Invasive plant Lupinus polyphyllus demonstrates high level of molecular genetic variation within and between populations at East European Plain

Genetic polymorphism of alien species in their secondary ranges is an important evidence of invasive process course. In this paper, we studied a molecular genetic variation of Lupinus polyphyllus Lindl. at geographically extensive material from different parts of its secondary distribution range at East European Plain and a contribution of L. polyphyllus to natural vegetation there. Genetic variation was studied on nuclear ribosomal internal transcribed spacer sequences ITS1-2, chloroplast intergenic spacer rpl32-trnL sequences, and on inter-simple sequence repeat (ISSR) markers. ITS1-2 sequences were non-informative markers of intra-species variability for L. polyphyllus. In the phylogenetic tree on the base of chloroplast rpl32-trnL sequences no geographical trend was revealed among and within the three major clades and subclades but sufficient level of intra-population variability was detected. ISSR sequences of 38 individuals demonstrated statistically significant among-individual variation both within local populations and among local populations. The latter was the only significant factor of sample differentiation in the reduced ordination space at two spatial scales: among the local populations (ANOSIM test, R = 0.33, p < 0.01) as well as among the enlarged locations consisting of the neighboring populations (R = 0.26, p < 0.01). All investigated populations of L. polyphyllus at East European Plain invaded anthropogenically disturbed habitats, with present or former settlement activity. The revealed genetic variability of specimens at the lowest spatial scale may be a cue for a high invasion potential of L. polyphyllus in the studied part of the secondary range at ongoing climatic changes.