Genetic variation and phylogenetic relationships of triazine-resistant andtriazine-susceptible biotypes of Solanum nigrum - analysis using RAPD markers

The expansion of weed species is a major problem in agriculture, especially when the number of herbicide-resistant biotypes is rising continuously. Th e major ecological questions associated with the evolution of herbicide res istance involve an intricate understanding of the interplay between gene fr equency, fitness, inheritance and gene flow. In this study, the RAPD (Rando m Amplified Polymorphic DNA) technique, which facilitates detection of vari ability at DNA level, was used to examine the spread of Solanum nigrum L. p opulations. Twenty-five populations, from Poland, France and the UK, were a nalysed. Six populations from Poland and one from France showed target site -based triazine resistance. The genetic relationship between individuals wa s studied using the RAPD technique. It was found that some resistant popula tions from the Gabin and Grojec areas show very high affinity levels compar ed with individuals from France. Three groups of populations in which resis tance had developed independently were distinguished. The results of the pr esent investigation suggest that migratory birds, such as Turdus pilaris L. and Sturnus vulgaris L., play an important in spreading S. nigrum seeds.