Alpine plants often appear to have long life-spans as an adaptation to harsh and unpredictable environmental conditions, yet many lack reliable indicators of age that would make it possible to determine their true longevity. Their extended life-spans also pose problems for measuring lifetime reproductive success, a key component of breeding system evolution in species such as the gynodioecious ...

Tests of selective neutrality based on comparative and population genetic data target different time scales of selection. Investigating both time scales on the same genes has rarely been done and yet can provide insights into histories of selection. In pathogens, such a comparison can elucidate whether the same genes experience recurrent positive selection across specialization events onto nove...

BACKGROUND Plant recruitment depends among other factors on environmental conditions and their variation at different spatial scales. Characterizing dispersal in contrasting environments may thus be necessary to understand natural intraspecific variation in the processes underlying recruitment. Silene ciliata and Armeria caespitosa are two representative species of cryophilic pastures above the...

The degree of sexual dimorphism in a trait may be determined directly by disruptive selection, as well as by correlations with other traits under selection. We grew seeds from nine populations of the dioecious plant Silene latifolia in a common-garden experiment to determine whether phenotypic variation and correlations existed for floral, leaf and resource allocation traits, and whether this v...

Cushion plants are important components of alpine and Arctic plant communities around the world. They fulfill important roles as facilitators, nurse plants and foundation species across trophic levels for vascular plants, arthropods and soil microorganisms, the importance of these functions increasing with the relative severity of the environment. Here we report results from one of the few expe...

We investigated the distribution of genetic variation within and between seven subpopulations in a riparian population of Silene tatarica in northern Finland by using amplified fragment length polymorphism (AFLP) markers. A Bayesian approach-based clustering program indicated that the marker data contained not only one panmictic population, but consisted of seven clusters, and that each origina...

Phytoecdysteroids from aerial parts of Silene guntensis B. Fedtsch were investigated and three phytoecdysteroids were isolated: 2,3-diacetate-22-benzoate-20-hydroxyecdysone (1), 2-deoxy-20-hydroxyecdysone (2), and 20-hydroxyecdysone (3). Their chemical structures were elucidated by DEPT, COSY, 1H and 13C NMR spectroscopy. The isolated compounds 1-3 and crude extracts were evaluated for their an...

There is an increasing recognition that individual-level spatial and temporal heterogeneity may play an important role in metapopulation dynamics and persistence. In particular, the patterns of contact within and between aggregates (e.g., demes) at different spatial and temporal scales may reveal important mechanisms governing metapopulation dynamics. Using 7 years of data on the interaction be...

Direct photolysis of 1-(o-(methoxymethyl)phenyl)-1-phenylsilacyclobutane yields three isomeric products attributed to intramolecular trapping of an initially formed silicon-carbon biradical intermediate by migration of the benzylic methoxy group to silicon, along with the (expected) intramolecularly ether-stabilized silene due to formal [2 + 2]-cycloreversion.