The objectives of this research were to analyze the effect of temperature and light on in vitro germination of Phakopsora euvitis urediniospores, as well as the viability of urediniospores stored under different temperatures. For determined the incubation period was evaluate the germination of urediniospores in water-agar 2%, for 2, 4, 6, 8, 10, 12 e 24 h. In order to evaluate the effect of temperature and light in germination, urediniospores in a suspension onto petri dishes were kept at 15, 20, 25 and 30 ºC for 24 h, in the dark and under continuous light. For the viability study, urediniospores were stored in Eppendorf tubes at temperatures of -20±2, 5±2, 23±2 and 33±2 ºC, in dark. Viability was assessed through the germination of urediniospores on agar-water. It was observed that germination increased continuously between 6 to 24 h of incubation. The cardinal temperatures (minimum, optimal and maximum) for urediniospore germination in vitro was 11,6; 21,0 e 30,6 ºC; e 13,1; 21,0 e 30,0 ºC; respectively, under continuous light and in dark. The spore viability was drastically decreased during the 60-day period of storage; and the best temperature for storage was 23±2 ºC.
grapevine rust; urediniospores; Vitis spp
