Yu Lin;Xiaojun Jiang;Haiyan Hu;Kunyu Zhou;Qing Wang;Shifan Yu;Xilan Yang;Zhiqiang Wang;Fangkun Wu;Shihang Liu;Caixia Li;Mei Deng;Jian Ma;Guangdeng Chen;Yuming Wei;Youliang Zheng;Yaxi Li

Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu 611130, Sichuan, China;Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu 611130, Sichuan, China;School of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, Henan, China;State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Wenjiang, Chengdu 611130, Sichuan, China;College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu 611130, Sichuan, China; Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu 611130, Sichuan, Chin

Chinese Spring;Grain number per spikelet;High-density map;KASP;Quantitative trait locus;GENOME-WIDE ASSOCIATION;HEXAPLOID WHEAT;LINKAGE;TRAITS;SELECTION;LOC

Grain number per spikelet (GNS) is a key determinant of grain yield in wheat. A recombinant inbred line population comprising 300 lines was developed from a cross between a high GNS variety H461 and Chinese Spring from which the reference genome assembly of bread wheat was obtained. Both parents and the recombinant inbred lines were genotyped using the wheat 55K single nucleotide polymorphism (SNP) array. A high-density genetic map containing 21,197 SNPs was obtained. These markers covered each of the 21 chromosomes with a total linkage distance of 3792.71 cM. Locations of these markers in this linkage map were highly consistent with their physical locations in the genome assembly of Chinese Spring. The two parents and the whole RIL population were assessed for GNS in two consecutive years at two different locations. Based on multi-environment phenotype data and best liner unbiased prediction values, three quantitative trait loci (QTL) for GNS were identified. One of them located on chromosomes 2B and the other two on 2D. Phenotypic variation explained by these loci varied from 3.07% to 26.57%. One of these QTL, QGns.sicau-2D-2, was identified in each of all trials conducted. Based on the best linear unbiased prediction values, this locus explained 19.59%-26.57% of phenotypic variation. A KASP (Kompetitive Allele-Specific PCR) marker closely linked with this locus was generated and used to validate the effects of this locus in three different genetic backgrounds. The identified QTL and the KASP marker developed for it will be highly valuable in fine-mapping the locus and in exploiting it for markerassisted selection in wheat breeding programs. (C) 2021 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.