GENETIC DISTANCE AMONG TOMATO CULTIVARS AS MEASURED BY RAPD MOLECULAR MARKERS

Genetic distance was calculated among 55 Lycopersicon esculentum genotypes, which included both processing and fresh market cultivars. The genotypes represented a wide range of commercially available germplasm, including open-pollinated cultivars and commercial hybrids. Forty four random 10-mer primers were used to detect polymorphism. From each of the random primers an average of five polymorphic bands were classified as to their presence or absence for each genotype. The genetic distance between all pairs of genotypes was calculated. A multidimensional scaling (MDS) plat indicated that the processing cultivars, UC82 derivatives and fresh market types generally formed separate clusters. Within groups, genetic distance corresponded to relationships based on available pedigree information. The results of this experiment indicate that RAPD molecular provide a high degree of resolution for estimating genetic relationships among processing tomato cultivars. Moreover, the results suggest that RAPDs can be used to organize germplasm resources of tomato breeding programs for purposes of fingerprinting and variety protection.