Exploring Potential of Pearl Millet Germplasm Association Panel for Association Mapping of Drought Tolerance Traits

Sehgal, D and Skot, L and Singh, R and Srivastava, R K and Das, S P and Taunk, J and Sharma, P C and Pal, R and Raj, B and Hash, C T and Yadav, R S (2015) Exploring Potential of Pearl Millet Germplasm Association Panel for Association Mapping of Drought Tolerance Traits. PLoS ONE. pp. 1-28. ISSN 1932-6203

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Abstract

A pearl millet inbred germplasm association panel (PMiGAP) comprising 250 inbred lines, representative of cultivated germplasm from Africa and Asia, elite improved open-pollinated cultivars, hybrid parental inbreds and inbred mapping population parents, was recently established. This study presents the first report of genetic diversity in PMiGAP and its exploitation for association mapping of drought tolerance traits. For diversity and genetic structure analysis, PMiGAP was genotyped with 37 SSR and CISP markers representing all seven linkage groups. For association analysis, it was phenotyped for yield and yield components and morpho-physiological traits under both well-watered and drought conditions, and genotyped with SNPs and InDels from seventeen genes underlying a major validated drought tolerance (DT) QTL. The average gene diversity in PMiGAP was 0.54. The STRUCTURE analysis revealed six subpopulations within PMiGAP. Significant associations were obtained for 22 SNPs and 3 InDels from 13 genes under different treatments. Seven SNPs associations from 5 genes were common under irrigated and one of the drought stress treatments. Most significantly, an important SNP in putative acetyl CoA carboxylase gene showed constitutive association with grain yield, grain harvest index and panicle yield under all treatments. An InDel in putative chlorophyll a/b binding protein gene was significantly associated with both stay-green and grain yield traits under drought stress. This can be used as a functional marker for selecting high yielding genotypes with ‘stay green’ phenotype under drought stress. The present study identified useful marker-trait associations of important agronomics traits under irrigated and drought stress conditions with genes underlying a major validated DT-QTL in pearl millet. Results suggest that PMiGAP is a useful panel for association mapping. Expression patterns of genes also shed light on some physiological mechanisms underlying pearl millet drought tolerance.

Item Type: Article
Divisions: RP-Dryland Cereals
CRP: CGIAR Research Program on Dryland Cereals
Uncontrolled Keywords: Pearl Millet; Germplasm; Panicles; Africa, Drought; Leaves; India; Serine; Variant genotypes; Chlorophyll; Drought tolerance
Subjects: Mandate crops > Millets > Pearl Millet
Depositing User: Mr Ramesh K
Date Deposited: 11 Aug 2015 05:51
Last Modified: 21 Oct 2016 04:45
URI: http://oar.icrisat.org/id/eprint/8924
Official URL: http://dx.doi.org/10.1371/journal.pone.0122165
Projects: UNSPECIFIED
Funders: BBSRC and DFID
Acknowledgement: The authors wish to acknowledge Biotechnology and Biological Sciences Research Council (BBSRC) and Department for International Development (DFID) for funding the work via grant. The authors wish to thank all support staff who contributed to the development of the PMiGAP, as well as to seed multiplication of the PMiGAP testcrosses and phenotyping of these testcrosses. The authors are also thankful to Mrs. Kirsten Skot for genotyping PMiGAP with SSRs and InDel markers at in-house facility at IBERS and P. Maheshwar Rao for phenotyping PMiGAP for leaf rolling and senescence.
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