Quick mapping and characterization of a co-located kernel length and thousand-kernel weight-related QTL in wheat

https://link.springer.com/article/10.1007/s00122-022-04154-4

Theoretical and Applied Genetics，135，2849–2860 （2022）

Xiangru Qu,Cong Li,Hang Liu,Jiajun Liu,Wei Luo,Qiang Xu,Huaping Tang,Yang Mu,Mei Deng,Zhien Pu,Jun Ma,Qiantao Jiang,Guoyue Chen,Pengfei Qi,Yunfeng Jiang,Yuming Wei,Youliang Zheng,Xiujin Lan &Jian Ma

Key message

A co-located KL and TKW-related QTL with no negative effect on PH and AD was rapidly identified using BSA and wheat 660 K SNP array. Its effect was validated in a panel of 218 wheat accessions.

Abstract

Kernel length (KL) and thousand-kernel weight (TKW) of wheat (Triticum aestivumL.) contribute significantly to kernel yield. In the present study, a recombinant inbred line (RIL) population derived from the cross between the wheat line S849-8 with larger kernels and more spikelets per spike and the line SY95-71 was developed. Further, of both the bulked segregant analysis (BSA) and the wheat 660 K single nucleotide polymorphism (SNP) array were used to rapidly identify genomic regions for kernel-related traits from this RIL population. Kompetitive Allele Specific PCR markers were further developed in the SNP-enriched region on the 2D chromosome to construct a genetic map. BothQKL.sicau-SSY-2Dfor KL andQTKW.sicau-SSY-2Dfor TKW were identified at multiple environments on chromosome arm 2DL. These two QTLs explained 9.68–23.02% and 6.73–18.32% of the phenotypic variation, respectively. The effects of this co-located QTL were successfully verified in a natural population consisting of 218 Sichuan wheat accessions. Interestingly, the major QTL was significantly and positively correlated with spike length, but did not negatively affect spikelet number per spike (SNS), plant height, or anthesis date. These results indicated that it is possible to synchronously improve kernel weight and SNS by using this QTL. Additionally, several genes associated with kernel development and filling rate were predicted and sequenced in the QTL-containing physical intervals of reference genomes of ‘Chinese spring’ andAegilops tauschii. Collectively, these results provide a QTL with great breeding potential and its linked markers which should be helpful for fine mapping and molecular breeding.