Unveiling phenotypic diversity among tomato ( Solanum lycopersicum L.) accessions: a comprehensive analysis of agronomic and physicochemical traits

The rising significance of tomato (Solanum lycopersicum L.) in human diet necessitates the continuous search for genotypes with favorable alleles for agronomic and nutritional properties from untapped genetic diversity. In this study, the phenotypic diversity of tomato accessions was assessed for agronomic and physico-chemical traits to identify accessions with potential horticultural traits that can be utilized in tomato improvement programs. A set of 23 accessions collected from the National Horticultural Research Institute (NIHORT), Ibadan, Nigeria, and two traditional varieties used as checks were evaluated in a 5 x 5 alpha-lattice design with three replicates at the Teaching and Research Farm of Ladoke Akintola University of Technology, Ogbomoso, Nigeria in the main cropping season of 2021. Data collected includes six physico-chemical parameters and 11 agronomic traits. Analysis of variance showed that accessions varied significantly (p < 0.001) for all of the traits measured. Wide variations were observed for some traits suggesting a considerable level of diversity among the accessions. Accession NHTO-0199, with the highest fruit weight, had a 59% yield advantage over the best traditional variety. The first two principal components accounted for 53% of the total variation among the tomato accessions. The patterns of variation were described by the phenological stages of flowering, fructifying, fruit maturation, plant height, fruit yield components, lycopene, and vitamin C content of the fruits. The cluster analysis delineated the accessions into three distinct clusters and hybridization between clusters may generate desired allelic combinations useful for developing unique variety. The following top five accessions: NHTO-0352, NHTO-0350, NHTO-0199, NHTO-0351, and NHTO-0346 had outstanding performances for fruit yield and physico-chemical traits based on Rank Summation Index. These superior accessions can be advanced for further improvement and may be used as sources of traits in crosses to develop new breeding lines.