Latitudinal trends in genetic diversity and distinctiveness of Quercus robur rear edge forest remnants call for new conservation priorities

作者：Camilla Avanzi, Francesca Bagnoli, Edoardo Romiti, Ilaria Spanu, Yoshiaki Tsuda, Elia Vajana, Giovanni G. Vendramin, Andrea Piotti · 发表于：bioRxiv (Cold Spring Harbor Laboratory) · 年份：2023 · DOI：10.1101/2023.10.30.564819 · 被引用次数：3 · 研究领域：Genetic diversity and population structure、Rangeland and Wildlife Management、Ecology and Vegetation Dynamics Studies

Abstract Knowledge of the spatial distribution of intraspecific genetic variation is essential for planning conservation actions, designing networks of protected areas, and informing possible assisted migration strategies. Although the Italian peninsula harbours unique genetic variation as a legacy of Quaternary migrations, only sporadic genetic information is available for forest tree species. Here, we present the first geographically comprehensive genetic characterisation of Quercus robur , an iconic broadleaved species of European floodplain forests, in an area which acted as a primary glacial refugium for the species. 745 individuals from 25 populations were sampled and genotyped with 16 microsatellite markers. Their genetic structure was assessed through various metrics of diversity and distinctiveness, as well as by Bayesian clustering and multivariate methods. The demographic history of inferred gene pools was evaluated through Approximate Bayesian Computation analysis. Genetic distinctiveness showed a decline with increasing latitude, while allelic richness reached its peak in central Italy. A south-to-north trend in the complexity of the genetic structure was observed, with peninsular Italy being characterised by intermingled gene pools in contrast to the relative homogeneity exhibited by northern populations. Demographic inference indicated that the southern gene pool has been genetically isolated since the penultimate interglacial, whereas populations from central ...