Fusarium Species Isolated from Common Weeds in Eggplant Fields and Symptomless Hosts of Fusarium oxysporum f. sp melongenae in Turkey

Thirteen species of weed plants were collected between May and September in 2010 and 2011 from eggplant fields representing 11 distinct locations covering a wide geographical area of Turkey. Weeds are potential hosts of many plant pathogens and may not exhibit disease symptoms when colonized. Fusarium spp. were isolated from five monocotyledonous species and eight dicotyledonous species. A total of 212 isolates recovered from weeds were assigned to eight Fusarium species on the basis of morphological characteristics. F.oxysporum was the most frequently isolated species (29.7%), followed by F.solani (19.8%), F.graminearum (13.7%), F.verticillioides (12.7%), F.equiseti (9.9%), F.avenacearum (8.0%), F.proliferatum (3.8%) and F.subglutinans (2.4%). The F.oxysporum isolates from different weed hosts were characterized by means of pathogenicity and vegetative compatibility grouping (VCG) tests. Among these, 29 isolates were found to be pathogenic to eggplant cv. Kemer and re-isolated as Fusarium oxysporum Schlecht. f. sp. melongenae (Fomg) as evidenced. These isolates from weed hosts were assigned to VCG 0320. This study is the first report of Fomg isolated from weeds in eggplant fields in Turkey. None of the weed species tested showed symptoms of wilting in pot experiments, and F.oxysporum was isolated with greater frequency from all inoculated weeds. The results of this study indicate that several weed plants may serve as alternative sources of inoculum for Fomg, during the growing season.