Genetic variability of Linnaea borealis – remnant of Eastern-Southeastern Alpine populations indicates a strong bottleneck and in situ glacial survival

Abstract

In a rapidly changing environment, habitat loss and fragmentation have primarily led to a decline in the numbers of numerous plant species. We compared the genetic variability of two small, isolated populations of Linnaea borealis L. with three populations from the core distribution area in the boreal region. The results show three main clusters, exemplars from the boreal distribution area being represented in all three clusters. The genetic variability within the two isolated Eastern-Southeastern Alpine populations was found to be very low, while genetic variability between them was very high. In addition, a low proportion of different genotypes was revealed in the Eastern-Southeastern Alpine populations as compared to the northern population. The high genetic variability between the two isolated Eastern-Southeastern Alpine populations indicates that most likely both are glacial relict populations, probably due to consecutive bottlenecks and long-term isolation under specific environmental conditions. Glacial relicts, which tend to be associated with endangered habitats, deserve urgent attention, especially when the recent anthropogenically-driven environmental crisis is considered.