QTL mapping for nine drought-responsive agronomic traits in bread wheat under irrigated and rain-fed environments

PLoS One. 2017 Aug 9;12(8):e0182857. doi: 10.1371/journal.pone.0182857. eCollection 2017.

Abstract

In bread wheat, QTL interval mapping was conducted for nine important drought responsive agronomic traits. For this purpose, a doubled haploid (DH) mapping population derived from Kukri/Excalibur was grown over three years at four separate locations in India, both under irrigated and rain-fed environments. Single locus analysis using composite interval mapping (CIM) allowed detection of 98 QTL, which included 66 QTL for nine individual agronomic traits and 32 QTL, which affected drought sensitivity index (DSI) for the same nine traits. Two-locus analysis allowed detection of 19 main effect QTL (M-QTL) for four traits (days to anthesis, days to maturity, grain filling duration and thousand grain weight) and 19 pairs of epistatic QTL (E-QTL) for two traits (days to anthesis and thousand grain weight). Eight QTL were common in single locus analysis and two locus analysis. These QTL (identified both in single- and two-locus analysis) were distributed on 20 different chromosomes (except 4D). Important genomic regions on chromosomes 5A and 7A were also identified (5A carried QTL for seven traits and 7A carried QTL for six traits). Marker-assisted recurrent selection (MARS) involving pyramiding of important QTL reported in the present study, together with important QTL reported earlier, may be used for improvement of drought tolerance in wheat. In future, more closely linked markers for the QTL reported here may be developed through fine mapping, and the candidate genes may be identified and used for developing a better understanding of the genetic basis of drought tolerance in wheat.

MeSH terms

  • Agricultural Irrigation
  • Chromosome Mapping
  • Droughts*
  • Environment*
  • India
  • Quantitative Trait Loci*
  • Rain
  • Stress, Physiological / genetics*
  • Triticum / genetics*

Grants and funding

PKG was also awarded a National Academy of Sciences India (NASI) Senior Scientist Platinum Jubilee Fellowship during the tenure of this research work and VG was awarded a Junior Research Fellowship under the same program, and was later awarded the position of Senior Research Fellowship/Research Associate position under a DBT project. VG also thanks the UGC, Government of India for awarding Dr. D. S. Kothari Post-Doctoral Fellowship. VJ was awarded with CSIR-Nehru Science Post-Doc Fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.