Morpho-Molecular Diversity of Four Mutants of NERICA Rice Based on SSR Markers

Abstract

Genetic variation in a species is the principal resource for plant breeding program. However, it increasingly narrowed due to various reasons including adoption of modern varieties and climatic change. Genetic variability can be artificially created by using mutagens such as, temperature, chemicals and radiation. The mutant lines created by mutagens are needs to be characterized before using in the breeding program. The present study investigates genetic variation in four NERICA mutants (N₄/250/P-1(2), N4/350/P-4(5), N₄/250/P- 2(6)-26 and N10/350/P-5-4 in comparison to their parents, i.e., NERICA-4 and NERICA-10 and BRRIdhan28 using morphological and molecular markers. Three SSR (microsatellite) markers were used to detect the levels of polymorphism among the mutant lines. A total of 10 alleles were detected among seven rice genotypes. The average number of allele per locus was 3.333. The polymorphism information content values in this study varied from 0.501(RM215 and RM510) to 0.685 (RM351). The set of microsatellite markers, used in the present study, provided a positive assessment of the ability of SSR markers in producing unique DNA profiles and establishing discrete identity of rice genotypes. Mutant lines N₄/250/P-1(2), N₄/350/P-4(5), N₄/250/P-2(6)-26 and N₁₀/350/P-5-4 showed less genetic diversity among them and with mother plants and BRRIdhan28. There is no heterozygosity among the lines. NERICA-10, N₁₀/350/P-5-4 and NERICA-4 showed 42.86% genotypic similarity whereas it was 28.57% between BRRIdhan28 and N₄/250/P-1(2) N₄/350/P-4(5) and N₄/250/P-2(6)-26. N10/350/P-5-4 mutant line showed the higher similarity to drought tolerant NERICA-4 and NERICA-10.