Genetic dissection of major QTL for grain number per spike on chromosomes 5A and 6A in bread wheat (Triticum aestivum L.)

Cheng Jiang; Zhibin Xu; Xiaoli Fan; Qiang Zhou; Guangsi Ji; Simin Liao; Yanlin Wang; Fang Ma; Yun Zhao; Tao Wang; Bo Feng

doi:10.3389/fpls.2023.1305547

Genetic dissection of major QTL for grain number per spike on chromosomes 5A and 6A in bread wheat (Triticum aestivum L.)

Front Plant Sci. 2024 Jan 8:14:1305547. doi: 10.3389/fpls.2023.1305547. eCollection 2023.

Authors

Cheng Jiang^{1

2

3}, Zhibin Xu¹, Xiaoli Fan¹, Qiang Zhou¹, Guangsi Ji^{1

3}, Simin Liao^{1

3}, Yanlin Wang^{1

3}, Fang Ma^{1

3}, Yun Zhao², Tao Wang^{1

4}, Bo Feng¹

Affiliations

¹ Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.
² College of Life Sciences, Sichuan University, Chengdu, China.
³ University of Chinese Academy of Sciences, Beijing, China.
⁴ The Innovative of Seed Design, Chinese Academy of Sciences, Beijing, China.

Abstract

Grain number per spike (GNS) is a crucial component of grain yield and plays a significant role in improving wheat yield. To identify quantitative trait loci (QTL) associated with GNS, a recombinant inbred line (RIL) population derived from the cross of Zhongkemai 13F10 and Chuanmai 42 was employed to conduct QTL mapping across eight environments. Based on the bulked segregant exome sequencing (BSE-Seq), genomic regions associated with GNS were detected on chromosomes 5A and 6A. According to the constructed genetic maps, two major QTL QGns.cib-5A (LOD = 4.35-8.16, PVE = 8.46-14.43%) and QGns.cib-6A (LOD = 3.82-30.80, PVE = 5.44-12.38%) were detected in five and four environments, respectively. QGns.cib-6A is a QTL cluster for other seven yield-related traits. QGns.cib-5A and QGns.cib-6A were further validated using linked Kompetitive Allele Specific PCR (KASP) markers in different genetic backgrounds. QGns.cib-5A exhibited pleiotropic effects on productive tiller number (PTN), spike length (SL), fertile spikelet number per spike (FSN), and ratio of grain length to grain width (GL/GW) but did not significantly affect thousand grain weight (TGW). Haplotype analysis revealed that QGns.cib-5A and QGns.cib-6A were the targets of artificial selection during wheat improvement. Candidate genes for QGns.cib-5A and QGns.cib-6A were predicted by analyzing gene annotation, spatiotemporal expression patterns, and orthologous and sequence differences. These findings will be valuable for fine mapping and map-based cloning of genes underlying QGns.cib-5A and QGns.cib-6A.

Keywords: BSE-Seq; QTL mapping; grain number per spike; haplotype analysis; wheat.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by the Sichuan Science and Technology Program, China (2022ZDZX0016), the West Light Foundation of the Chinese Academy of Sciences (2022XBZG_XBQNXZ_A_001), and the Major Science and Technology Achievement Transformation of Central Universities and Institutes in Sichuan Projects (2022ZHCG0131).