Identification of stable heat tolerance QTLs using inter-specific recombinant inbred line population derived from GPF 2 and ILWC 292.

Ashutosh Kushwah,Inderjit Singh,Chellapilla Bharadwaj,Shayla Bindra,B S Gill,Dharminder Bhatia,Mahendar Thudi,Suruchi Vij,Sarvjeet Singh,Rajeev K Varshney,Gurpreet Singh,Swarup Kumar Parida

doi:10.1371/journal.pone.0254957

Abstract

Heat stress during reproductive stages has been leading to significant yield losses in chickpea (Cicer arietinum L.). With an aim of identifying the genomic regions or QTLs responsible for heat tolerance, 187 F8 recombinant inbred lines (RILs) derived from the cross GPF 2 (heat tolerant) × ILWC 292 (heat sensitive) were evaluated under late-sown irrigated (January-May) and timely-sown irrigated environments (November-April) at Ludhiana and Faridkot in Punjab, India for 13 heat tolerance related traits. The pooled ANOVA for both locations for the traits namely days to germination (DG), days to flowering initiation (DFI), days to 50% flowering (DFF), days to 100% flowering (DHF), plant height (PH), pods per plant (NPP), biomass (BIO), grain yield (YLD), 100-seed weight (HSW), harvest index (HI), membrane permeability index (MPI), relative leaf water content (RLWC) and pollen viability (PV)) showed a highly significant difference in RILs. The phenotyping data coupled with the genetic map comprising of 1365 ddRAD-Seq based SNP markers were used for identifying the QTLs for heat tolerance. Composite interval mapping provided a total of 28 and 23 QTLs, respectively at Ludhiana and Faridkot locations. Of these, 13 consensus QTLs for DG, DFI, DFF, DHF, PH, YLD, and MPI have been identified at both locations. Four QTL clusters containing QTLs for multiple traits were identified on the same genomic region at both locations. Stable QTLs for days to flowering can be one of the major factors for providing heat tolerance as early flowering has an advantage of more seed setting due to a comparatively longer reproductive period. Identified QTLs can be used in genomics-assisted breeding to develop heat stress-tolerant high yielding chickpea cultivars.

Highlights

Chickpea (Cicer arietinum L.) or Garbanzo beans is a cool season food legume, originated from South-Eastern Turkey [1]
After evaluating the recombinant inbred lines (RILs) population under late-sown irrigated and timely-sown irrigated environments at two locations and generating ddRAD-Seq data, this study reports a genetic map for the above mentioned population and identification of QTLs associated with heat tolerance
This study illustrated the presence of significant differences in interspecific RIL population and its parents for yield and yield contributing traits and physiological traits in late-sown as compared to timely-sown condition

Summary

Introduction

Chickpea (Cicer arietinum L.) or Garbanzo beans is a cool season food legume, originated from South-Eastern Turkey [1]. It is the second most consumed grain legume after dry bean grown worldwide. Chickpea is a nutrient-rich legume crop that contains 17–31% protein and significant amount of essential amino acids, vitamins and minerals [3]. It is free from anti-nutritional factors thereby the consumer preference for this legume is increasing. There is a vital call for developing chickpea varieties that are heat resilient

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