Data from: Evolutionary significance of the invasion of introduced populations into the native range of Meconopsis cambrica

The long history of the deliberate or accidental, human-mediated dispersal
of flowering plants has led to the introduction of foreign genotypes of
many species into areas of Europe hitherto occupied by potentially
distinct native populations. Studies of the genetic and evolutionary
consequences of such changes are handicapped by the difficulty of
identifying the surviving native populations of many species in the
absence of clear morphological differences. We investigated the
relationship between putative native and introduced populations of the
herbaceous perennial Meconopsis cambrica (Papaveraceae), as the isolated
native populations of this species can be identified by historical and
ecological evidence. In Britain the species is scarce and declining as a
native but has become increasingly frequent in recent decades as a garden
escape. Native populations from Spain and France were compared to native
and introduced British populations using ITS and cpDNA sequences and
AFLPs. Ten of the twelve British populations could be unambiguously
assigned to native or introduced groups using cpDNA and AFLPs. The
introduced plants appear to originate from the central and eastern
Pyrenees rather than from native British sites. Two populations (including
one previously considered native) cannot be classified unambiguously.
There is unequivocal evidence for unidirectional gene-flow from native
plants into two of the introduced populations and possible evidence for
hybridization in three other sites (two native). The absence of biological
barriers to hybridization suggests that the native and introduced gene
pools of M. cambrica in Britain might eventually merge.