Prevalence of fungi and fusariotoxins on barley seed from western Canada, 1995 to 1997

Abstract

To determine the mycoflora of barley seed (Hordeum vulgare) grown in western Canada, 1494 grain samples were collected over three years and combined according to year and crop district. Two hundred randomly selected seeds per crop district were tested for the presence of fungal infection by surface disinfecting then plating onto potato dextrose agar. At least 70 species representing 40 fungal genera were identified. Levels of Alternaria alternata, Bipolaris sorokiniana, and Fusarium graminearum were highest in the eastern prairies, whereas Cladosporium species, Drechslera teres, and Stagonospora nodorum were highest in samples from the western prairies. In 1996 and 1997, composite samples were analyzed by mass spectrometry for the presence of eight fusariotoxins. Deoxynivalenol levels ≥0.05 ppm were found in samples from 7 of 10 Manitoba crop districts and I of 19 Saskatchewan crop districts in 1996, and from 8 of 11 Manitoba and 1 of 20 Saskatchewan crop districts in 1997. Detectable levels of 15-O-acetyl-4-deoxynivalenol were present in samples from two Manitoba crop districts in 1996 and four in 1997.

Keywords:

• Hordeum vulgare
• Bipolaris sorokiniana
• Drechslera teres
• Fusarium graminearum
• Stagonospora nodorum
• deoxynivalenol