Identification of the candidate gene controlling tiller angle in common wheat through genome-wide association study and linkage analysis

Wheat tiller angle (TA) is an important agronomic trait that contributes to grain production by affecting plant architecture. It also plays a crucial role in high-yield wheat breeding. An association panel and a recombinant inbred line (RIL) population were used to map quantitative trait loci (QTL) for TA. Results showed that 470 significant SNPs with 10.4%-28.8% phenotypic variance explained (PVE) were detected in four replicates by a genome-wide association study (GWAS). Haplotype analysis showed that the TA_Hap_4B1 locus on chromosome 4B was a major QTL to regulate wheat TA. Ten QTL were totally detected by linkage mapping with the RIL population, and QTA.hau-4B.1 identified in six environments with the PVE of 7.88%-18.82% was a major and stable QTL. A combined analysis demonstrated that both TA_Hap_4B1 and QTA.hau-4B.1 were co-located on the same region. Moreover, QTA.hau-4B.1 was con-firmed by bulked segregant RNA-Seq (BSR-Seq) analysis. Phenotypic analysis showed that QTA.hau-4B.1 was also closely related to yield traits. Furthermore, TraesCS4B02G049700 was considered as a candidate gene through analysis of gene sequence and expression. This study can be potentially used in cloning key genes modulating wheat tillering and provides valuable genetic resources for improvement of wheat plant architecture.& COPY; 2022 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. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

In this study, the important gene region regulating wheat tiller angle was identified through association and linkage analysis. The results showed that the TA_Hap_4B1 and QTA.hau-4B.1 genes were located in the same region and closely related to yield traits. This research is of great significance for improving wheat plant architecture and cloning related genes.