Abstract
BackgroundClimate change, including higher temperatures (HT) has a detrimental impact on wheat productivity and modeling studies predict more frequent heat waves in the future. Wheat growth can be impaired by high daytime and nighttime temperature at any developmental stage, especially during the grain filling stage. Leaf chlorophyll content, leaf greenness, cell membrane thermostability, and canopy temperature have been proposed as candidate traits to improve crop adaptation and yield potential of wheat under HT. Nonetheless, a significant gap exists in knowledge of genetic backgrounds associated with these physiological traits. Identifying genetic loci associated with these traits can facilitate physiological breeding for increased yield potential under high temperature stress condition in wheat.ResultsWe conducted genome-wide association study (GWAS) on a 236 elite soft wheat association mapping panel using 27,466 high quality single nucleotide polymorphism markers. The panel was phenotyped for three years in two locations where heat shock was common. GWAS identified 500 significant marker-trait associations (MTAs) (p ≤ 9.99 × 10− 4). Ten MTAs with pleiotropic effects detected on chromosomes 1D, 2B, 3A, 3B, 6A, 7B, and 7D are potentially important targets for selection. Five MTAs associated with physiological traits had pleiotropic effects on grain yield and yield-related traits. Seventy-five MTAs were consistently expressed over several environments indicating stability and more than half of these stable MTAs were found in genes encoding different types of proteins associated with heat stress.ConclusionsWe identified 500 significant MTAs in soft winter wheat under HT stress. We found several stable loci across environments and pleiotropic markers controlling physiological and agronomic traits. After further validation, these MTAs can be used in marker-assisted selection and breeding to develop varieties with high stability for grain yield under high temperature.
Highlights
Climate change, including higher temperatures (HT) has a detrimental impact on wheat productivity and modeling studies predict more frequent heat waves in the future
soil-plant analyses development (SPAD) was positively correlated with membrane thermostability (MT) (0.31***), Grain yield (GY) (0.50***), spike fertility (SF) (0.25***), grain number (GN) (0.30***), harvest index (HI) (0.46***), spike harvest index (SHI) (0.37***) and thousand grain weight (TGW) (0.26***) (Additional file 4)
MT was positively correlated with NDVI was measured at anthesis (NDVIa) (0.22***), normalized difference vegetation index at grain filling (NDVIg) (0.31***), GY (0.60***), SF (0.29***), GN (0.33***), HI (0.58***), SHI (0.44***) and TGW (0.40***)
Summary
Climate change, including higher temperatures (HT) has a detrimental impact on wheat productivity and modeling studies predict more frequent heat waves in the future. Wheat growth can be impaired by high daytime and nighttime temperature at any developmental stage, especially during the grain filling stage. Leaf greenness, cell membrane thermostability, and canopy temperature have been proposed as candidate traits to improve crop adaptation and yield potential of wheat under HT. Identifying genetic loci associated with these traits can facilitate physiological breeding for increased yield potential under high temperature stress condition in wheat. High temperature (HT) stress is one of the major consequences of climate change and poses a serious threat to wheat production [4]. Post-anthesis heat stress is very common in wheat growing areas and can cause large reductions in grain yield [7]. Some researchers suggest that HDT and HNT cause damage of a similar magnitude to winter wheat [8], others report a stronger negative impact on yield of HNT compared to HDT [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
