Identification of some pathogenic fungal agents of crown and roots of rapeseed in Isfahan

The rapeseed (Brassica napus) is one of the most important oilseed crops throughout the world. This crop is being attacked by several pests and diseases. This studies were conducted for the identification of some fungal diseases under laboratory and glass-house conditions on rape plants in Isfahan areas including; Braan, Koohpayeh, Mahabad, Mobarakeh, Dehaghan, Kabootarabad and Fraydan, where the infected plants were collected from the infected fields. The studies indicated that there are certain fungal pathogens infecting the areal and underground of rape plants. Isolation and growing cultures for identification of Fusarium species were with consistent and proper preparation of cultures on SA, WA, PDA, SNA, CLA, NASH & NYDER. Obtained isolates were identified by using morphological and various keys. All isolates were categorized in 5 species of Fusarium including: F. culmorum,F. heterosporum, F. lateritium, F. oxysporum,F. solani and one species of Rhizoctonia (R. solani). Disease severity was calculated under laboratory condition and compared with control using scoring scales (0-24). Results showed that, the highest level of infection was recorded by F. culmorum, F. lateritium, F. oxysporum,F. solani and R. solani, whereas the least infection was noticed by F. lateritium and F. heterosporum. It was also tested the isolated species on growth of plant and symptoms of disease. On the base of analyzing the data using DMRT (P=0.01%, 0.05%) on shoot length, fresh and dry weight of plants by different isolated pathogen, it was noticed significant effect compared to control.