DOI: 10.5061/dryad.qnk98sfkw
title: Dataset for: Identification of genomic regions of wheat associated with grain Fe and Zn content under drought and heat stress using genome-wide association study

description: The study material in the GWAS panel with 282 advanced breeding lines of
 bread wheat genotypes from IARI stress breeding program was selected to
 map the genomic regions responsible for grain iron and Zinc content under
 drought and heat stress treatments. Phenotypic data: The GWAS panel was
 evaluated at IARI, New Delhi - DL (28.6550° N, 77.1888° E, MSL 228.61 m)
 under Irrigated (IR), Restricted Irrigated (RI) and Late sown (LS)
 treatment conditions with augmented RCBD design. Data was collected on
 Grain Iron and Grain zinc content along with thousand-grain weight. Around
 20 g of grain sample from each of 282 genotypes from the GWAS panel under
 all three conditions were used for phenotyping GFeC and GZnC through
 high-throughput Energy Dispersive X-ray Fluorescence (ED-XRF) machine
 (model X-Supreme 8000; Oxford Instruments plc, Abingdon, United Kingdom)
 calibrated with glass beads-based values. To record TGW, manual counting
 of grains was followed and the weight of the grains was recorded in grams
 with an electronic balance. 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 &lt;5%, missing data of &gt;20%, and heterozygote
 frequency &gt;25% were removed from the analysis. The remaining set of
 10546 high-quality SNPs was used in GWAS analysis.
description: All the materials were
 evaluated at IARI New Delhi (Indian Agricultural Research Institute,
 research farm located 28°38′30.5″N, 77°09′58.2″E, 228 m AMSL) with three
 conditions viz., Timely sown irrigated (IR), Timely sown Drought (RI) and
 Late sown condition (LS). A total of 6 irrigations was given for the
 irrigated and late sown trials. Whereas one irrigation before and one
 after the sowing was provided for restricted irrigated trials. IR and RI
 trials were sown on the first fortnight of November whereas LS trials was
 sown in second fortnight of December to expose plants to the natural heat
 in later growing periods. Experiment was conducted in Augmented RCBD
 design with four checks and six blocks with plot size of 1 m2
 each. Phenotyping Twenty random spikes from each line
 were collected in clean polyethylene bags and hand threshed. Grain Fe and
 Zn contents (in mg/Kg) were estimated with 20 gram seeds of each line
 through high-throughput Energy Dispersive X-ray Fluorescence (ED-XRF)
 machine (model X-Supreme 8000; Oxford Instruments plc, Abingdon, United
 Kingdom) calibrated with glass beads based values (Paltridge et al.,
 2012). Thousand kernel weight was measured by manual counting. The GWAS
 panel under all the three conditions were phenotyped for GFeC, GZnC and
 TGW. Phenotypic data were analysed using the r package ‘augmentedRCBD’
 (Aravind et al. 2021) for ANOVA and adjusted means for each genotype under
 study. The z test was used to compare the statistically significant
 differences between control and treatment means.