Yi Xiaoyu, Ye Yingtong, Wang Jinhui, Li Zhen, Li Jiamin, Chen Yuqi, Chen Guoyue, Ma Jian, Pu Zhien, Peng Yuanying, Qi Pengfei, Liu Yaxi, Jiang Qiantao, Wang Jirui, Wei Yuming, Zheng Youliang, Li Wei
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, China.
College of Agronomy, Sichuan Agricultural University, Chengdu, China.
Front Plant Sci. 2023 May 10;14:1144486. doi: 10.3389/fpls.2023.1144486. eCollection 2023.
The total number of spikelets (TSPN) and the number of fertile spikelets (FSPN) affect the final number of grains per spikelet in wheat. This study constructed a high-density genetic map using 55K single nucleotide polymorphism (SNP) arrays from a population of 152 recombinant inbred lines (RIL) from crossing the wheat accessions 10-A and B39. Twenty-four quantitative trait loci (QTLs) for TSPN and 18 QTLs for FSPN were localized based on the phenotype in 10 environments in 2019-2021. Two major QTLs, (34.43-47.43 Mb) and (32.97-34.43 Mb), explained 13.97%-45.90% of phenotypic variation. Linked kompetitive allele-specific PCR (KASP) markers further validated these two QTLs and revealed that had less effect on TSPN than in 10-A×BE89 (134 RILs) and 10-A×Chuannong 16 (192 RILs) populations, and one population of Sichuan wheat (233 accessions). The alleles combination haplotype 3 with the allele from 10-A of and the allele from B39 of resulted in the highest number of spikelets. In contrast, the allele from B39 for both loci resulted in the lowest number of spikelets. Using bulk-segregant analysis-exon capture sequencing, six SNP hot spots that included 31 candidate genes were identified in the two QTLs. We identified from B39 and from 10-A and further analyzed variation in wheat. These results identified loci and molecular markers with potential utility for wheat breeding and laid a foundation for further fine mapping and cloning of the two loci.
小穗总数（TSPN）和可育小穗数（FSPN）影响小麦每个小穗的最终粒数。本研究利用55K单核苷酸多态性（SNP）芯片，从152个重组自交系（RIL）群体构建了高密度遗传图谱，该群体来源于小麦种质10 - A和B39的杂交。基于2019 - 2021年10个环境中的表型，定位了24个控制TSPN的数量性状位点（QTL）和18个控制FSPN的QTL。两个主要QTL，位于（34.43 - 47.43 Mb）和（32.97 - 34.43 Mb），解释了13.97% - 45.90%的表型变异。连锁竞争性等位基因特异性PCR（KASP）标记进一步验证了这两个QTL，并表明在10 - A×BE89（134个RIL）、10 - A×川农16（192个RIL）群体以及一个四川小麦群体（233份种质）中，对TSPN的影响小于。等位基因组合单倍型3，即来自的10 - A等位基因和来自的B39等位基因，产生的小穗数最多。相反，两个位点均来自B39的等位基因导致小穗数最少。利用混合分组分析法 - 外显子捕获测序，在这两个QTL中鉴定出6个包含31个候选基因的SNP热点区域。我们鉴定了来自B39的和来自10 - A的，并进一步分析了小麦中的变异。这些结果鉴定出了对小麦育种具有潜在应用价值的位点和分子标记，为进一步精细定位和克隆这两个位点奠定了基础。
