类型：
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作者：
J. Brinton;J. Simmonds;Francesca Minter;M. Leverington-Waite;J. Snape;C. Uauy
必须提高作物产量，以解决粮食不安全问题。粒重由粒长和粒宽决定，是一个重要的产量构成因素，但我们对潜在的基因和机制的了解有限。利用遗传作图和近等基因系(NILs)对小麦5A染色体上一个与粒重相关的主效数量性状基因座(QTL)进行了定位、验证和精细定位。对来自近等基因系的发育和成熟籽粒进行了详细的表型特征分析。我们发现了一个与粒重增加6.9%相关的稳定而稳健的QTL。正间隔导致籽粒长4.0%，差异在受精后12天第一次可见。这种粒长效应被精确地绘制成4.3厘米的间隔。在籽粒发育后期，该基因对粒宽(1.5%)也有多效性效应，这决定了粒重增加的相对幅度。近等基因系正值增加了母体果皮细胞长度，这种效应与绝对粒长无关。这些结果为多倍体小麦果皮细胞长度影响最终籽粒大小和重量提供了直接的遗传证据。我们认为，结合控制不同生物机制的基因，如细胞扩张和增殖，将提高作物产量。
Crop yields must increase to address food insecurity. Grain weight, determined by grain length and width, is an important yield component, but our understanding of the underlying genes and mechanisms is limited. We used genetic mapping and near isogenic lines (NILs) to identify, validate and fine map a major quantitative trait loci (QTL) on wheat chromosome 5A associated with grain weight. Detailed phenotypic characterisation of developing and mature grains from the NILs was performed. We identified a stable and robust QTL associated with a 6.9 % increase in grain weight. The positive interval leads to 4.0 % longer grains, with differences first visible twelve days post fertilization. This grain length effect was fine-mapped to a 4.3 cM interval. The locus also has a pleiotropic effect on grain width (1.5 %) during late grain development that determines the relative magnitude of the grain weight increase. Positive NILs have increased maternal pericarp cell length, an effect which is independent of absolute grain length. These results provide direct genetic evidence that pericarp cell length affects final grain size and weight in polyploid wheat. We propose that combining genes which control distinct biological mechanisms, such as cell expansion and proliferation, will enhance crop yields.