Genetic dissection of drought and heat‐responsive agronomic traits in wheat

Abstract

High yield and wide adaptation are principal targets of wheat breeding but are hindered by limited knowledge on genetic basis of agronomic traits and abiotic stress tolerances. In this study, 277 wheat accessions were phenotyped across 30 environments with non‐stress, drought‐stressed, heat‐stressed, and drought‐heat‐stressed treatments and were subjected to genome‐wide association study using 395 681 single nucleotide polymorphisms. We detected 295 associated loci including consistent loci for agronomic traits across different treatments and eurytopic loci for multiple abiotic stress tolerances. A total of 22 loci overlapped with quantitative trait loci identified by biparental quantitative trait loci mapping. Six loci were simultaneously associated with agronomic traits and abiotic stress tolerance, four of which fell within selective sweep regions. Selection in Chinese wheat has increased the frequency of superior marker alleles controlling yield‐related traits in the four loci during past decades, which conversely diminished favourable genetic variation controlling abiotic stress tolerance in the same loci; two promising candidate paralogous genes colocalized with such loci, thereby providing potential targets for studying the molecular mechanism of stress tolerance–productivity trade‐off. These results uncovering promising alleles controlling agronomic traits and/or multiple abiotic stress tolerances, providing insights into heritable covariation between yield and abiotic stress tolerance, will accelerate future efforts for wheat improvement.

RING finger ubiquitin E3 ligase gene TaSDIR1-4A contributes to determination of grain size in common wheat

“…The rainfalls were 131 mm in the 2010–2011 growing season, 180 mm in 2011–2012, 158 mm in 2012–2013, 161 mm in 2015–2016, and 173 mm in 2016–2017. A heat-stress (HS) treatment was applied 1 week post-anthesis at Shunyi by positioning a plastic film supported by steel frames over the plots in the field ( Li et al , 2019 a ). Populations 3 and 4 were planted in three environments, at Luoyang (34°610′N; 112°450′E) in Henan province in 2002 and 2005, and at Shunyi in 2010.…”

Recent Progress in Germplasm Evaluation and Gene Mapping to Enable Breeding of Drought-Tolerant Wheat

“…By employing the above genetic diversity, conventional linkage mapping, using biparental populations and double haploid lines, has commonly been used to locate QTLs/genes associated with target traits, including those associated with drought (Sallam et al, 2016;Zhao et al, 2018;Li L. et al, 2019). The objective of these studies is to facilitate marker/genome assisted selection.…”

Functional genomic approaches to improve crop plant heat stress tolerance

“…GWAS emerged as a powerful tool to identify the genetic basis behind complex phenotypic traits 15, 16 , and it provides high mapping resolution compared with conventional genetic mapping 17, 18 . So far this approach has been applied to major food crops, including wheat 7, 19, 20 , rice 21 , maize 22 , sorghum 23 and Brassica napus L. 24 , to identify the natural variation associated with heat stress and to understand this genetic basis. Another way to identify and understand the key molecular mechanisms in response to heat stress is a transcriptomic study 25, 26 ; plants respond to heat stress by inducing various heat responsive genes, thus transcriptomic studies provide an effective screening of heat responsive candidate genes 6 .…”