Abstract:
Genome-wide association studies (GWAS) were undertaken to detect SNP
markers related with physiological, biochemical and yield traits in 92 genotypes
from Pakistani historical set and synthetic hexaploid wheat collections. The field
experiment was conducted during 2013–2015 seasons under controlled and
drought conditions. Genotyping was done using high-density Illumina iSelect 15K
SNP (single nucleotide polymorphism) array, and finally 7739 high quality SNPs
were used in mapping. Population structure analysis identified two subpopulations
(K = 2) that were representative of synthetic hexaploids and local cultivars of
Pakistan. LD decay was observed at 11cM genetic distance for whole genome
collection using 700 unlinked markers. In total, there were 1174 MTAs recorded
for biochemical parameters at P<0.001 in stressed conditions using MLM
approach, among them, 647 MTAs were flanked for more then one trait. Genome
A, B and D contributed 431, 553 and 190 MTAs respectively. Highest number of
MTAs were found on chromosome 2B. For yield components, out of 1035
markers, 274 were confined to a single trait. Highest number of MTAs were
located on genome B (534), followed by genome A (406) and D (95). Trait wise
number of MTAs were for PH(84), TGW(138), SL(106), GPS(147), DH(118),
DPM(97), GL(143), PUB(89), Habit(52) and LR(61). Based upon this research,
future breeding strategies can be conceived to start marker assisted breeding for
manipulating favorable alleles of SNPs associated with drought related attributes to
increase grain yield in stressed environments.
