Study on contamination of canola seeds in plants infected to blackleg and Sclerotinia stem rot diseases

Diseases of canola including stem white rot caused by Sclerotinia sclerotiorum and blackleg caused by Phoma lingam are considered as the most important diseases in Iran. Seed infections have their own importance and vary annually under different conditions. For this investigation، 26 canola fields located in three areas of Eastern (Kalaleh)، Central (Ali Abad)، and Western (Kord-Kouy) regions of Golestan Province were selected to study both diseases. At the cropping season، seed samples of every 10 plants demonstrating the diseases were collected separately and transferred to plant pathology laboratory. Seed weight and seed germination factors were measured for each samples even on non-infected samples. The colonies grown were studied employing fungal identification keys. The seed weight of samples infected to blackleg did not show considerable difference with the control samples whereas sclerotinia had decreased this factor totally. There were not sensible differences between treatments for seed germination. Fungi including Alternaria، Penicillium، Aspergillus، Rhizopus، and Sclerotinia were identified on seed samples in this experiments. The seeds of blackleg infected plants did not result in seed contamination and only one sample of Sclerotinia affected plants demonstrated the fungal colonies of the pathogen.