Studies on Genetic Variability and Correlation among the Different Traits in Solanum lycopersicum L.

Abstract

In present study the genetic diversity in some tomato genotypes were investigated in two years at North-west of Iran where due to its geographical situation is one of the most favourable regions for tomato cultivation. Twenty five tomato genotypes were evaluated for yield and important morphological traits during 2006-2007. Experiment was conducted in a 5 lattice square design with 3 replications in each one of years. Data on morphological traits were collected from central row on individual plants basis on mean values of five plants of each genotype selected at random. Analysis of variance on the studied traits revealed significant differences among genotypes for all the characters except for fruit yield, total soluble solids, titratable acidity and number of tillers. Genotype year interaction was only significant for some of the characters including number of fruit per plant, titratable acidity and for fruit yield. Mean data revealed high range for most of studied traits. Maximum and minimum variability were observed for number of fruit per plant and pH respectively. Hierarchical cluster analysis allowed the assessment of similarity and clarified some of the relationships among tomato genotypes. UPGMA produced a dendrogram with four clusters. The first cluster included 64% of studied tomato genotypes. Results from the PCA indicated that more than 91% of the variability observed can be explained by the first seven components. Based on PCA, PC1 can be considered as representatives of fruit size, while properties that show high correlation with PC2 are the ones related to plant characteristics.