Genetic dissection of drought and heat tolerance in chickpea through genome-wide and candidate gene-based association mapping approaches

PLoS One. 2014 May 6;9(5):e96758. doi: 10.1371/journal.pone.0096758. eCollection 2014.

Abstract

To understand the genetic basis of tolerance to drought and heat stresses in chickpea, a comprehensive association mapping approach has been undertaken. Phenotypic data were generated on the reference set (300 accessions, including 211 mini-core collection accessions) for drought tolerance related root traits, heat tolerance, yield and yield component traits from 1-7 seasons and 1-3 locations in India (Patancheru, Kanpur, Bangalore) and three locations in Africa (Nairobi, Egerton in Kenya and Debre Zeit in Ethiopia). Diversity Array Technology (DArT) markers equally distributed across chickpea genome were used to determine population structure and three sub-populations were identified using admixture model in STRUCTURE. The pairwise linkage disequilibrium (LD) estimated using the squared-allele frequency correlations (r2; when r2<0.20) was found to decay rapidly with the genetic distance of 5 cM. For establishing marker-trait associations (MTAs), both genome-wide and candidate gene-sequencing based association mapping approaches were conducted using 1,872 markers (1,072 DArTs, 651 single nucleotide polymorphisms [SNPs], 113 gene-based SNPs and 36 simple sequence repeats [SSRs]) and phenotyping data mentioned above employing mixed linear model (MLM) analysis with optimum compression with P3D method and kinship matrix. As a result, 312 significant MTAs were identified and a maximum number of MTAs (70) was identified for 100-seed weight. A total of 18 SNPs from 5 genes (ERECTA, 11 SNPs; ASR, 4 SNPs; DREB, 1 SNP; CAP2 promoter, 1 SNP and AMDH, 1SNP) were significantly associated with different traits. This study provides significant MTAs for drought and heat tolerance in chickpea that can be used, after validation, in molecular breeding for developing superior varieties with enhanced drought and heat tolerance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Chromosome Mapping
  • Cicer / genetics*
  • Cicer / growth & development
  • Droughts
  • Gene Frequency
  • Genome, Plant*
  • Genotype
  • Linkage Disequilibrium
  • Microsatellite Repeats
  • Phenotype
  • Plant Roots / genetics
  • Polymorphism, Single Nucleotide
  • Quantitative Trait Loci
  • Temperature

Grants and funding

This study was undertaken as a part of Tropical Legumes I (TLI- Objective 4: Chickpea) funded by Bill & Melinda Gates Foundation (BMGF) through CGIAR Generation Challenge Programme (http://www.generationcp.org/). This work has been undertaken as part of the CGIAR Research Program on Grain Legumes. ICRISAT is a member of CGIAR Consortium. DArT Pty. Ltd. provided support in the form of a salary for author AK, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of the authors are articulated in the "author contributions" section. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.