Submitted to: Proceedings of Northeastern Weed Science Society
Publication Type: Abstract Only
Publication Acceptance Date: January 20, 1997
Publication Date: N/A
Technical Abstract: Regulatory agencies require some form(s) of identification of microbes proposed for release into the environment. We are developing molecular identification techniques in addition to morphological characters to identify and fingerprint fungal weed pathogens collected from outside the U. S. And tested for release as biological control agents against domestic weeds. We utilize different fingerprinting approaches for facultative and obligate pathogens, based upon the quantity and quality of extractable DNA from spores or mycelial cultures of the pathogen. Obligate rust pathogens collected for thistle control (Puccinia spp. for control of Carduus and Centuarea spp.) have yielded only enough DNA for procedures utilizing the polymerase chain reaction, so we have targeted amplified ribosomal RNA gene spacer regions for characterization of this group of organisms. Organisms which can be cultured and genetically manipulated, such as Fusarium oxysporum (f sp. erythroxylii for control of Erythroxylum coca), have been targeted for insertion of genetic markers. Myrothecium verrucaria, which is a potential broad-spectrum mycoherbicide when applied in suspension with invert emulsions, is being fingerprinted by a third approach, utilizing automated fluorescent Amplified Fragment Length Polymorphism (AFLP) analysis. The advantages and pitfalls unique to each technique will be discussed.