Conidia of Verticillium albo-atrum Reinke and Berthold, collected from shake cultures grown in Czapek broth, were sonified for 4 or 8 minutes or ground frozen in a mortar to obtain cell-free homogenates. These were assayed for certain enzymes associated with respiratory pathways. Malic dehydrogenase was the most active, glucose-6-P and NADH dehydrogenase were less active, NADH-cytochrome c redu...

Conidia were germinated at three temperatures in media in which available water, expressed as water activity, was controlled at three levels. Rate of germination in the basal medium (0.9964 water activity) was most rapid at 25 C and was inhibited at 15 and 30 C. Lowering the water activity at a particular temperature decreased rates of germination. However, at a low water activity (0.9778) germ...

The influence of Pratylenchus penetrans on the incidence and severity of Verticillium wilt was examined in the potato cultivars 'Kennebec', 'Katahdin', and 'Abnaki'. Single-stem plants were grown in soil maintained at a temperature of 22 +/- 1 C. Axenically cultured nematodes were suspended in water and introduced to the soil, at a rate of ca 5,000/25.4-cm pot, through holes made around each st...

Indirect evidence suggests that vascular coatings formed by plants in response to stress consist of suberin-like substances containing lipid and phenolic compounds. To provide more direct chemical evidence that coatings are suberin, we used a natural pathogen, Verticillium albo-atrum, or a stress-responsive hormone, abscisic acid, to induce coating in two isolines of tomato (Lycopersicon escule...