Genetic Variability and Association of Characters in Ethiopian Basil (Ocimum basilicum L.) Germplasm

Background and Objective: Sweet basil (Ocimum basilicum L.) is an important herbaceous aromatic and medicinal plant that belongs to the Lamiaceae family. The extent of genetic diversity is not well investigated. Therefore, the objective of this study was to evaluate the genetic variability of sweet basil using quantitative morphological traits. Assessing variability is essential to identify the most important traits in sweet basil accessions which help in crop improvement programs. Materials and Methods: An experiment was carried out in a simple lattice design with forty-nine accessions of sweet basil in two replications. After three months, five plants per plot from the central rows were randomly selected and data was collected from a total of 10 plants for each accession from two replications. Estimation of variance components and association of characters analyzed for quantitative traits were performed using the R software. Results: High estimates of GCV and PCV were recorded for essential oil yield (58.87%; 78.25%), fresh leaf weight per plant (36.79%; 42.89%), petiole length (27.80%; 30.88%) and leaf length (25.81%; 27.67%). High heritability estimates were observed for leaf length (86%), length of inflorescence (84%), petiole length (81%), fresh leaf weight per plant (72%), plant height (70%) and leaf width (64%). High genetic advance over a mean (GAM%) recorded for essential oil yield (90.03%), fresh leaf weight per plant (65.01%), petiole length (51.57%), leaf length (49.61%), length of inflorescence (29.72%) and leaf width (27.36%). Estimation of genotypic correlation coefficient among traits indicated that there was a positive and highly significant correlation between fresh leaf weight per plant was significantly and positively correlated with leaf width (r = 1), leaf length (r = 0.99) and length of inflorescence (r = 0.77). Conclusion: Thus, the result indicated that higher values of heritability showed lesser environmental and greater genetic effects which can be used in future breeding programs.