Abstract
The paper presents results of a study which aim was preliminary screening of intrapopulation genetic variability in Lamium incisum Willd. This weed species is rarely distributed in Poland and lessening its count during the last years. As a plant inhabiting anthropogenic sites it is exposed to extreme conditions and disturbances caused mostly by the progressive intensification of agriculture. In order to investigate the genetic variability of the selected population markers of ISSR category were used. The analysis of chosen individuals with use of three ISSR primers revealed total of 49 loci, of which only 15 were polymorphic. Nei's gene diversity index (HE=0.099) and the mean number of alleles per locus (AE=1.160) indicated low genetic diversity within the examined population. The research presented in this paper allows for a better learning of the genetic variability of the investigated species and considers probable factors influencing its level.