Characterization of 'QTL-hotspot' introgression lines reveals physiological mechanisms and candidate genes associated with drought adaptation in chickpea. (25th August 2022)

• Record Type: Journal Article
• Authors: Barmukh, Rutwik; Roorkiwal, Manish; Dixit, Girish P; Bajaj, Prasad; Kholova, Jana; Smith, Millicent R; Chitikineni, Annapurna; Bharadwaj, Chellapilla; Sreeman, Sheshshayee M; Rathore, Abhishek; Tripathi, Shailesh; Yasin, Mohammad; Vijayakumar, Adiveppa G; Rao Sagurthi, Someswar; Siddique, Kadambot H M; Varshney, Rajeev K
• Editors: Foyer, Christine
• Is Part Of: Journal of experimental botany. Volume 73:Number 22(2022)
• Page Start: 7255
• Page End: 7272
• Publication Date: 2022-08-25
• Subjects: Chickpea -- Cicer arietinum -- drought stress -- haplotypes -- introgression lines -- legume -- marker-assisted backcrossing -- transpiration efficiency -- whole-genome sequencing; Botany -- Periodicals; Botany, Experimental -- Periodicals; Plant physiology -- Periodicals; 580
• DOI: 10.1093/jxb/erac348
• Languages: English
• ISSNs: 0022-0957

Abstract

Abstract : Allelic variation in the ' QTL-hotspot ' region confers drought adaptation in chickpea by influencing seed weight, flowering time, early vigour, and transpiration efficiency under water deficit. Abstract: ' QTL-hotspot ' is a genomic region on linkage group 04 (CaLG04) in chickpea ( Cicer arietinum ) that harbours major-effect quantitative trait loci (QTLs) for multiple drought-adaptive traits, and it therefore represents a promising target for improving drought adaptation. To investigate the mechanisms underpinning the positive effects of ' QTL-hotspot ' on seed yield under drought, we introgressed this region from the ICC 4958 genotype into five elite chickpea cultivars. The resulting introgression lines (ILs) and their parents were evaluated in multi-location field trials and semi-controlled conditions. The results showed that the ' QTL-hotspot ' region improved seed yield under rainfed conditions by increasing seed weight, reducing the time to flowering, regulating traits related to canopy growth and early vigour, and enhancing transpiration efficiency. Whole-genome sequencing data analysis of the ILs and parents revealed four genes underlying the ' QTL-hotspot ' region associated with drought adaptation. We validated diagnostic KASP markers closely linked to these genes using the ILs and their parents for future deployment in chickpea breeding programs. The CaTIFY4b-H2 haplotype of a potential candidate gene CaTIFY4b was identified as the superior haplotype for 100-seed weight. The candidate genes and superior haplotypes identified in this study have the potential to serve as direct targets for genetic manipulation and selection for chickpea improvement.