Genome‐wide association studies identify putative pleiotropic locus mediating drought tolerance in sorghum

Abstract

Drought is a key constraint on plant productivity and threat to food security. Sorghum (Sorghum bicolor L. Moench), a global staple food and forage crop, is among the most drought-adapted cereal crops, but its adaptation is not yet well understood.This study aims to better understand the genetic basis of preflowering drought in sorghum and identify loci underlying variation in water use and yield components under drought. A panel of 219 diverse sorghum from West Africa was phenotyped for yield components and water use in an outdoor large-tube lysimeter system under well-watered (WW) versus a preflowering drought water-stressed (WS) treatment.The experimental system was validated based on characteristic drought response in international drought tolerant check genotypes and genome-wide association studies (GWAS) that mapped the major height locus at QHT7.1 and Dw3. GWAS further identified marker trait associations (MTAs) for drought-related traits (plant height, flowering time, forage biomass, grain weight, water use) that each explained 7-70% of phenotypic variance. Most MTAs for drought-related traits correspond to loci not previously reported, but some MTA for forage biomass and grain weight under WS co-localized with staygreen post-flowering drought tolerance loci (Stg3a and Stg4). A globally common allele at S7_50055849 is associated with several yield components under drought, suggesting that it tags a major pleiotropic variant controlling assimilate partitioning to grain versus vegetative biomass. The GWAS revealed oligogenic variants for drought tolerance in sorghum landraces, which could be used as trait predictive markers for improved drought adaptation.

Global Trends and Future Works in Sorghum Research: A Combined Bibliometric and Content Analysis Approach

“…Sorghum has become increasingly popular for diverse applications, including food [1][2][3], feed [4][5][6], and bioenergy [7][8][9]. Its widespread cultivation is attributed to its remarkable adaptability and drought tolerance, making it well-suited for changing climates [10,11]. Additionally, sorghum stands out for its high productivity, minimal nutrient requirements, and cost-effectiveness, making it a competitive crop globally, especially in regions like Africa and Asia [5,12,13].…”

Genome-Wide Association Study Based on Plant Height and Drought-Tolerance Indices Reveals Two Candidate Drought-Tolerance Genes in Sweet Sorghum

“…With the rapid development of molecular biology, molecular genetics and bioinformatics, genome-wide association studies (GWASs), based on the natural population and linkage disequilibrium, can detect genetic variation polymorphisms in the whole genome and conduct population-level statistical analysis of the genotype and phenotype, which can efficiently detect genes associated with traits, making it more convenient to mine genes that control the drought-tolerance traits of crops and identify excellent genetic variation materials. With the reduction in sequencing costs and the completion of most crop gene sequencing, GWASs have been widely applied in the drought-tolerance research of rice [4][5][6][7][8], wheat [9][10][11][12], maize [13][14][15], soybean [16,17], sorghum [18,19], cotton [20] and other crops, and many significant marker-trait association loci and candidate genes related to drought tolerance have been revealed, some of which are related to transcription factors (TFs) [7,8,10,16,18]. The quantitative trait locus identified by GWAS contains candidate genes with functions related to osmotic stress regulation, such as the basic leucine zipper (bZIP) protein gene OsbZIP80, which plays an important role in the tolerance of or adaptation to abiotic stress and is considered a rice-dehydration stress-inducible gene [8].…”