Meta-analysis of QTLs for drought, heat, and salinity tolerance identifies high-confidence MQTLs and candidate genes in chickpea (Cicer arietinum L.).

Abstract

A meta-analysis of 712 quantitative trait loci (QTLs) associated with traits conferring tolerance to drought, heat, and salinity stress was conducted in chickpea. Of these, 588 QTLs were successfully projected onto a high-density consensus map saturated with 14,246 markers. The resulting meta-QTLs (MQTLs) (54) had an average confidence interval (CI) of 1.01 cM, which was 3.49 times narrower than the CI of the original QTLs (3.53 cM) used in the meta-analysis. Significant single-nucleotide polymorphisms (SNPs) or marker-trait associations identified in previous genome-wide association studies were found to coincide with 36 of these MQTLs. Eleven MQTLs were identified as breeder's MQTLs due to their significant contribution to phenotypic variance (>10%), modest CI (<0.5 cM), and the inclusion of more than 10 QTLs. Candidate gene mining within MQTL regions revealed 49 high-confidence candidate genes associated with various abiotic stresses. Additionally, synteny and ortho-MQTL analyses among chickpea and two other legume crops, pigeon pea and pea, identified 23 ortho-MQTL regions. The markers associated with MQTLs can be utilized for MQTL-assisted breeding and to enhance the prediction accuracy of genomic selection in chickpea.