ON THE MOLECULAR AND PHENOTYPIC CHARACTERIZATION OF AN ASSOCIATION MAPPING PANEL OF FINGER MILLET (Eleusine coracana L. Gaertn) GERMPLASM FOR DROUGHT ADAPTIVE TRAITS
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Date
2022-07-13
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University of Agricultural Sciences, Bangalore
Abstract
Finger millet is nutritive crop and grows well in resource limited environments. However, though a hardy species, finger millet is quite sensitive to drought and heat. Improving specific traits is known to impart lasting tolerance to abiotic stresses like drought. Previousresearch suggests that WUE, water mining and acquired tolerance have great relevance fordrought stress. We screened a panel of 350 diverse finger millet germplasm accessions including wild varieties and landraces for important drought adaptive traits in two seasonsPlants were grown in specialised Root-study structures. Significant genetic variability was noticed in these traits across seasons, indicating a strong genetic control. The panel wasalso investigated for acquired tolerance adopting the temperature induction response (TIR) technique. Specific contrasts for root traits and acquired tolerant traits, drought
susceptibility index (DSI) have been identified. The trait donor lines, GE 832, GE 4962 and GE 4596 can be used for future crop improvement programs.Introgression of complex physiological traits requires the help of molecular markers and
hence an elaborate GWAS analysis was performed using more than 15 million SNPs obtained from the whole genome re-sequencing of the entire panel. These SNPs were separately identified on the A and B sub-genomes of the cultivated tetraploid finger millet. Additionally, we identified 43 polymorphic SSR markers from five largest super-scaffolds of the draft genome of finger millet. The genetic diversity and population structure analysis detected a total of 671 alleles which ranged from 3 to 33 alleles per locus with PIC values varying between 0.39 and 0.94.The GWAS analysis detected 259 significant marker-trait associations. Also, association mapping by SSR markers through linkage disequilibrium discovered 67 significant marker trait associations. This analysis is the first of its kind in tetraploid species.