Trait-based Differentiation and Agro-Morphological Profiling in Germplasm Accessions of Rice (Oryza sativa L.)

Abstract

Agro-morphological characterization of a total of 2,879 rice germplasm accessions was conducted during 2023. This large-scale evaluation aimed to document phenotypic variability among accessions for Nineteen qualitative agro-morphological traits following standard descriptors, with emphasis on visually distinguishable and agronomically relevant characteristics. The analysis revealed categorical variation across all 19 traits, indicating broad phenotypic diversity within the germplasm pool. High variability was observed in traits such as early plant vigour, leaf blade colour, leaf pubescence, panicle exertion, flag leaf angle, threshability, and leaf senescence—traits closely associated with early-stage plant establishment, reproductive success, and ease of harvest. Moderate diversity was noted in coleoptile colour, basal leaf sheath colour, stigma colour, apiculus colour, kernel colour, and hull colour, which, while less conspicuous, remain relevant for taxonomic differentiation and potential marker development. The remaining traits exhibited relatively limited variation, suggesting a degree of uniformity in those phenotypic expressions across accessions. The comprehensive documentation of these agro-morphological traits contributes significantly to the understanding of phenotypic diversity in rice germplasm. Such traits can serve as diagnostic markers in germplasm management, varietal identification, and breeding program design. Moreover, the presence of highly variable and easily observable traits among the accessions offers valuable opportunities for trait-based selection and genetic enhancement aimed at improving rice productivity, adaptability, and grain quality in diverse agro-ecological contexts.