Influence of temperature on morphology and physiology of different isolates of Ampelomyces quisqualis

Temperatures significantly influenced the growth rate of the colonies and the highest radial growth rate was measured at 20°C for all strains. Interestingly, original climate at which A. quisqualis was isolated did not influence an adaptation to the temperature. In fact, strains isolated in countries with a warm climate grew well at low temperature and vice versa. Observing the conidial germination phase, tube length and especially germination rate of A. quisqualis conidia increased greatly in the presence of powdery mildew conidia in different temperature. Temperature in the tested range had no influence on the germination rate, but seems to have an effect on tube length. These results suggest that different strains of A. quisqualis may react in a different way to temperature and this aspect should be considered in the selection of commercial strains, especially in a view of climate change