Das Projekt "Adaptive genetic variation and plant adaptation to environmental heterogeneity (AVE)" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Institut für Agrarwissenschaften, Departement Biologie durchgeführt. The question how organisms become adapted to their environment is of central interest in biology. The present project investigates the genetic basis of adaptation to harsh and changing environmental conditions in alpin plant species using a population genomic approach. Sessile organisms, such as plants, have to be able to adapt to their environmental conditions, both biotic and abiotic, in order to survive. In some landscapes, and especially in the Alps, environmental conditions can change over small geographic scales. Here, sites with contrasting environmental conditions, brought about for example by differences in exposure, snow cover or bedrock, are often located in close physical proximity and within the reach of contemporary gene-flow. In the face of such environmental heterogeneity, natural variation is essential for the adaptation of plants to their environment. Natural selection acts on phenotypic variation, much of which presumably has a genetic basis in natural plant populations. Understanding the nature of the genetic variation underlying this phenotypic variation is of long-standing and general interest in biology. Most genetic variation in natural plant populations is presumably neutral, and difficult to distinguish from genetic variation underlying differences in adaptive traits. One approach to identify such adaptive genetic variation is to establish an association between specific environmental conditions and genetic variation using a landscape genetic approach. The present study therefore addresses the following main questions: 1. What is the genetic basis of adaptation to environmental heterogeneity ? 2. Do the same genes contribute to adaptation in related species ? 3. What is the adaptive value of candidate genes ? With respect to these questions we hypothesize that 1. major genes contribute substantially to adaptation 2. the same genes (or gene families) are involved in adaptation to the same enviornmental factor in different species 3. some of the identified candidate genes cause above-average fitness in their native environment, but below- average fitness in other environments (i.e. display genetic trade-offs). Results from this study will provide new insights into the genetic basis of adaptation and the nature of adaptive genetic variation. This knowledge not only contributes to our understanding of natural variation and adaptation per se, but helps us to predict the effects of climate change on alpine plants and provides a scientifically informed foundation for the conservation of alpine plant biodiversity.