Original Research ARTICLE
Towards defining heterotic gene pools using SSR markers in pearl millet [Pennisetum glaucum (L.) R. Br.]
- 1International Crops Research Institute for the Semi-Arid Tropics, India
- 2Acharya N. G. Ranga Agricultural University, India
- 3Aberystwyth University, United Kingdom
Pearl millet is a climate resilient crop and one of the most widely grown millets worldwide. Heterotic hybrid development is one of the principal breeding objectives in pearl millet. In a maiden attempt to identify heterotic groups for grain yield, a total of 343 hybrid parental [maintainer (B-) and restorer (R-)] lines were genotyped with 88 polymorphic SSR markers. The SSRs generated a total of 532 alleles with a mean value of 6.05 alleles per locus, mean gene diversity of 0.55, and an average PIC of 0.50. Out of 532 alleles, 443 (83.27%) alleles were contributed by B- lines with a mean of 5.03 alleles per locus. R- lines contributed 476 alleles (89.47%) with a mean of 5.41, while 441 (82.89%) alleles were shared commonly between B- and R- lines. The gene diversity was higher among R- lines (0.55) compared to B- lines (0.49). The unweighted neighbor-joining tree based on simple matching dissimilarity matrix obtained from SSR data clearly differentiated B- lines into 10 sub-clusters (B1 through B10), and R- lines into 11 sub-clusters (R1 through R11). A total of 99 hybrids (generated by crossing representative 9 B- and 11 R- lines) along with checks were evaluated in the hybrid trial. The 20 parents were evaluated in the line trial. Both the trials were evaluated in three environments. Based on per se performance, high sca effects and standard heterosis, F1s generated from crosses between representatives of groups B10R5, B3R5, B3R6, B4UD, B5R11, B2R4, and B9R9 had high specific combining ability for grain yield compared to rest of the crosses. These groups may represent putative heterotic gene pools in pearl millet.
Keywords: pearl millet, B- (maintainer) lines, R- (restorer) lines, SSR (simple sequence repeat) markers, gene diversity, PIC (Polymorphic information content), Heterotic groups
Received: 30 Jun 2017;
Accepted: 26 Oct 2017.
Edited by:Prashant Vikram, International Maize and Wheat Improvement Center (Mexico), Mexico
Reviewed by:Elisabetta Frascaroli, Università di Bologna, Italy
Vikrant Singh, Punjab Agricultural University, India
Copyright: © 2017 Ramya, Ahamed, Yadav, Katiyar, Raj and Srivastava. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Rakesh Srivastava, International Crops Research Institute for the Semi-Arid Tropics, Room # 110, 305 Building, ICRISAT, Room # 110, 305 Building, ICRISAT, Patancheru, 502 324, Telangana, India, r.k.srivastava@CGIAR.ORG