Biology of the Gaeumannomyces graminis Arx & Olivier/Phialophora radicicola Cain Complex on Roots of the Gramineae

摘要: Biological characteristics of the varieties Gaeumannomyces graminis Arx & Olivier and Phialophora radicicola Cain are reviewed. They include: 1) pathogenicity to roots cereals; 2) growth on living stem tissues; 3) type fungal growth-cessation structure formed or in host. Together, these provide a simple means characterizing isolates standard methods for assessing them presented. The role pigmented cells tissues (growth-cessation structures) host penetration is questioned, since they seldom associated with progressive infection by G. P. radicicola. However, taxonomic aid, especially as now known form cellophane overlying agar. New evidence presented factors affecting conidiation fungi. Flooding colonies distilled water induced formation conidia var. tritici Walker, (British but not type) graminicola Deacon, whereas none corresponding unflooded agar plates. Conidia were usually much larger germinated readily when response flooding; many fungi therefore have 2 conidial types, distinct both morphology behaviour. Preliminary results suggest that biotin nitrogen also affect conidium