Genome-wide association mapping for component traits of drought and heat tolerance in wheat

The study material in GWAS panel with 282 advanced breeding line of bread
wheat genotypes from IARI stress breeding program was selected to map the
genomic regions responsible for Drought and heat tolerance component
traits. Phenotypic data: The GWAS panel was evaluated at multiple
locations namely, IARI, New Delhi - DL (28.6550° N, 77.1888° E, MSL 228.61
m), ARI, Pune - PUNE (18.5204° N, 73.8567° E, MSL 560m), IIWBR, Karnal -
IIWBR (29.6857° N, 76.9905°E, MSL 243m), IARI, Jharkhand - JR (24.1929° N,
85.3756° E, MSL 580m) and IARI RS, Indore - IND (22.7196° N, 75.8577° E,
MSL 553 m) with augmented RCBD design. Three tratments viz, IR
(Irrigated), RI (Restricted irrigated) and LS (Late sown) were imposed for
control, drought and heat stress, respectively.  Data was
collected on traits like Days to heading (DH), Days to maturity (DM),
Normalized Difference Vegetation Index (NDVI) at anthesis and grain
filling stage, chlorophyll content (SPAD) of flag leaf at post anthesis
stage, Plant height (PH), Canopy temperature (CT), Grain weight per spike
(GWPS), Thousand Grain weight (TGW), Plot Yield (PLTY) and Biomass.
Genotypic data: Genomic DNA of the GWAS panel was extracted from the
leaves of seedlings by Cetyl Trimethyl Ammonium Bromide (CTAB) method. The
panel was genotyped using Axiom Wheat Breeder’s Genotyping Array
(Affymetrix, Santa Clara, CA, United States) having 35,143 genome-wide
SNPs. The monomorphic, markers with minor allele frequency (MAF) of
<5%, missing data of >20%, and heterozygote frequency
>25% were removed from the analysis. The remaining set of 10546
high-quality SNPs was used in GWAS analysis. The detailed information of
the methods and software used, data analysis and GWAS is provided at doi:
10.3389/fpls.2022.943033