Diversity and genetic relationship in forty landraces of Cucurbita spp. collected at small farms in Rio de Janeiro, Brazil, were analyzed by RAPD and ISSR markers, using 20 and 15 primers, respectively. Both markers were efficient to cluster the accessions separating among species, but not so much to the detection of intra-specific variability, considering the event of different pairs of accessions comprising null genetic distances observed for both markers in C. moschata. Low values observed for genetic distance among the C. moschata landraces showed that most likely genetic losses is in progress in that region of cultivation due to anthropic and market pressure, which are stimulating the small farmers to abandon their local varieties in order to use commercial seeds, including hybrids, which is causing risk of genetic erosion.
genetic resources; germplasm characterization; genetic distance; molecular characterization; on farm conservation
