Morphological and Molecular Analyses of Grain Traits in Aromatic Rice Landrace Accessions from Indo-Gangetic Plain Region of India

Abstract

Information on genetic variation in rice grain’s morphological traits is vital, affecting its yield and quality parameters. In present study, 92 accessions of aromatic rice landrace germplasm from the Indo-Gangetic plain region of India have assessed for grain morphometric traits as-well-as for genotypic mutation in exon 3 of grain size (GS3) gene. Significant variability was detected for the grain traits, namely rough rice length and breadth (RRL, RRB), rough rice length/breadth ratio (RRLB), 1000-grain weight (TGW), brown rice length and breadth (BRL, BRB), and brown rice length/breadth ratio (BRLB). The highest values of the phenotypic coefficient of variation and genotypic coefficient of variation were observed for TGW (40.56; 38.38%) and the lowest for BRB (14.96; 15.02%). For all the grain traits, high heritability (broad-sense) was observed, which ranged from 85.67 (BRLB) to 99.13% (BRB). Genetic advances ranged from 0.58 (BRB) to 9.13 (TGW). Principal component (PC) analysis revealed that first two PCs explained 86.04% of phenotypic variation. A positive association found between all the grain traits except grain breadth (RRB and BRB), which showed a negative correlation with the grain length-breadth ratio. The variation revealed for C/A single nucleotide polymorphism in GS3 gene. The superior accessions for grain traits, namely RRB (Jeera Sail/IC419047), TGW (Hansraj/IC0419006) and BRL (Kala Jira/IC0419052) identified. The genetically variable germplasm of aromatic rice with superior grain traits could be utilized for genetic enhancement of grain size in aromatic rices.