OLALEYE, MONSURAT OLAJUMOKE2026-01-052026-01-052025-07-03https://ir.funaab.edu.ng/handle/123456789/479A Dissertation submitted to the Department of Plant Breeding and Seed Technology, College of Plant Science and Crop Production,Federal University of Agriculture,Abeokuta, in partial fulfillment of the requirements for the Degree of Master of Agriculture in Plant Breeding.ABSTRACT Tomato (Solanum lycopersicum L.) is a vital crop worldwide, valued for its economic and nutritional importance. Information on genetic contribution and inter-character relationship between fruit yield and agro-morphological traits of twenty accessions of tomatoes is needed for improvement of tomato, hence this study was conducted. The research was carried out at Teaching and Research Farm, Federal University of Agriculture, Abeokuta Ogun state (07° 20’N, 03° 23’°E) in April 2024 to July 2024 (early season) and July 2024 to November 2024 (late season). The experiment was laid out in a Randomized Complete Block Design (RCBD) in three replicates. Data were collected on number of days to emergence, number of days to flowering, number of days to maturity, number of fruits, stem girth (mm), peduncle length (cm), fruit length (cm), fruit width (cm) and fruit weight (g). Data were subjected to analysis of variance (ANOVA), significant means were separated using Duncan’s Multiple Range Test (DMRT) at 5% probability level, Genotypic and Phenotypic variance, Heritability (Broad sense), Principal Component Analysis (PCA), and genotypic, phenotypic and environmental coefficient correlation were evaluated. In early season, accessions were significantly different from one another for days to maturity and number of fruits at (P≤0.01). In late season, accessions were significantly different from one another for days to flowering and days to maturity (at P≤0.01). Mean separation showed that accessions NHTO 0347 and NHTO 0258 in early season and accessions NHTO 0254 and NHTO 0355 in late season had the highest fruit traits. For early season, the phenotypic coefficient variation ranged from 22.44 for days to emergence to 546.37 for fruit weight while genotypic coefficient variation ranged from 9.48 for days to emergence to137.94 for number of fruits. High heritability was recorded for days to emergence, days to flowering, days to maturity, peduncle length, and fruit length. For late season, phenotypic coefficient variation ranged from 7.90 for days to maturity to 194.46 for fruit length while genotypic coefficient variation ranged from 7.47 for days to emergence to 166.14 for fruit length. All traits had high heritability in late season. For the principal component analysis (PCA), the eigen values were greater than one in both seasons and cumulatively accounted for 72.98% and 64.22% of the total variation for early and late seasons, respectively. Fruit weight was the highest contributor in both seasons for first principal component. There were significant positive genotypic and phenotypic correlation between days to maturity and days to emergence, days to maturity and days to flowering, number of fruits and stem girth, fruit weight and fruit width. In conclusion, significant genetic variation exists among the tomato accessions evaluated for days to flowering, days to maturity and number of fruits. The positive significant correlation between two traits would facilitate selection and simultaneous improvement, particularly for economically important traits. Accessions NHTO 0347 and NHTO 0258 in early season and accessions NHTO 0254 and NHTO 0355 in late season could be used as parents in breeding programme.enThesis