عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Several Fusarium species cause important diseases such as wilting and onion basal and scale rot all over the world lead to significant losses in the production. During the visits that were done from onion fields in Isfahan in the middle of the plant growth period, wilt symptoms were observed in the field as spots. Sampling of onions showing yellowish symptoms or leaf necrosis and wilting was done randomly. Also, during harvesting time of white onions in the fields and some onions in warehouse, symptoms such as watering and color changes were seen on several outer scales of onion in the neck area. A total of 60 Fusarium isolates were isolated from onion included; 35 isolates of Fusarium proliferatum, eight isolates of F. acuminatum, seven isolates of F. solani, four isolates of F. oxysporum, four isolates of F. falciforme and two isolates of F. sambucinum. Pathogenicitytest was carried out on external scales of onions at 25 ° C and 65% relative humidity and onion plant in greenhouse conditions. Two species of F. sambucinum and F. falciforme were isolated as causal agent of plant wilting from onions with root and crown color changes for the first time. In the present study, the symptoms of rot, discoloration and soft tissue formation on the scales around the white onions neck by Fusarium species are reported from Iran. Also, F. acuminatum was isolated from the onion as a causal agent of rot and color change of the scales for the first time.