Abstract
Weeds are alternative hosts of plant pathogens and when colonized may not exhibit disease symptoms. In 2008 and 2009, samples of weeds and plant debris were collected from 12 locations in eastern Croatia, and 300 Fusarium isolates colonizing them were identified. Strains were grouped and identified based on morphology and amplified fragment length polymorphism (AFLP) patterns. Portions of the beta-tubulin and translocation elongation factor 1-a genes were sequenced from representative strains of each group to confirm the identifications. Fourteen Fusarium species were identified with F.graminearum (20%), F.verticillioides (18%), F.oxysporum (16%), F.subglutinans (13%) and F.proliferatum (11%) all present as more than 10% of the population. Fusarium acuminatum, F.avenaceum, F.concolor, F.crookwellense (F.cerealis), F.equiseti, F.semitectum, F.solani, F.sporotrichioides and F.venenatum, were all present at frequencies < 8%. Our results indicate that economically important Fusarium spp. may be isolated from numerous alternative hosts during the off season and that weeds and plant debris can serve as a reservoir of genetically diverse inoculum.