Phenotypic Variability and Correlation Analysis of Selected Traits in Tomato (Lycopersicon esculentum Mill.), Cucumber (Cucumis sativus L.), Sweet Pepper (Capsicum annuum L.), Melon (Cucumis melo L.) and Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai]

A number of genotypes of tomato, cucumber, sweet pepper, melon and watermelon from various local and foreign sources were evaluated for quantitative and qualitative traits such as fruit length, diameter, pericarp thickness, flesh thickness, rind thickness, number of locules, total soluble solids, degree of femaleness (female flowers), fruit straightness and fruit quality rating. The degree of variability and correlation between traits were analyzed using Shannon Weaver (SW) diversity index and correlation analysis. Based on the SW diversity index, narrow variability was noted: in all fruit traits of tomato, in the fruit length and diameter of cucumber, and fruit length of melon. On the other hand, wide variability was noted in fruit length, diameter and pericarp thickness of sweet pepper, degree of femaleness, fruit straightness and fruit quality rating (FQR) in cucumber, fruit diameter, flesh and rind thickness in melon and in all traits evaluated in watermelon. Strongly correlated traits were recorded between fruit weight and fruit length and diameter and between fruit diameter and locules in tomato. In other crops, strong positive correlation was noted in fruit straightness and fruit quality rating in cucumber and between fruit diameter and flesh thickness in melon. Strong, negative correlation was noted between fruit length and diameter in sweet pepper. The significance of the variability as measured by SW index and the correlation of traits in crop improvement of tomato, cucumber, sweet pepper, melon and watermelon was discussed.