Assessment of genetic variability and character association for yield and its component traits in indigenous accessions of sweet basil (Ocimum basilicum L.)

Sweet basil (Ocimum basilicum L.) is a globally important aromatic and medicinal herb widely cultivated for its essential oils, culinary uses, and therapeutic properties. The present study aimed to assess the extent of genetic variability and trait interrelationships among fifty diverse basil genotypes, including elite lines, released cultivars, and germplasm, at ICAR–DMAPR, Anand, during the kharif season of 2024-2025. Twenty-four agro-morphological traits related to growth, biomass, and yield were evaluated. Significant genetic variability was observed across genotypes, with high genotypic and phenotypic coefficients of variation for most traits, indicating substantial genetic diversity and a predominance of additive gene effects. High broad-sense heritability coupled with high genetic advance as a percentage of the mean further suggested the suitability of these traits for effective selection. Correlation analysis revealed strong positive associations between seed yield per plant and various traits, including the number of leaves, dry stem weight, swelling index, test weight, root length, and days to maturity. Path coefficient analysis demonstrated that dry stem weight exerted the highest direct effect on seed yield, followed by length of leaf blade, fresh root weight, and days to 100% flowering. These findings highlight key traits that contribute to seed yield and suggest their potential use as selection indices in breeding programs aimed at improving yield and enhancing the genetic quality of basil.