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

Vijay Gahlaut,Harindra S Balyan,Gyanendra Singh,Pushpendra Kumar Gupta,Sindhu Sareen,Vandana Jaiswal,Bhudeva S Tyagi,Aimin Zhang

doi:10.1371/journal.pone.0182857

Vijay Gahlaut, Harindra S Balyan + Show 6 more

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https://doi.org/10.1371/journal.pone.0182857

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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.

Highlights

Descriptive statistics including values of mean, standard error (SE), range, coefficient of variation (CV %), ANOVA, estimates of heritability and violin plots showing distribution for all the nine agronomic traits in doubled haploid (DH) population in 22 environments are summarized in S3 & S4 Tables and Fig 1
Several QTL for different drought related agronomic traits were identified in IR and RF environments, these included only few major QTL
It was observed that specific genomic regions of chromosomes 5A and 7A were important for wheat improvement for drought tolerance through marker-assisted recurrent selection (MARS)

Summary

Introduction

In order to feed the growing human population with increasing per capita income and consumption, global wheat production need to increase by at least 50% by the year 2030 [2]. This target needs to be achieved despite reduced land area, reduced water for irrigation and the predicted climate change. It appears to be difficult in view of the fact that the rate of annual growth in wheat production has shown a decline from 3% to less. VJ was awarded with CSIRNehru Science Post-Doc Fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

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