干旱区生态环境知识资源中心

The prevalence of airborne Fusarium species was determined in the South East coast of Spain. Air-dust (down fall dust) was collected during September 2007, July, August and October 2008. Five different Fusarium species were isolated from the dust: Fusarium oxysporum, F. solani, F. equiseti, F. dimerum, and F. proliferatum. Pathogenicity assays were conducted with 17 of the collected isolates of Fusarium species: eigth isolates of F. solani, four of F. oxysporum, three of F. equiseti, and two isoaltes of F. proliferatum. Results show differences in the pathogenicity of the isolates tested. Little pathogenicity was observed on sorghum caused by F. oxysporum, F. proliferatum and F. equiseti, but three of the isolates of F. solani produced an extensive pre-emergence damping off on sorghum. On Brassica napus L., three isolates of F.solani, two isolate of F. equiseti and F. oxysporum and one isolate of F. proliferatum caused significant decrease in seedling emergence. Almost all plants showed root rot when they were inoculated with different species of Fusarium, althought fresh weights did not bring any information about the pathogenicity. The evidence of long distance aerial dispersal of pathogenic strains of Fusarium species has to be taken into account as survival strategy for plant pathogens within the population dynamics as well as for plant protection strategies. Fusarium spores dispersed by wind from infected crops to new cultivated areas may overcome effective ressistance.