A novel allele of TaGW2-A1 is located in a finely mapped QTL that increases grain weight but decreases grain number in wheat (Triticum aestivum L.)

Abstract

Key messageA novel TaGW2-A1 allele was identified from a stable, robust QTL region, which is pleiotropic for thousand grain weight, grain number per spike, and grain morphometric parameters in wheat.AbstractThousand grain weight (TGW) and grain number per spike (GNS) are two crucial determinants of wheat spike yield, and genetic dissection of their relationships can help to fine-tune these two components and maximize grain yield. By evaluating 191 recombinant inbred lines in 11 field trials, we identified five genomic regions on chromosomes 1B, 3A, 3B, 5B, or 7A that solely influenced either TGW or GNS, and a further region on chromosome 6A that concurrently affected TGW and GNS. The QTL of interest on chromosome 6A, which was flanked by wsnp_BE490604A_Ta_2_1 and wsnp_RFL_Contig1340_448996 and designated as QTgw/Gns.cau-6A, was finely mapped to a genetic interval shorter than 0.538 cM using near isogenic lines (NILs). The elite NILs of QTgw/Gns.cau-6A increased TGW by 8.33%, but decreased GNS by 3.05% in six field trials. Grain Weight 2 (TaGW2-A1), a well-characterized gene that negatively regulates TGW and grain width in wheat, was located within the finely mapped interval of QTgw/Gns.cau-6A. A novel and rare TaGW2-A1 allele with a 114-bp deletion in the 5′ flanking region was identified in the parent with higher TGW, and it reduced TaGW2-A1 promoter activity and expression. In conclusion, these results expand our knowledge of the genetic and molecular basis of TGW-GNS trade-offs in wheat. The QTLs and the novel TaGW2-A1 allele are likely useful for the development of cultivars with higher TGW and/or higher GNS.Electronic supplementary materialThe online version of this article (10.1007/s00122-017-3017-y) contains supplementary material, which is available to authorized users.

Uncovering the Genetic Architecture of Fruiting Efficiency in Bread Wheat: A Viable Alternative to Increase Yield Potential

“…Related genomic regions associated with grain yield, GNS, and TKW have been previously reported in almost the entire wheat genome (Deng et al, 2011; Cui et al, 2012; Deng et al, 2017; Guo et al, 2017; Sun et al, 2017; Zou et al, 2017; Liu et al, 2018; Su et al, 2018; Yu et al, 2018; Zhai et al, 2018). In this study, we found significant SNPs markers on 2A, 2B, and 7A for GWS; on 1B, 2A, 2B, and 7A for TKW; and on 1A, 2B, and 2D for GNS.…”

Global QTL Analysis Identifies Genomic Regions on Chromosomes 4A and 4B Harboring Stable Loci for Yield-Related Traits Across Different Environments in Wheat (Triticum aestivum L.)

“…TGW and GNS are two crucial but counteracting determinants of wheat grain yield (Quarrie et al, 2006 ; Schulthess et al, 2017 ; Zhai et al, 2017 ). In the present study, we identified two stable QTL on chromosome 4A controlling TGW ( QTgw.cau-4A.3 ) and GNS ( QGns.cau-4A.4 ) with superior alleles coming from the opposite parent (Table 5 ), which exhibited a strong pleiotropic trade-off between TGW and GNS, consistent with phenotypic correlation analysis (Table 4 ).…”

“…Briefly, these cloned rice genes for grain size are mainly involved in multiple signaling pathways, including ubiquitination-mediated proteasomal degradation, phytohormones, and G protein signaling, to regulate cell division and cell expansion (Zuo and Li, 2014 ; Li and Yang, 2017 ). In wheat, a wealth of QTL for grain weight have been identified to date on almost all wheat chromosomes based on linkage mapping in bi-parental genetic populations and genome-wide association study (GWAS), and a number of genes associated with grain weight have been isolated using comparative genetic analysis (Quarrie et al, 2005 ; Zhang et al, 2010 ; Liu G. et al, 2014 ; Gao et al, 2015 ; Zanke et al, 2015 ; Li and Yang, 2017 ; Nadolska-Orczyk et al, 2017 ; Sajjad et al, 2017 ; Shao et al, 2017 ; Zhai et al, 2017 ). Nonetheless, to the best of our knowledge, there are no reports of cloned major QTL for grain weight through map-based cloning approach in wheat, and the molecular roles of QTL/genes in the regulation of grain weight are still largely unknown.…”

QTL mapping for flag leaf-related traits and genetic effect of QFLW-6A on flag leaf width using two related introgression line populations in wheat

“…Phenotypic differences between lines and the recipient parent can generally be attributed to substituted fragments from donor [36,41]. Backcross introgression has been the most commonly used method for developing NILs for QTL studies [54][55][56][57][58]. In the present study, the target QTLs were tracked with SSR markers.…”