The female advantage in natural populations of gynodioecious Plantago coronopus: seed quantity vs. offspring quality.

In gynodioecious plant species, females can only persist when they have a reproductive advantage in comparison with hermaphrodites. However, several studies have shown that females do not necessarily produce more seeds than hermaphrodites, since seed production can be affected by population characteristics, such as female frequency or population size. The aim of this study was to quantify the female advantage across a large number of natural populations, examine its relationship with population sex ratio and size, and to assess the role of competition on the magnitude of the female advantage.

The impact of hybridization on long-term persistence of polyploid Dactylorhiza species.

Premise Of The Study: Hybridization may pose severe threats to the long-term survival of the parental taxa through introgression and the formation of hybrid swarms. However, when the resulting hybrids show strong male and female sterility, backcrossing and introgression are unlikely to occur, but the parental species may suffer from reduced male and female fitness.

Methods: We assessed the impact of hybridization on the long-term persistence of two food-deceptive orchids in the genus Dactylorhiza (the common Dactylorhiza maculata and the rare D.

Recent range expansion of a terrestrial orchid corresponds with climate-driven variation in its population dynamics.

The population dynamics and distribution limits of plant species are predicted to change as the climate changes. However, it remains unclear to what extent climate variables affect population dynamics, which vital rates are most sensitive to climate change, and whether the same vital rates drive population dynamics in different populations. In this study, we used long-term demographic data from two populations of the terrestrial orchid Himantoglossum hircinum growing at the northern edge of their geographic range to quantify the influence of climate change on demographic vital rates.

The effect of phenological variation in sex expression on female reproductive success in Saxifraga granulata.

Premise Of The Study: Differences in timing of flowering within and among protandrous plants shift the floral sex ratio from male to female dominance during the flowering season. Hence, the number of seeds produced by a single flower depends on traits of the flower itself (e.g.

Genetic Diversity and Spatial Genetic Structure of the Grassland Perennial Saxifraga granulata along Two River Systems.

Due to changes in land use, the natural habitats of an increasing number of plant species have become more and more fragmented. In landscapes that consist of patches of suitable habitat, the frequency and extent of long-distance seed dispersal can be expected to be an important factor determining local genetic diversity and regional population structure of the remaining populations. In plant species that are restricted to riparian habitats, rivers can be expected to have a strong impact on the dynamics and spatial genetic structure of populations as they may enable long-distance seed dispersal and thus maintain gene flow between fragmented populations.

Microsatellite primers for the gynodioecious grassland perennial Saxifraga granulata (Saxifragaceae).

Premise Of The Study: Nine polymorphic and 12 monomorphic microsatellite loci (simple sequence repeats [SSRs]) were isolated and characterized for the gynodioecious grassland perennial Saxifraga granulata. •

Methods And Results: Based on genomic screening of leaf material of four individuals from four populations, a total of 21 microsatellite primer pairs were designed for S. granulata.