LAUSR

Knowledge of the extent and structure of genetic diversity and a species’ ecological niche are integral to formulating management plans for the conservation of threatened species. This is particularly important for aquatic organisms, which are especially vulnerable to human-induced environmental degradation and experience rapid global decline. To develop a proper conservation strategy for a threatened aquatic plant, Ottelia acuminata (Hydrocharitaceae), we utilized species distribution modeling (SDM) to delimit its potentially suitable range, both under the current climate and the climate expected in the near future, and employed AFLP to analyze the extent and structure of genetic variation over its entire distribution range. The within-population genetic diversity (He = 0.085) was lower than in the other species of Hydrocharitaceae studied using AFLP. The structuring of the genetic variation corresponded well to the distribution of previously described phenotypic varieties. There was 100% clustering of individuals according to their population origin suggesting a lack of inter-population gene flow. Based on the results of SDM and population genetic analysis we recommend (i) collecting seeds from all extant populations for seed banking through cryopreservation and the creation of living collections; (ii) reintroductions after restoration of once-occupied habitats utilizing plants of local origin, or, if the local variety has been extirpated, utilizing the most genetically similar population representing the same phenotypic variety; and (iii) experimental introduction of the species into lakes, ponds and small rivers in protected areas within the identified suitable range utilizing either a single population or a mix of populations belonging to the same genetic or phenotypic group.