Heat‐Tolerant QTLs Associated with Grain Yield and Its Components in Spring Bread Wheat under Heat‐Stressed Environments of Sudan and Egypt

Abstract

Heat stress decreases photosynthesis, pollen viability, and grain number and weight and hence lowers yield and quality of wheat (Triticum aestivum L.) by variable amounts among different cultivars and genotypes. The present study was performed to determine genetic variability of spring bread wheat genotypes for yield and other agronomic traits under heat‐stressed (Wad Medani, Sudan) and high‐yielding (Sids, Egypt) environments and to identify linked single nucleotide polymorphism (SNP) markers through association mapping. A heat association panel of 197 spring wheat genotypes from ICARDA was evaluated for yield and agronomic traits at Wad Medani and Sids stations for 2 yr (2014–2015). A total of 111 significant marker‐trait associations were detected. The wsnp_Ex_c12812_20324622 marker on chromosome 4A was significantly correlated with yield at both locations. At Wad Medani, wsnp_Ex_c2526_4715978 on chromosome 5A was significantly correlated with grain yield. Wheat genotypes carrying the cytosine base at the wsnp_Ex_c12812_20324622 and wsnp_Ex_c2526_4715978 markers outyielded the ones carrying the alternative bases by 15%, whereas genotypes carrying the cytosine base at only one of the two markers increased their yield by 7.9 to 10%, suggesting the importance of using these markers for marker‐assisted selection in breeding programs to increase yield under heat stress. The top 20 high‐yielding and heat‐tolerant genotypes identified in this study have been distributed to the national research systems of Central and West Asia and North Africa (CWANA) and sub‐Saharan Africa (SSA) for potential direct release and/or use as parents after local adaptation trials.

Genetic Characterization and Genome-Wide Association Mapping for Stem Rust Resistance in Spring Bread Wheat

“…Based on previous studies on common wheat in Ethiopia, an average PIC of 2_3 and average gene diversity of 3_4 were reported in various wheat collections [32][21] [33]. Overall, our results revealed the influence of selection pressures on our breeding lines genetic diversity.…”

Identification and Characterization of Contrasting Genotypes/Cultivars for Developing Heat Tolerance in Agricultural Crops: Current Status and Prospects

“…Wheat genotypes carrying the cytosine base at the wsnp_Ex_c12812_20324622 and wsnp_Ex_c2526_4715978 markers produced more yield, compared to those carrying the alternative bases, by 15%, indicating the significance of involving these markers for marker-assisted selection in breeding programs to increase yield under heat stress. The best performing 20 high-yielding as well as heat-tolerant wheat genotypes, found in this study, have been distributed across Central and West Asia and North Africa (CWANA) and sub-Saharan Africa (SSA) for potential direct release and/or use as parents after local adaptation trials (Tadesse et al, 2019).…”

“…Large scale DNA-based marker development during the last decade led to mapping of QTLs linked to heat tolerance in various crops (Jha et al, 2014;Janni et al, 2020). Advances in sequencing technologies especially, next generation sequencing (NGS), genotyping by sequencing (GBS), and other high throughput genotyping platforms have facilitated narrowing down of the heat tolerance QTL regions for analysis of candidate genes (Xu et al, 2017;Kilasi et al, 2018;Inghelandt et al, 2019;Tadesse et al, 2019). Given the huge number of novel SNPs developed recently and GWAS in large set of global crop germplasm, it became possible to identify novel haplotypes/genomic regions controlling heat tolerance (Paul et al, 2018;Varshney et al, 2019;Khan et al, 2020;Weckwerth et al, 2020) and allowed for the assessment of genetic diversity at nucleotide-scale.…”

Exploitation of Tolerance of Wheat Kernel Weight and Shape-Related Traits from Aegilops tauschii under Heat and Combined Heat-Drought Stresses

“…Heat (H) and heat-drought (HD) conditions: the lines were grown at the Gezira Research Farm (GRF), Agricultural Research Corporation (ARC), Wad Medani, Sudan (14°24′ N, 29°33 ′E, 407 m asl), in the 2017/18 season from November to March. We selected GRF because it is recognized as the global center for heat-tolerance research [56,57]. The ARC manages it in collaboration with CIMMYT, ICARDA and Tottori University, Japan (SATREPS Project).…”