Introduction The sunfl ower broomrape (Orobanche cumana Wallr.) has become one of the most important parasites of this oleaginous crop in Russia, Ukraine, Moldova, Romania, Turkey, Bulgaria, Yugoslavia and Spain, but it has been also reported in other countries [7, 4]. O. cumana is an important problem because of the large area sown with sunfl owers in infested zones. In the area infested with broomrape, there has been a progressive development of this parasite in sunfl ower crops and a rapid appearance of new and more virulent races [2]. DNA markers are considered to be the most effective means for measuring genetic diversity between individuals and between related species or populations because of their high frequency of polymorphism and being environmentally neutral [1]. Random amplifi ed polymorphic DNA (RAPD) markers have been successfully and largely utilized for taxonomic and systematic classifi cation as well as genetic diversity studies of plants [5, 3]. Thus, the aim of the present study was to identify the virulence races of Orobanche cumana in different geographical populations. Material and methods The seeds of O. cumana were collected from different regions of the Republic of Moldova, România and Ukraine. The infl orescences were dried for 60 days at temperatures ranging from 20 to 34°C, after which the seeds were separated with 300-mm sieves and were stored in darkness at 4°C. Broomrape seeds were planted in spots with sunfl ower genotype susceptible to this parasite. Broomrape tubercles were used for DNA extraction [6]. A total of 6 primers were analyzed (OPB-11, OPG-06, UBC-250, UBC-215, A2, A3). The relative molecular mass of the amplifi cation products was calculated using 100 bp molecular markers DNA Ladder (Fermentas). A dendrogram was constructed using the binary data of RAPD primers (UPGMA clustering). Results and discussions RAPD marker based diversity analysis was undertaken to evaluate genetic relationships among O. cumana collected from 12 different geographical areas. The presence and absence of the amplifi cation products were used to calculate genetic distances among the broomrape from different regions and to construct a dendrogram by an average linkage cluster analysis. The matrix of the genetic distances and the cluster analysis clearly separated the twelve samples into six clusters. The fi rst cluster (I) included O. cumana from Dondușeni, Soroca and Bălți, the second (II) – Chișinău and Sîngera; the third (III) – only Rezeni; the fourth (IV) – Taraclia, Izmail and Fundulea; the fi fth (V) – Cimișlia and ȘtefanVodă; the sixth (VI) - Ciadîr-Lunga. Differentials permitting identifi cation of different virulence groups of the parasite were used.  Conclusions The phylogenetic analysis using differential lines showed that the virulence of populations of broomrape is very different in the infested areas. Populations collected from Donduseni, Soroca and Bălți belong to the race F. Broomrape from Chișinãu, Sîngera and Rezeni could  be race F or more aggressive. In the Cimișlia, Ștefan-Vodã, Taraclia, Ciadîr-Lunga, Izmail (Ukraine) and Fundulea (România) may be attributed to race G or more aggressive. These types of investigations allow to elucidate the dynamics of gene pools, structure of plants’ population and their distribution, as well as their adaptation to the environment and centers of origin.