Genetic Variability Assessment of Tomato Genotypes for Morphological Traits under Arid Condition of Quetta Balochistan

Abstract

The assessment of genetic variability of available tomato material is an efficient strategy for identifying elite breeding lines and developing improved varieties for local ecologies. This study aimed to evaluate ten tomato genotypes with diverse genetic backgrounds for nine morphological traits in a Randomized Complete Block Design (RCBD) with three replications. The mean squares from analysis of variance revealed appreciable variation for almost all morphological traits, except number of pickings. This indicated that studied tomato material exhibited considerable genetic variability, suggesting the potentiality of evaluated tomato genotypes for breeding and genetic improvement of tomato through cross-breeding. The mean value of genotypes showed wide range of variation for all measured traits, particularly for tomato fruit yield per plant. The correlation analysis indicated that all traits were positively and significantly interlinked with each other. However, tomato yield showed strongly positive association with plant height, number of fruits per cluster, fruit length and fruit girth, days to flowering and number of pickings which indicating that selection based on these traits would be reliable. Multivariate principal component analysis (PCA) accounted for 91.54% of total variation which is explained by first two principal components (PCs) with individual contribution of 74.05% and 17.49% respectively. Moreover, PCA facilitated in identifying the most divergence genotypes for selection and hybridization. Conclusively, two potential genotypes, namely O.E GSNOR-05 and Tom-VSF-05 performed superior for almost all studied traits as compared to local check variety i.e., Rio Grande, which is popularly grown for high productivity. Other important tomato genetic resources, including Tom-VSF-06 and Empty line might be useful in crossbreeding programs for varietal development or novel gene incorporation. Thus, this study would provide a benchmark for upcoming varietal development programs in Balochistan.