TITLE:
Genome Wide Association Study of Yield and Yield-Related Traits in Elite Spring Bread Wheat Genotypes Grown under High Temperature Environment in Sudan
AUTHORS:
Elfadil M. E. Elbashier, Siddig E. Idris, Izzat S. A. Tahir, Samira Elhanafi, Abu Sefyan I. Saad, Hala M. Mustafa, Amani A. Idris, Wuletaw Tadesse
KEYWORDS:
Wheat, High Temperature, Tolerance, Genome, Chromosome, Marker, Phenotyping and Genotyping
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.14 No.2,
February
28,
2023
ABSTRACT: Genetic improvement of wheat for heat tolerance is the main breeding
objective in Sudan as it is the principal limiting factor for wheat production.
To this end, the availability of wheat genetic diversity is key for success.
Genetic diversities and genome-wide association studies were conducted to parse
the complex genetic composition of yield-related traits of 250 bread wheat
genotypes which were selected from ICARDA’s advanced materials. The genotypes
were evaluated under heat stress environment for two seasons (2016/17 and 2017/18)
in two sowing dates (optimum and late) at the Gezira Research Farm (GRF), of the Agricultural Research
Corporation (ARC), Wad Medani, Sudan. Yield levels ranged from 4016 - 5120
kg/ha for optimum and late sowing dates respectively in the first season and
from 5386 - 3926 kg/ha for optimum and late sowing dates respectively in the second
season. The top 20 genotypes were better than the best check in the two seasons
except, Imam which ranked number 18 in the second season. Two genotypes,
genotypes 27 and 37, produced high grain yield in both seasons. Wide ranges of
variations among genotypes were found for yield and yield-related traits,
including days to heading and maturity,
plant height, number of seeds/spike, 1000 seed weight, biomass and harvest index.
Genome wide association analyses were performed using 15 kSNPmarkers and the phenotypic data. A total of
282, 355 and 475 significant (P served in the first season, second
season and across seasons, respectively. Markers (6B/Kukri_ c27662, 6B/.BobWhite_c23771_525, 6B/Excalibur_c32219_491,
6B/RAC875_c31299_13021302, 6B/BS00046264_51,6A/wsnp_Ex_rep_c69373_68312188, 6A/Tdurum contig12123_1650, 6BKukri_c27662_675 and 6A/BobWhite_c15802_72) on chromosomes 6B and 6A for
grain yield were highly significantly associated and stable in every season and across seasons. Highly significant
Marker-traits associations (MTAs) were observed for many traits
including days to heading and maturity, plant height, number of seeds/spike,
1000 seed weight, biomass and harvest index. The currently identified MTAs
should be further validated using other elite sets of genotypes so that they
can be used for MAS in the breeding program. The high yielding and heat tolerant
genotypes identified in this study will be evaluated across key locations in
Sudan for potential release in Sudan. Furthermore, they will be used as parents
in the breeding program for heat tolerance.