Cytological studies of early stages of powdery mildew in barley and wheat leaves: (II) significance of the primary germ tube of Erysiphe graminis on barley leaves☆

摘要: Early stages of the infection processes Erysiphe graminis hordei, race I (compatible with barley cv. Kobinkatagi) and tritici, t2 (incompatible were observed on (Hordeum vulgare L., by scanning electron microscopy. Behavior both fungi was similar nearly 99% germinated conidia races had more than one germ tube 12 h after inoculation. Among tubes, one, designated as primary tube, induced a host papilla or cytoplasmic aggregate below it 4 to 6 inoculation, another swelled become an appressorium. Almost every conidium which appressorium earlier tube. The results suggest that induction may be critical attempted penetration from same conidium. Micromanipulation indicated epidermal cell wall continuous attached firmly inner layer, also wax crystals leaves dissolved fungal structures penetrate, i.e.