The incidence of Fusarium species recovered from inflorescences of wild grasses in southern Manitoba

Abstract

Wild grasses were collected in June, July, and August, in 1999 and 2000, from three southern Manitoba locations: the Cereal Research Centre Field Station at Glenlea, the Tolstoi Tall-Grass Prairie Preserve, and the Living Prairie Museum in Winnipeg. A total of 1766 plants representing 34 species were collected and examined for the presence of Fusarium spp. Spikelets of the inflorescences were surface sterilized, plated on potato dextrose agar amended with streptomycin, and the isolated Fusarium spp. identified. Fusarium graminearum was the predominant species found. This species was isolated from 8% of the grass inflorescences examined and accounted for 62% and 59% of all species isolated at Glenlea and Tolstoi, respectively. At the Living Prairie Museum, only F. sporotrichioides was found. Other Fusarium spp. isolated at low frequencies included F. equiseti, F. oxysporum, F. avenaceum, F. culmorum, and F. poae. A seasonal trend in recovery of species was observed. In June, only F. graminearum and F. sporotrichioides were isolated from early flowering grass species. In July, F. equiseti, F. oxysporum, and F. culmorum also were isolated, while in August all seven Fusarium spp. were found. Fusarium graminearum occurred on 11 of the 34 grass species examined, and 7 of these grasses are reported as hosts in Canada for the first time. These results indicate that wild grasses harbor several species of Fusarium, including F. graminearum, the predominant species causing fusarium head blight in cereal crops in Manitoba.