Dissection of Superior Alleles for Yield-Related Traits and Their Distribution in Important Cultivars of Wheat by Association Mapping

Abstract

Uncovering the genetic basis of yield-related traits is important for molecular improvement of wheat cultivars. In this study, a genome-wide association study was conducted using the wheat 55K genotyping assay and a diverse panel of 384 wheat genotypes. The accessions used included 18 founder parents and 15 widely grown cultivars with annual maximum acreages of over 667,000 ha, and the remaining materials were elite cultivars and breeding lines from several major wheat ecological areas of China. Field trials were conducted in five major wheat ecological regions of China over three consecutive years. A total of 460 significant loci were detected for eight yield-related traits. Forty-five superior alleles distributed over 31 loci for which differences in phenotypic values grouped by single nucleotide polymorphism (SNP) reached significant levels (P < 0.05) in nine or more environments, were detected; some of these loci were previously reported. Eleven of the 31 superior allele loci on chromosomes 4A, 5A, 3B, 5B, 6B, 7B, 5D, and 7D had pleiotropic effects. For example, AX-95152512 on 5D was simultaneously related to increased grain weight per spike (GWS) and decreased plant height (PH); AX-109860828 on 5B simultaneously led to a high 1,000-kernel weight (TKW) and short PH; and AX-111600193 on 4A was simultaneously linked to a high TKW and GWS, and short PH. The favorable alleles in each accession ranged from 2 to 30 with an average of 16 at the thirtyone loci in the population, and six accessions (Zhengzhou683, Suzhou7829, Longchun7, Ningmai6, Yunmai35 and Zhen7630) contained more than 27 favorable alleles. A significant association between the number of favorable alleles and yield was observed (r = 0.799, p < 0.0001), suggesting that pyramiding multiple QTL with marker-assisted selection may effectively increase yield of wheat. Furthermore, distribution of superior alleles in founder parents and widely grown cultivars was also discussed here. This study is useful for marker-assisted selection for yield improvement and dissecting the genetic mechanism of important cultivars in wheat.

Dissection of Genetic Basis Underpinning Kernel Weight-Related Traits in Common Wheat

“…Rapid and high-efficiency genotyping greatly accelerate the discovery of genetic loci for wheat. Up to now, a number of loci associated with grain weight have been identified on 21 chromosomes of wheat based on the linkage mapping approach and genome-wide associated study (GWAS) approach [5,15,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]. Some major quantitative trait loci (QTLs) were developed to do fine mapping in a previous study.…”

Haplotype-Based, Genome-Wide Association Study Reveals Stable Genomic Regions for Grain Yield in CIMMYT Spring Bread Wheat

“…Although high-density markers, such as genotyping-bysequencing (GBS) or SNP arrays, have been used extensively in wheat to explore the genetic architecture of GY and yield components using GWAS (Neumann et al, 2011;Zhang et al, 2013;Edae et al, 2014;Ain et al, 2015;Azadi et al, 2015;Lopes et al, 2015;Sukumaran et al, 2015;Sehgal et al, 2016;Qaseem et al, 2018;Garcia et al, 2019;Li et al, 2019Li et al, , 2020Ward et al, 2019;Shokat et al, 2020), panel sizes have been relatively small to dissect such a complex trait, and results therefore were quite variable, identifying hundreds of small-effect QTL. GWAS reports in larger germplasm panels are still rare (Sehgal et al, 2017(Sehgal et al, , 2020Juliana et al, 2019).…”

Multi-model genome-wide association and genomic prediction analysis of 16 agronomic, physiological and quality related traits in ICARDA spring wheat

“…Grain yield is an outcome from an aggregation of several agronomic and physiological traits (Chen et al 2012;Sukumaran et al 2018;Tshikunde et al 2019;Jamil et al 2019). Agronomic traits for attention include grain number per spike, thousand kernel weight, above-ground biomass, plant height, whereas important phenological traits include heading and maturity dates as the grain filling period under specific seasonal conditions has an enormous effect on final grain yield (Reif et al 2011b;Ihsan et al 2016;Sun et al 2017;Wang et al 2017;Ma et al 2018;Liu et al 2018;Li et al 2020). Drought and heat stresses are the two most important environmental constraints that curtail wheat production globally.…”