Studies on Genetic Variability for Yield and Its Attributes in Tomato (Solanum lycopersicon L.)

Abstract

The present investigation was carried out at the Horticulture Research Farm, Faculty of Agricultural Sciences and Allied Industries, Rama University, Kanpur (U.P.), to evaluate 20 genotypes of tomato (Solanum lycopersicum L.) for the nature and magnitude of associations among different characters with fruit yield per plant (kg). The experiment was conducted using a Randomized Block Design (RBD) with three replications. The analysis of variance revealed that the mean sum of squares due to genotypes was highly significant for all the traits studied, indicating the presence of substantial genetic variability. All the genotypes exhibited considerable variation across the characters under observation. Among the genotypes, 'Kashi Aman' recorded the highest fruit yield per plot (53.17 kg) and per plant (6.12 kg), while the lowest fruit yield per plot (10.16 kg) and per plant (1.41 kg) was observed in 'Kashi Vishesh'. In genetic studies, the phenotypic and genotypic coefficients of variation (PCV and GCV) were highest for plant height (28.82% and 28.94%, respectively), indicating ample scope for improvement through selection. Genotypic and phenotypic correlation coefficients revealed that fruit yield per plant showed significant and positive associations with plant height (0.309* and 0.302*), days to 50% flowering (0.381* and 0.366*), number of flowers per cluster (0.342* and 0.336*), and fruit yield per plot (0.991** and 0.961**). Path coefficient analysis indicated that the maximum positive direct effect on fruit yield per plant was exerted by plant height (0.2743 & 0.0464), number of flowers per cluster (0.0533), number of fruits per plant (0.0382 & 0.0388), fruit weight (0.2021 g), acidity (0.2907 & 0.1146 mg/100g), ascorbic acid (0.3098 mg/100g), total soluble solids (0.2999 & 0.095 °Brix), lycopene content (0.0248 mg/100g), peroxidase activity (0.0019 & 0.0124), and fruit yield per plot (0.9878 & 0.9304) at genotypic and phenotypic levels, respectively. These findings suggest that plant height, number of flowers per cluster, and fruit yield per plot are key traits that may be used as selection criteria to improve tomato yield.