Genetic Variation, Biogeographical History, and Conservation ofAnthyllis montanaL. Ssp.jacquinii(Kern.) Hayek (Fabaceae) at Its Northern Distribution Limit

Abstract

Genetic patterns in Anthyllis montana ssp. jacquinii populations from the species’ central Balkan distribution toward its northern distribution limit in Austria were analyzed against the background of their evolution, biogeography, and conservation. Genetic structure and diversity were assessed by DNA sequencing (ITS, trnH/psbA) and amplified fragment length polymorphisms (AFLPs). Provisionally, seed mass data were added. Four homoplastic mutations were observed within the trnH/psbA intergenic spacer, while ITS sequences were identical across populations. Population differentiation, as assessed by AFLPs, was moderate (). Isolation by distance was absent within the peripheral and central regions. Genetic-structure analyses revealed two groups, separating the two northernmost Austrian populations from the remaining populations. Population sizes were not correlated with the overall rather low genetic-diversity values, but AFLP diversity was not further reduced in peripheral populations. Seed mass was similar across populations. The unexpected diversity level of the peripheral populations might be best explained by persistence of ancient genetic diversity and accumulation of new mutations. The main evolutionary process acting is probably genetic drift, as confirmed by AFLP outlier analysis. Biogeographical and conservation perspectives emphasize the importance of the peripheral Austrian populations representing an independent gene pool within A. montana ssp. jacquinii.