The proper management of plant genetic resources, ex situ conservation in gene banks requires the selection of genetically distinct accessions for long-term preservation. The conservation of vegetable resources in the Latvian Gene Bank is prioritised particularly for the cultivars of local origin, old cultivars and landraces. Due to improper seed propagation the old cucumber cultivar 'Dindona Zalie Kekaru' was contaminated and became a population with a broad spectrum of phenotypic and genotypic diversity. Population dividing in different genotypes was started by inbreeding and family selection (sibline). This study aimed to detect genetic diversity between lines by using RAPD markers. In total 53 primers were tested for 17 inbred and siblines, derived from the population of 'Dindona Zalie Kekaru', and for one sample of a local cultivar 'Grivas'. We find polymorphism between lines for 26 primers, one primer was monomorphic, and with the other 26 primers there was no stated amplification. As expected, middle to high genetic diversity was established between the lines. Polymorphic loci varied from 50 to 100%.