MOLECULAR CHARACTERIZATION AND GENETIC RELATIONSHIPS AMONG SOME TOMATO GENOTYPES AS REVEALED BY ISSR AND SCoT MARKERS

Abstract

Two molecular marker systems, SCoT and ISSR were used for genetic diversity analysis of eight tomato (Lycopersicum esculentum L.) genotypes. The molecular markers revealed robust amplification profiles. Using seven selected SCoT primers 63 bands were generated, of which 38 (60.3%) were polymorphic. Six selected ISSR primers amplified 55 bands with 26 (47.3%) being polymorphic. (PIC), (EMR), (MI) and (Rp) of the primers were calculated for the two marker systems and all the parameters examined found to be higher in SCoT system. SCoT and ISSR revealed different genetic similarity among the eight tomato genotypes. SCoT and ISSR techniques characterized the studied genotypes by many unique markers throughout 12 unique markers, for every technique. Genotype Super Queen showed 10 pos-tive genotype specific markers; followed by genotype Hellfrucht showed six geno-type specific markers (five positives and one negative) indicating that these markers may be associated with a feature that has not yet been determined. Consequently, SCoT markers would be a better choice compared to ISSR markers in characterization of tomato genotypes. Also, it can be concluded that in future study of genetic diversity like here more than one marker systems should be used for higher genetic resolution of the genome.