Assessing genetic variability and trait associations in rice (Oryza sativa L.): a study on yield components and grain quality

Abstract

Abstract Globally, rice is a staple food, with a daily caloric intake of approximately 20%. The purpose of the present study was to identify the important morphological and quality parameters through genotypic and phenotypic association and path analysis in Oryza sativa L. The breeding material used in this experiment comprised 60 diverse genotypes obtained from the Department of Plant Breeding and Genetics, The Islamia University of Bahawalpur, Pakistan. The experiment was conducted using a Randomized Complete Block Design, with three replicates. Phenotypic data for the different morphological and quality traits were measured at maturity. The results of the analysis of variance showed that all parameters except a few showed significant differences among genotypes, indicating substantial genetic diversity. Correlation analysis revealed that most of the morphological and quality traits exhibited positive associations with each other, indicating that improvements in morphology and quality could be based on these positively associated traits. Path analysis showed that the amylose contents (AC), flag leaf length (FLL), grain length (GL), plant height (PH), number of grains per panicle (GP), grain width (GW), and panicle length (PL) exerted the most prominent positive direct effects yield, highlighting their importance as key selectin traits. In contrast traits traits such as thousand grain weight (TGW), flag leaf area (FLA), grain length into width ratio (L/W ratio), and number of total tillers per plant (TP) showed negative direct effect,Suggesting a complex relationship with yield. The results suggest that improving primarily morphological traits, particularly flag leaf length and width, and grain length, along with the key quality trait amylose contents, which are directly and indirectly linked with yield, could be effective and their selection will facilitate the development of high yield and high quality rice cultivars to meet future food demands.