Teramoto Shota, Yamasaki Masanori, Uga Yusaku
Institute of Crop Science, National Agriculture and Food Research Organization, Tsukuba, Ibaraki 305-8518, Japan.
Food Resources Education and Research Center, Graduate School of Agricultural Science, Kobe University, Kasai, Hyogo 675-2103, Japan.
Breed Sci. 2022 Jun;72(3):222-231. doi: 10.1270/jsbbs.22010. Epub 2022 Jul 1.
To explore the genetic resources that could be utilized to help improve root system architecture phenotypes in rice (), we have conducted genome-wide association studies to investigate maximum root length and crown root number in 135 10-day-old Japanese rice accessions grown hydroponically. We identified a quantitative trait locus for crown root number at approximately 32.7 Mbp on chromosome 4 and designated it (). A linkage disequilibrium map around suggested that three candidate genes are involved in crown root number: a cullin (), a gibberellin 20 oxidase 8 (), and a cyclic nucleotide-gated ion channel (). The combination of haplotypes for each gene was designated as a haploblock, and haploblocks 1, 2, and 3 were defined. Compared to haploblock 1, the accessions with haploblocks 2 and 3 had fewer crown roots; approximately 5% and 10% reductions in 10-day-old plants and 15% and 25% reductions in 42-day-old plants, respectively. A Japanese leading variety Koshihikari and its progenies harbored haploblock 3. Their crown root number could potentially be improved using haploblocks 1 and 2.
为了探索可用于帮助改善水稻根系结构表型的遗传资源，我们开展了全基因组关联研究，以调查135份水培生长10天的日本水稻品种的最大根长和冠根数。我们在第4号染色体上约32.7兆碱基处鉴定出一个控制冠根数的数量性状位点，并将其命名为（）。围绕该位点的连锁不平衡图谱表明，有三个候选基因与冠根数有关：一个泛素连接酶（）、一个赤霉素20氧化酶8（）和一个环核苷酸门控离子通道（）。每个基因的单倍型组合被指定为一个单倍型块，并定义了单倍型块1、2和3。与单倍型块1相比，具有单倍型块2和3的品种冠根较少；在10日龄植株中分别减少约5%和10%，在42日龄植株中分别减少15%和25%。日本主栽品种越光及其后代具有单倍型块3。利用单倍型块1和2有可能改善它们的冠根数。
