Genetic diversity in Cirsium arvense (L.) Scop.

Abstract

Field populations of Canada thistle were mapped at two different sites using the Global Positioning system (DGPS). Thistles were distributed all over the fields, partly in patches. The genetic diversity of the Canada thistle field populations was estimated on the basis of 30 randomly taken sprouts per field on four fields at each site. Cluster analysis after scoring of 38 polymorphic band positions generated by REP-PCR revealed high values for genetic diversity, that is number of multilocus genotypes per field, and genetic distance deduced from allelic polymorphism. It is concluded that in contrast to the common view sexual reproduction may play an important role in the establishment and propagation of Canada thistle in the field.