TY - PRO AU - Nicholson,P. AU - Doohan,F. AU - Dubin,H.J.|Gilchrist,L.|Reeves,J.|McNab,A. AU - Joyce,D. AU - Rezanoor,H.N. AU - Simpson,D. AU - Smith,P.H. AU - Turner,A. AU - Weston,G. ED - Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Mexico DF (Mexico) TI - Detection and quantification of individual fungal species in fusarium ear blight by PCR SN - 968-6923-94-2 U1 - 632.4 PY - 1997/// CY - Mexico, DF (Mexico) PB - CIMMYT KW - Blights KW - Breeding methods KW - AGROVOC KW - Disease control KW - Epidemiology KW - Fungi KW - Fusarium KW - Pathogens KW - Plant diseases KW - Triticum KW - Plant breeding KW - CIMMYT N2 - Until recently, no method was available to identify and quantify individual Fusarium species present within plant tissue. Specific DNA markers have been identified for the Fusarium species that are predominant components of the 'fusarium ear blight complex' (scab) of cereals. In the UK and continental Europe, two varieties of Microdochium nivale (var. majus and var. nivale),formerly F. nivale, are also involved in the ear blight disease complex. Assays based on the polymerase chain reaction (PCR) have been developed for detection of several of these fungi in DNA extracts from plant tissue. These assays have been refined to enable quantification of each species, allowing the relative contribution of each component to the disease of the plant to be estimated. The role of trichothecene mycotoxins in the pathogenicity of Fusarium species towards cereals is also being investigated. Attempts to disrupt the Tri5 gene of F. culmorum are described, along with the results of experiments using Tri5 disruptants of F. graminearum. Visual disease scoring and quantitative PCR are being used to investigate the effects of Tri5 gene disruption on the infection of seedlings and ears of wheat. Examples of the use of PCR techniques in epidemiological studies involving F. poae, F. culmorum, F. graminearum, F. avenaceum, and M. nivale varieties are also presented. Other work ongoing in the research program is summarized ER -