Aggressiveness of 42 isolates of Gibberella zeae (Fusarium graminearum) in wheat under field and greenhouse conditions

Head blight or scab is a destructive disease caused by Gibberrella zeae (Fusarium graminearum) in wheat-growing areas of the world. This study was conducted to determine the correlation between aggressiveness of 42 progeny of the G. zeae cross FG24 (Hungary) and FG3211 (Germany) in the greenhouse and across three field environments (location-year combinations). Methods of inoculation in the greenhouse and field were single-spikelet injection and spraying, respectively. Aggressiveness was measured as percentage infected spikelets in the greenhouse and head blight rating in the field (0-100 scale). Mean disease severity was similar in the greenhouse and field (34% and 30%, respectively). Significant (P = 0.01) genotypic variation in aggressiveness was found in both test systems with a high heritability (h(2) = 0.90). Correlation of aggressiveness between greenhouse and field was moderate (r = 0.66, P = 0.01), suggesting that aggressiveness was a genetically stable trait. Greenhouse aggressiveness could be a predictive measure of the disease severity caused by the same isolates in the field.