Assessment of genetic diversity in androgenic-based doubled haploid-derived improved restorer lines of indica rice

Hybrid rice has a considerable yield advantage over inbred lines, but the adoption rate in India is quite slow. In a three-line hybrid rice breeding programme, the development of fertility restorer lines that have enhanced grain quality is crucial. Employment of doubled haploid (DH) technology will accelerate the development of improved R lines in a short period of time, thus hastening the pace of hybrid rice breeding. This investigation was carried out for the evaluation of genetic diversity and assessment of population differentiation in 113 DHs derived from BC1F1s of IMP. IR 42266-29-3R and Nagina 22. A total of 46 SSR (Simple Sequence Repeat) markers resulted in an average of 2.00 alleles per locus. Polymorphism information content (PIC) value ranged from 0.31 to 0.37 with an average of 0.36. RM496, RM25520, RM483 and RM553 were found to be the best markers for the identification of genetic diversity. Structure analysis classified 113 DHs into four groups, which matched the Neighbour-Joining method using UPGMA cluster analysis. The AMOVA results demonstrated substantial genetic variations within subpopulation than among sub-population. The SSR marker-based molecular fingerprinting could serve as a sound basis in the identification of genetically distant as well as in the duplicate sorting of the morphologically close population in future breeding programmes.