Within Apocynaceae, interactions with pollinators are highly structured both phylogenetically and biogeographically. Variation in transition rates between pollination systems suggest constraints on their evolution, whereas regional differences point to environmental effects such as filtering of certain pollinators from habitats. This is the most extensive analysis of its type so far attempted and gives important insights into the diversity and evolution of pollination systems in large clades.

Semi-natural grassland areas expanded worldwide several thousand years ago following an increase in anthropogenic activities. However, semi-natural grassland habitat areas have been declining in recent decades due to changes in landuse, which have caused a loss of grassland biodiversity. Reconstructing historical and recent demographic changes in semi-natural grassland species will help clarify the factors affecting their population decline. Here we quantified past and recent demographic histories of Melitaea ambigua (Lepidoptera; Nymphalidae), an endangered grassland butterfly species in Japan. We examined changes in demography over the past 10,000 years based on 1378 bp of mitochondrial COI gene. We then examined changes in its genetic diversity and structure during the last 30 years using nine microsatellite DNA markers. The effective population size of M. ambigua increased about 3000-6000 years ago. In contrast, the genetic diversity and effective population sizes of many populations significantly declined from the 1980s to 2010s, which is consistent with a recent decline in the species population size. Our data suggest that the M. ambigua demography can be traced to changes in area covered by semi-natural grasslands throughout the Holocene.

Recent global land-use changes have led to reductions in many herbaceous plant species in semi-natural grassland landscapes. Changes in management frequency and intensity are known to cause declines in plant populations. However, little is known about the impact of changes in the timing of management practices on the genetic diversity as well as the reproductive success of rare semi-natural grassland species. We determined the suitable management (mowing) timing for Vincetoxicum pycnostelma Kitag. (Apocynaceae; Asclepiadoideae), an endangered summer-and autumn-blooming semi-natural grassland herb. We examined 15 V. pycnostelma populations to assess the effects of mowing timing on the genetic diversity of each population using nine microsatellite markers and on pollination and reproductive success. Pollination success was not affected by flowering timing. Mowing during the mid-to late flowering and fruiting periods of V. pycnostelma (July-September) had a significant negative effect on the number of inflorescences and total fruits produced, whereas mowing before flowering and growing periods (April-May and November-March) had positive effects on the number of inflorescences and fruits, respectively. Furthermore, mowing during the mid-to late flowering and fruiting periods also caused a significant decrease in genetic diversity. Our results demonstrated that mowing events during the mid-to late flowering and fruiting periods caused significant declines in the genetic diversity and/or reproductive success of V. pycnostelma. By contrast, mowing before flowering periods significantly enhanced reproductive success. To conserve semi-natural grassland herb diversity, mowing should be avoided during seasons when the flowering and fruiting periods of many endangered species overlap.

Museum specimens include genetic information from when they were collected. This historical information, which is very difficult to ascertain from samples collected currently, could be a valuable material for use in conservation genetics. However, the genetic analysis of museum specimens is technically difficult because of DNA fragmentation and the deamination of cytosine to uracil. In recent years, various methods have been developed for the genetic analysis of museum specimens, such as data analysis techniques including next-generation sequencing. The development of approaches that extract historical genetic information from museum specimens is expected to provide a new perspective on conservation genetics. This review focuses on the availability of museum specimens as genetic resources for conservation genetics. Some case studies are introduced, and perspectives on the future utility of conservation genetic studies using museum specimens are discussed. Moreover, recommended genetic analysis methods and important points for the usage of museum specimens are presented. This review provides a strong case for increasing the usage of museum specimens in conservation genetics studies in the future.