Genetic relationships between Sicilian wild populations of Brassica analysed with RAPD markers

Brassica comprises very variable species, both morphologically and genetica lly. Among these species. the Sicilian populations of Brassica sect. Brassi ca. species related to kale crops form a complex group. The genetic relatio nships among 15 populations occurring in Sicily and one from Calabria. repr esenting the existing diversity. have been investigated using random amplif ied polymorphic DNA (RAPD) markers. This assay, carried out with 22 arbitra ry primers generated 236 polymorphic fragments, 21 of which were specific f or single populations (mainly Brassica insularis. Brassica incana and Brass ica macrocarpa). Jaccard's genetic distances were computed and the phylogen ic tree was established using the UPGMA algorithm, The dendrogram obtained showed four branches grouping: (1) B. incana populations: (2) B. insularis and B, macrocarpa. occurring in small islands around Sicily: (3) B. rupestr is populations: and (4) B. villosa populations. Within B. rupestris, only B . rupestris subsp. brevisiliqua was clustered in the B. villosa group. The classification obtained is discussed with regard to the morphological, ecol ogical and geographical data.