Characterization of ‘QTL-hotspot’ introgression lines reveals physiological mechanisms and candidate genes associated with drought adaptation in chickpea

Autor: Rutwik Barmukh, Manish Roorkiwal, Girish P Dixit, Prasad Bajaj, Jana Kholova, Millicent R Smith, Annapurna Chitikineni, Chellapilla Bharadwaj, Sheshshayee M Sreeman, Abhishek Rathore, Shailesh Tripathi, Mohammad Yasin, Adiveppa G Vijayakumar, Someswar Rao Sagurthi, Kadambot H M Siddique, Rajeev K Varshney
Rok vydání: 2022
Předmět:
Zdroj: Journal of Experimental Botany. 73:7255-7272
ISSN: 1460-2431
0022-0957
Popis: ‘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.
Databáze: OpenAIRE
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