Detection and Identification of Decay and Pathogenic Fungi from Tanoak and Quercus ssp. Directly from Wood
S. Bergemann1, K. Hayden1, L. Costello2, T. Swiecki3, and M. Garbelotto1
The disease progression by secondary plant pathogens may be interrelated with Phytophthora ramorum in tanoaks and Quercus spp., however the synergistic effects remains unknown. Since plant pathogens and other agents of decay cannot be distinguished with certainty in trees on the basis of morphological characters and decay characteristics, the goals of the present research are to identify the pathogenic and decay agents from colonization patterns in wood and plant material. In California, 12 genera of basidiomycetes were identified that are responsible for most of the oak tree failures reported in California including Armillaria, Ganoderma, Hericium, Inonotus, Laetiporus, Omphalotus, Oxyporus, Phellinus, Pleurotus, Schizophyllum, Stereum, and Trametes. The focus of our diagnostic approach is aimed at developing primers at the generic level using the 28S region of the nuclear ribosomal DNA. Each taxon-specific primer was designed to produce a DNA molecule of different length; therefore, multi-plex PCR diagnosis may be performed to identify generic-specific taxa from the size of the PCR-amplified fragment. Primers were tested on DNA extracts from pure fungal cultures, and then on DNA extracts from wood colonized by decay agents. The development of rapid, accurate molecular approaches is pivotal for the identification and will aid in future research in understanding disease development, identifying diseased trees, spread from disease centers, and the synergism between P. ramorum and wood decay organisms.
1Dept. of ESPM-ES, UCBerkeley, Berkeley, CA
2UC Cooeprative Extension, San Mateo County, Half Moon Bay, CA
3Phytosphere Research, 1027 Davis St., Vacaville CA 95687-5495
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