Peter Klinkhamer

A developing embryo of Cynoglossum officinale

Scientific background:
After starting out on population dynamics of biennial plants, my research interest shifted towards evolutionary questions related to plant defence and plant reproductive systems. With various colleagues (but mostly with Tom de Jong) I worked on evolution of semelparity, age of first reproduction, attractiveness, selective abortion, sex allocation and diversity of secondary metabolites. All these projects have a simlar approach. The starting point is a theoretical framework. Modelling and studing the most relevant ecological processes allows us to use experimental data to test quantitative and qualitative predictions on evolution and optimization. The life history work resulted in a book that is due to appear in November 2005 (De Jong TJ and Klinkhamer PGL: Evolution of Plant Reproductive Strategies, Cambridge University Press).
Presently and in the (near) future one of my new projects will be on "key factors in evolution and the diversification of plant species". This project is carried out in cooperation with Klaas Vrieling. As a model system we will use hybrids of Senecio species that occur in contrasting habitats. By producing an F2 generation of these hybrids it is possible to generate maximum variation of relevant traits against an, on average, equal genetic background. The research approach is to test the fitness of these hybrids in different environments and to determine the most relevant ecological processes. After having produced a genetic map, fitness-related molecular markers will be detected using QTL-analysis. Similarly we will detect fitness-related metabolites by e.g. NMR-analysis of (groups of ) F2-plants with low and high fitness. Analogous to QTL-analysis we call this new approach Quantitative Compound Analysis (QTC). This will be done in co-operation with the metabolomics group of the IBL. The importance of the identified QTC's will further be studied in bioassays. Combining QTL- and QTC- analysis will show if the fitness-related molecular markers are likely to represent genes coding for the identified compounds. In a later stage the actual genes can be identified and sequenced in cooperation with the molecular groups of the IBL. The distribution of compounds (and genes) among Senecio species together with their phylogeny will make it possible to study the evolutionary history of the trait. We have chosen to start this project by focussing on a potentially ecologically and economically important trait: resistance against herbivores and soil-born pathogens. Whenever possible the results on resistance will be incorporated in our research on resistance in Chrysanthemums. In addition we will start a parallel project with a similar approach using hybrids between inbred lines of Arabidopsis thaliana from contrasting habitats. Although we started an ecological study in a small number of populations, the latter project basically has to be started yet but will have the advantage that it is easier to cooperate with the molecular groups of the IBL and, of course, much more molecular information is already available. Running projects I will still be involved in include: selective abortion, the effects of habitat fragmentation on multitrophic systems, and the interacting effects between small scale population structure and adaptive traits on plant fitness.