Genetic diversity in 14 tomato (<i>Lycopersicon esculentum</i> Mill.) varieties in Nigerian markets by RAPD-PCR technique

Abstract

A total of 226 tomato (Lycopersicon esculentum Mill.) fruits sold in markets within three states in Southwestern Nigeria were purchased and differentiated into 14 varietal groups based on morphological parameters. The genomic DNA from the young apical leaves of the seeded plants were extracted and analyzed by the randomly amplified polymorphic DNA-polymerase chain reaction (RAPDPCR) technique. Seventy-four (74) amplified products were scored with 62.2% of them revealing polymorphism. The OPB-18 primer recorded the highest polymorphism (83.3%) and OPU-14 the least (44.4%). The dendrogram revealed 3 clusters. The genotypic relationships between varieties within clusters ranged from 2 in clusters 1 and 3 to 10 in cluster 2. Cluster 2 revealed 4 subgroups with two pairs of varieties (var. c and i and l and m) showing 100% similarities. The local names, place of cultivation and phenotypic characters expressed by the varieties were not suitable for varietal differentiation since phenotypically different fruits showed genotypic relatedness. The impression that tomato varieties from a particular geographical zone are genetically similar was therefore nullified.

Key words: Tomato, randomly amplified polymorphic DNA, polymerase chain reaction, molecular, genetic diversity, Lycopersicum.