| | A high level of systemic fungal growth by Fusarium culmorum in winter wheat was demonstrated by isolation in a study from the Netherlands. Studies in Canada showed that F. graminearum isolates from roots and crowns of wheat can cause fusarium head blight. The current study was undertaken to evaluate the potential for systemic infection in barley by artificially inoculating the growth medium in pots containing seedlings of AC Lacombe barley. Furthermore, naturally infected wheat kernels were grown out to assess the potential for systemic infection of F. graminearum into the stem. Approximately 50% of naturally infected wheat seeds either failed to emerge or seedlings died shortly after emergence. Crown and stem discoloration was found from the inoculated barley and naturally infected wheat seed. Mycelial infection and sporulation were observed in the crown area using light and electron microscopy. Systemic infection evidenced by the presence of fungal hyphae was observed in the stem tissues above the crown up to 15-20 cm at approximately the 3rd internode. Fusarium graminearum was identified through isolation. Fungal hyphae were mostly located in the parenchyma tissue and culm, with few in the vascular tissue. In conclusion, no evidence was found for systemic infection leading to head blight of barley or wheat. Under growth chamber conditions seed and seedling infection by F. graminearum and subsequent systemic fungal growth can lead to infection of the lower stem. Research is needed to determine if similar results occur under field conditions.
K. Xi1 and T.K. Turkington2
1 Alberta Agriculture, Food & Rural Development, Field Crop Development Centre, c/o Lacombe Research Centre, 6000 C & E Trail, Lacombe, AB T4L 1W1
2 Agriculture & Agri-Food Canada, Lacombe Research Centre, 6000 C & E Trail, Lacombe, AB T4L 1W1
Presented at the 3rd Canadian Barley Symposium, June 19-20, 2003 |
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