Variability and Character Association in F2 Segregating Population of Different Commercial Hybrids of Tomato ( Solanum lycopersicum L.)

Abstract

The F2 segregating generations of exotic tomato hybrids were studied to measure variability, character association and path coefficient analysis. Analysis of variance for each trait showed significant differences among the genotypes. Very little differences were observed between phenotypic coefficients of variation (PCV) and genotypic coefficients of variation (GCV) for the traits days to first flowering (pcv=9.21, gcv=7.82), fruit length (pcv=17.14, gcv=14.84) and fruit diameter (pcv=17.10, gcv=14.92). High heritability (>50%) was observed for all the yield contributing characters except flowers per cluster (47.83%). High heritability associated with high genetic advance was observed for fruit clusters per plant (105.11), fruits per plant (103.43), branches per plant (34.49), fruits per cluster (47.43), individual fruit weight (77.73) and fruit yield per plant (108.25). Selection for such traits might be effective for the fruit yield improvement of tomato. Significant positive genotypic and phenotypic correlation was observed between plant height at first flowering, flowers per plant, fruits per cluster, fruit clusters per plant, fruits per plant with fruit yield per plant. Fruits per plant showed the highest positive direct effect (1.096) on fruit yield per plant followed by individual fruits per plant (0.674). Direct selection may be executed considering these traits as the main selection criteria to reduce indirect effect of the other characters during the development of high yielding tomato variety. @ JASEM Tomato is one of the most important and popular winter vegetable in Bangladesh. Tomato is an introduced crop in Bangladesh and provides less genetic variability. It is estimated that the genomes of tomato cultivars contain <5% of the genetic variation of their wild relatives. Since the 20 th century, human beings have created a huge array of morphologically different cultivars and forms from the single species S. lycopersicum via plant breeding. Through domestication, research and breeding activities that were implemented by scientists and breeders worldwide, modern tomato varieties (mostly hybrids) have been developed with all shapes, colors and sizes (Bai and Lindhot, 2007). In Bangladesh most of the tomato varieties are of inbred type, those are low yielder. Average yield of tomato is very low (7.51 t/ha) in Bangladesh compared to other tropical countries (15.