Assessment of genetic variation among some introduced tomato (Solanum lycopersicum L.) varieties using SSR markers

Simple sequence repeats (SSR) is one of the most appropriate markers for variety identification as it has immense discrimination influence for varieties with restricted genetic variation. Total genomic DNA was extracted from young freshly leaves of five tomato varieties. Genetic characterization of introduced tomato varieties were investigated using 15 SSR markers. Out of the 15 markers, 14 gave polymorphic bands and therefore were considered for further analysis. The number of alleles ranged from 2.00 (SSR2), (SSR3) to 6.00 (SSR9), (SSR11) alleles per locus with a mean value of 4.07 alleles per locus. The average Polymorphic Information Content (PIC) value was 0.59 ranging from 0.31(SSR2) to 0.77 (SSR9). The most polymorphic primers were SSR9, SSR11, and SSR4 based on PIC values. The Agglomerative hierarchical clustering grouped the tomato varieties into two (A & B). At a coefficient of 0.88, cluster B had three sub-clusters BI (Heinz), BII (Shasta) and BIII (OP-B155 and CRI-P00). At a coefficient of 0.90 varieties OP-B155 and CRI-P00 were identified as the most genetically related varieties. The genetic distance information from this study might be useful for further implementation of breeding strategies.Key words: genetic variability, Solanum lycopersicum, simple sequence repeat, make