Occurrence ofFusariumSpecies in Scabby Wheat from Minnesota and their Pathogenicity to Wheat

Abstract

Fifteen Fusarium species were identified in 23,726 isolates obtained from scabby spring wheats [Triticum aestivum L.]. The wheat was collected in 1984, 1985, and 1986 from farm fields and agricultural experiment stations in 24 Minnesota countries located in the wheat growing areas of the state. Fusarium graminearum comprised 75% of the isolates, F. poae 17%, and the other species (F. equiseti, F. sporotrichioides, F. acuminatum, F. oxysporum, F. semitectum, F. moniliforme, F. avenaceum, F. subglutinans, F. proliferatum, F. sambucinum, F. tricinctum, and F. crookwellense) 1 to 2%. Most of the F. graminearum isolates produced perithecia in culture. F. graminearum and F. culmorum infected spikelets of Era wheat in glasshouse tests and spread from the inoculated spikelets into more than half of the spikelets in the spikes. Infection by the other 11 Fusarium species tested was confined to inoculated spikelets.