National Centre for Evaluation of Agricultural Wild Plants (Rice), MOE Key Laboratory of Crop Heterosis and Utilization, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
Arizona Genomics Institute, School of Plant Sciences, University of Arizona, Tucson, Arizona 85721, USA.
Nat Plants. 2017 May 8;3:17064. doi: 10.1038/nplants.2017.64.
Grain size is one of the most important components of grain yield and selecting large seeds has been a main target during plant domestication. Surprisingly, the grain of African cultivated rice (Oryza glaberrima Steud.) typically is smaller than that of its progenitor, Oryza barthii. Here we report the cloning and characterization of a quantitative trait locus, GL4, controlling the grain length on chromosome 4 in African rice, which regulates longitudinal cell elongation of the outer and inner glumes. Interestingly, GL4 also controls the seed shattering phenotype like its orthologue SH4 gene in Asian rice. Our data show that a single-nucleotide polymorphism (SNP) mutation in the GL4 gene resulted in a premature stop codon and led to small seeds and loss of seed shattering during African rice domestication. These results provide new insights into diverse domestication practices in African rice, and also pave the way for enhancing crop yield to meeting the challenge of cereal demand in West Africa.
粒型是决定谷物产量的最重要因素之一，在植物驯化过程中，选择大粒种子一直是主要目标。令人惊讶的是，非洲栽培稻（Oryza glaberrima Steud.）的谷粒通常比其祖先是 Oryza barthii 的谷粒要小。在这里，我们报道了一个控制非洲稻 4 号染色体上粒长的数量性状基因座 GL4 的克隆和特性，该基因座调节外稃和内稃的纵向细胞伸长。有趣的是，GL4 还像亚洲稻中的同源基因 SH4 一样控制着种子散落表型。我们的数据表明，GL4 基因中的单个核苷酸多态性（SNP）突变导致提前出现终止密码子，导致非洲稻驯化过程中种子变小和种子散落丧失。这些结果为非洲稻的多样化驯化实践提供了新的见解，也为提高作物产量以满足西非对谷物需求的挑战铺平了道路。
