EVALUATION OF GENETIC VARIABILITY, HERITABILITY, GENETIC ADVANCE ON GROWTH TRAITS OF TEN TOMATO (Solanum Lycopersicon Mill.) GENOTYPES IN NIGERIA

Abstract Tomato (Lycopersicon esculentum Mill.) is a favorite vegetable crop in Nigeria and around the world. The crop, is plagued with pests, diseases, lack of high-yielding varieties and post-harvest losses. Hence the need of this study to evaluate the genetic diversity, genetic variability, heritability, genetic advance on growth traits of ten varieties of tomato. The study was conducted at Babcock University, Ilishan-Remo and Institute of Agricultural Research and Training (IAR & T), Ibadan. Ten varieties of tomato were selected and planted in nursery for four weeks before transplanting to the field at a spacing of 50 cm x 50 cm (40,000 plants/ha). The experiment was laid out in a randomized complete block design (RCBD) with four replicates. At maturity, data were collected on agronomic and yield traits. Genetic diversity, Genetic variability, Heritability, Genetic advance were estimated on growth traits. Data obtained were subjected to analysis of variance using SAS 9.4, 2013 at P≤0.05, and the means were separated using Duncan’s Multiple Range Test. There were significant differences among the genotypes of tomatoes planted in all the characters studied at 1% level of probability in both locations. Roma Savannah produced significantly higher fruit diameter (36.31mm), length (47.97 mm) and weight (38.05 g). TROPIMECH had the highest plant height (0.84 m), number of leaves (38.67) and number of branches (11.83). Plant height and number of fruits were significantly negatively correlated both at phenotypic and genotypic levels (-0.47, -0.59). Plant height and fruit length were negatively correlated at genotypic level (-0.39) while plant height and fruit weight were negatively correlated at genotypic level (-0.60), suggesting that selection directed at plant height will not favour tomato fruit yield. Generally, broad sense heritability ranged from 63.58 to 97.45, suggesting that characters evaluated were also under additive gene control. Characters such as fruit length and number of leaves had high genotypic coefficient of variability, heritability and genetic advance which were reliable predictors of yield. It is therefore recommended that TROPIMECH and UC 82 B varieties be used as putative varieties to improve genetic diversity.