A major QTL simultaneously increases the number of spikelets per spike and thousand-kernel weight in a wheat line

https://link.springer.com/article/10.1007/s00122-023-04459-y

Theoretical and Applied Genetics,volume 136, Article number: 213 (2023)

Conghao Zhao,Jieguang Zhou,Cong Li,Jianing You,Yanling Liu,Huaping Tang,Mei Deng,Qiang Xu,Yazhou Zhang,Qiantao Jiang,Guoyue Chen,Pengfei Qi,Yunfeng Jiang,Jirui Wang,Wei Li,Zhien Pu,Guangdeng Chen,Yun Jiang,Zhi Zheng,Chunji Liu,Youliang Zheng,Yuming Wei*,Jian Ma*

Abstract

Spikelet number per spike (SNS) is an important determinant of yield in wheat. In the present study, we combined bulked segregant analysis (BSA) and the wheat 660 K single-nucleotide polymorphism (SNP) array to rapidly identify genomic regions associated with SNS from a recombinant inbred line (RIL) population derived from a cross between the wheat lines S849-8 and SY95-71. A genetic map was constructed using Kompetitive Allele Specific PCR markers in the SNP-enriched region on the long arm of chromosome 7A. A major and stably expressed QTL, QSNS.sicau-SSY-7A, was detected in multiple environments. It was located in a 1.6 cM interval on chromosome arm 7AL flanked by the markers AX-109983514andAX-109820548. This QTL explained 6.86–15.72% of the phenotypic variance, with LOD values ranging from 3.66 to 8.66. Several genes associated with plant growth and development were identified in the interval where QSNS.sicau-SSY-7A was located on the ‘Chinese Spring’ wheat and wild emmer reference genomes. Furthermore, the effects of QSNS.sicau-SSY-7A andWHEAT ORTHOLOG OFAPO1(WAPO1)on SNS were analyzed. Interestingly,QSNS.sicau-SSY-7A significantly increased SNS without negative effects on thousand-kernel weight, anthesis date and plant height, demonstrating its great potential for breeding aimed at improving grain yield. Taken together, these results indicate that QSNS.sicau-SSY-7A is a promising locus for yield improvement, and its linkage markers are helpful for fine mapping and molecular breeding.