Morphological and Molecular Characterization of Aromatic Rice (Oryza sativa L.)

Abstract

Rice is a major food crop belongs to poaceae family, grown worldwide to ensure the food security. The genetic variability among rice genotypes allows for the production of new varieties with desirable traits like disease resistance and increased tolerance to stress. In current study, we analyzed the genetic diversity among 20 aromatic rice genotypes based on morphological traits and molecular markers. Here, a number of morphological traits viz. Days to 50% flowering, Day to physiological maturity, plant height, number of reproductive tiller, flag and primary leaf related trait (length and width), grain yield per plant and test weight were analyzed and reported a significant genetic variability in morphological traits. Further, genetic polymorphism at molecular level using 14 SSR primers examined for characterization and differentiation of aromatic rice. Among 74 allelic variants including 14 unique alleles and 60 shared alleles were identified with an average of 5.285 alleles per primer using 14 primer pairs associated. The primer pairs such as, RM1240, RM3155, RM3333, RM3212, RM1209, RM8077 and RM6366 appeared to be highly polymorphic and comparatively more informative for the purpose of molecular profiling of aromatic rice genotypes. The polymorphism information content (PIC) values ranged from 0.568 to 0.804 with an average of 0.673. Phylogenetic analysis of aromatic rice carried out by using 14 SSR markers resulted into five clusters. Cluster I consist of three genotypes (Anandi dhan, Badshahbhog and Pusa Basmati-1612 ), cluster II with maximum of eight genotypes (Basmati CSR-30, Haryana Basmati-2, IR-64, Punjab Basmati-2, Punjab Basmati-3, Punjab Basmati-4, Pusa Basmati-1121 and Pusa Basmati-1609), cluster III with four genotypes (Kalanamak, Nagina Vallabh Basmati-1, Pant Basmati-1 and Pant Basmati-2), clusterIV with four genotypes (Vallabh Basmati-21, Pusa Basmati-1692, Pusa Sugandh-2 and Pusa Sugandh-3) and cluster V with minimum one genotype (Marcha Dhan). Pusa Basmati-1121 and Pusa Basmati-1609 genotypes are closely related with maximum similarity coefficients (0.88). The obtained knowledge could be utilized further in rice breeding programme for crop improvements.