Abstract
Lesion fragments from a resistant and a susceptible wheat infected with Pyrenophora tritici-repentis were placed on water agar. Frequency of isolation from both wheats increased similarly with lesion age. The widths of hyphae at the point of emergence from fragments increased with lesion age in the susceptible cultivar only. Diameters of 24-h-old mycelial colonies in the agar around fragments decreased with lesion age in the resistant line only. This indicates a diminishing vigour of hyphae in this line, possibly resulting from the accumulation of an inhibitory factor. In further experiments, fragments of lesions and uninoculated leaves were incubated for 2 h in water or nutrient solutions before conidia were added and germtube lengths assessed 4 h later. Uninoculated leaves were stimulatory to germ-tube growth. Lesions prevented this stimulation, indicating the presence of a post-infection inhibitory factor.
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Loughman, R., Deverall, B.J. Experiments with excised lesions from wheat leaves infected by Pyrenophora tritici-repentis . Australasian Plant Pathology 18, 90–93 (1989). https://doi.org/10.1071/APP9890090
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DOI: https://doi.org/10.1071/APP9890090