9712308 Stewart Fungi in the ascomycete order Hypocreales are extremely diverse and range from species parasitic on plants and on other fungi as well as on humans, to saprotrophic forms that decompose organic matter in soils and litter. Hypocrealean fungi produce powerful mycotoxins, some of which have found pharmaceutical application like cyclosporin and ergonovone. Most are inhabitants of bark, wood, and herbaceous parts of angiosperms and are common in both temperate and tropical regions. About 80 genera and 1500 species are currently recognized in classifications of Hypocreales. In addition to their ascomycetous (spores in a sac, or ascus) or sexual manifestation, many hypocrealean fungi form conidia or asexual spore-forming structures, and may live many generations as asexually reproducing entities. Many of these have been given scientific names under the artificial order Moniliales, perhaps the most important being the genus Trichoderma, a source of severe pathogens. Prof. Elwin Stewart at Pennsylvania State University and Dr. Gary Samuels at the Beltsville USDA laboratories are cooperating to supervise several students who will conduct taxonomic monographic research on select groups of Hypocreales and Moniliales, to define species limits, assess reliable characters for identification, test mating barriers between closely related species, and reconstruct phylogenetic or genealogical relationships based on DNA sequences obtained for targeted genes. Two major goals of this PEET enterprise are to assess overall biodiversity in the hypocrealean and monilialean fungi of the world, especially in the tropics where new taxa can be expected, and to integrate the current classifications of the sexual (teleomorphic) and asexual (anamorphic) forms of the fungi into a general phylogenetic framework, based on a large data set of DNA sequences. Such work will complement ongoing studies supported by NSF on other ascomycetes like Clavicipitales toward the goal of a phylogenetic framework for all ascom ycetes. Training of four new graduate students and of postdoctoral associates is integrated with the research projects, and includes collaboration with specialists throughout the U.S. and in Japan. Select products from the research are to be available over Internet, taking advantage of the USDA's Web operations.
