Das Projekt "Evaluating the Use of Nuclear Techniques for the Colonization and Production of Natural Enemies of Agricultural Insect Pests" wird vom Umweltbundesamt gefördert und von Universität für Bodenkultur Wien, Institut für Forstentomologie, Forstpathologie und Forstschutz durchgeführt. In order to study the effects of parasitoid associated factors on lepidopteran larval hosts we used g-irradiation of sterilize females of the braconid parasitoid Glyptapanteles liparidis. Along with eggs, G. liparidis females inject a secrete of the calyx gland containing particles of a symbiotic virus, the polydnavirus (PDV) and venom into the host. These associated factors are known from other host-parasitoid systems to suppress the immune system of the host and cause alterations in its development. g-irradiation should sterilize the eggs inside the wasp's ovary, so that sterile eggs are oviposited together with PDV and venom and the influence of parasitoid larvae inside the host is excluded. We irradiated G. liparidis females with different doses, ranging from 2.4 to 10.5 krad, in a Co60 g-irradiator. L. dispar larvae were stung by such irradiated wasps as well as untreated wasps, and the development of hosts and parasitoid progeny was controlled by rearing and dissections of hosts. Also G. liparidis were reared under controlled conditions to measure the effect of irradiation on their longevity and oviposition. A sting by an irradiated wasp (= pseudoparasitization) caused prolonged development and supernumerary molts of L. dispar larvae, and lead to the production of heavier pupae. However, such pseudoparasitized hosts suffered from higher pupal mortality due to incomplete larval-pupal molts or incomplete hardening of pupal cuticle. Effects on the host immune system were studied indirectly using an additional infection with the entomopathogenic microsporidium Vairimorpha sp. Pseudoparasitized hosts died earlier from the microsporidiosis and showed infections of higher intensity. For G. liparidis adults the g-irradiation caused no marked reduction in lifespan, except at the highest dose of 10.5 krad, but irradiated females laid significantly fewer eggs. The treatment did not result in complete sterilisation; about 10 to 20 percent of parasitoid eggs did hatch and such G. liparidis were able to complete their development to adults. Further studies will investigate the incomplete sterilization of G. liparidis eggs by g-irradiation. We will test whether these synovigenic wasps can recover after a certain time after irradiation and produce fertile eggs again. Consequently, we aim to develop a protocol of dose and timing of g-irradiation to give the best results for using it as a tool in studying the effects of PDV and venom of G. liparidis.
Das Projekt "Die Dynamik der introgressiven Hybridisierung von natürlichen und angesiedelten polyploiden Pflanzen in landwirtschaftlich genutzten Flächen und Uferlandschaften: Eine Evaluierung von molekulargenetischen Werkzeugen an Weide (Salix sp.) (DYNAMO)" wird vom Umweltbundesamt gefördert und von Universität für Bodenkultur Wien, Department für Angewandte Pflanzenwissenschaften und Pflanzenbiotechnologie, Institut für Angewandte Genetik und Zellbiologie durchgeführt. The main objective of this research project is to use and further develop molecular tools to determine the genetic identity of polyploid and introgressed populations. The use of different complementary approaches on the same carefully sampled material will enable accurate a ppraisal of the usefulness of the different techniques in (i) genotyping polyploid individuals; (ii) revealing hybrid identity; and (iii) estimating the extent of introgression in natural populations, all of which are very important issues in conservation genetics. The molecular tools that will be included in this study are: 1) a selection of RAPDs and AFLPs (manual) (partner 01), 2) enzyme consensus primers (partner 01), 3) nuclear SSRs (partner 02), 4) cpDNA and mtDNA sequence analysis (partner 03), 5) cp SSRs (partner 04). In this project the Salix alba - Salix fragilis complex will be used first as a model to verify whether genetic analysis of the same samples with different techniques do indeed give consistent results concerning the extent of introgression. Full-sib progeny of controlled inter- and intraspecific crosses shall form the basis of molecular marker selections. Thereafter, carefully chosen populations, originating from particular stretches of European river margins, will be analysed (e.g. River Rhine, Rhône, Schelde, Po, Donau). The evaluation of the ability of these techniques in hybridization-related research will allow end-users such as breeders and foresters to apply this knowledge in their particular fields of interest. Opportunities for dissemination of results and exploitation by potential end-users will be maximized through close association with the Biotechnology for Biodiversity Platform (BBP).