EXPLORING GENETIC VARIABILITY THROUGH MORPHOLOGICAL AND MOLECULAR APPROACHES IN LOWLAND RICE (ORYZA SATIVA L.) OF BIHAR

Abstract

To evaluate the genetic diversity and phylogenetic affinities between 22 distinct rice (Oryza sativa L.) genotypes based morphological traits and SSR based molecular analysis, research work was conducted at Rice Breeding Section(for DUS trait evaluation) and Rice Molecular Lab (for SSR marker analysis), Faculty of Agriculture, Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur. Through DUS based characterization, important differences were found in characteristics like auricle pigmentation, basal sheath color, stigma color, culm attitude, and Attitude of flag. A few genotypes displayed anthocyanin pigment in their leaf collars and purple auricles, which suggests trait-specific diversity. The range of grain morphology was short to medium in length and narrow to wide in breadth, therefore highlighting the phenotypic variation among genotypes. SSR based assessment of genetic diversity using 15 SSR markers revealed overall genotypic variance ranging from 0. 00 to 0. 994, the polymorphism information content (PIC) values averaged about 0. 75, showing that the markers were quite informative. Shannon's Diversity Index (H = 3. 091), Simpson's Index (λ = 0. 9545), and evenness (E. 5 = 1. 0) stating considerable allelic richness and diversity. Principal Coordinate Analysis (PCoA) clarified 42. 8% of total variation and exposed different spatial clusters; UPGMA clustering grouped the genotypes into four main clusters at approximately 60% similarity, hence showing significant genetic variance. The coexistence of both frequent and rare alleles as well as varied degrees of genetic distance helps to highlight the significance of these genotypes for germplasm preservation and breeding techniques. Combining morphological and molecular data offers a solid foundation for parent selection in rice improvement initiatives targeting yield, stress resistance, and genetic improvement.