MOLECULAR CHARACTERIZATION OF TOMATO (Solanum lycopersicum L.) VARIETIES USING SIMPLE SEQUENCE REPEATS (SSRs) MARKERS.

Abstract

Genetic diversity is a crucial factor in breeding crop plants.  Molecular characterization of tomato (Solanum lycopersicum L.)  varieties using Simple Sequence Repeats markers was conducted with a view to selecting the best among the varieties. Eleven accessions were sourced from Akure, Ikare and Ibadan, sown in germination trays, transplanted to the field and was laid out in Randomized Complete Block Design (RCBD).  Data  on  plant  height,  number  of  branches/plant,  days  to  first  flowering,  days  to  first  fruit  set,  number  of  fruits/plant, number  of locules/fruit,  number  of  flowers/plant  and  number  of  clusters/plant  as  well  as  pericarp  thickness,  fruit  weight,  average  fruit  weight  and  fruit  yield/plant  were collected  and  analyzed  using  SPSS  version 20. Analysis of variance revealed significant variation (P≤0.05) among varieties for all studied characters. Morphological relationships among varieties were observed using Cluster Analysis which classified genotypes into five divergent groups.  Thirteen polymorphic Expressed Sequence Tag-derived (EST) SSRs primers amplified 143 DNA fragments and detected 61 alleles. The number of alleles per locus ranged from 5 to 7 with a mean of 4.69 per primer. The Polymorphic Information Content (PIC) also ranged from 40% to 84%.  Considerable genetic diversity among studied varieties was observed at morphological and molecular levels indicating valuable tomato germplasms which could be used for further genetic studies.