Colony diameters after 7 days at 25°C were as follows: CYA: 70-77 mm, MEA: 56-60 mm, YESA: 69-79 mm, OAT: 42-45 mm, CREA: 3-4 mm and CYA + 5% NaCl: no growth. On CYA at 10ºC conidia germinate, at 15ºC, 20ºC and 30ºC growth is evident with colony diameters of 9-17 mm, 59-71 mm and 56-86 mm, respectively. The species does not grow on CYA at 37ºC and 42ºC while at 33ºC the colony diameters varies from 0 to 22 mm, indicating that at this temperature the growth response varies among the isolates. At 25ºC in CYA, the species showed yellow mycelium, poor sporulation, abundant salmon to pink sclerotia production, and reverse pale yellow in color. Figure 3 shows the colonies of A. labruscus (CCT 7800) on different …show more content…
In total, 23 isolates of this new species were found on the surface of grape berries, V.itis labrusca, cv. Bordô grown in Rio Grande do Sul (Serra Gaúcha). The origins of representative A. labruscus isolates are shown in Table 2. This new species was not found in the other Brazilian regions. Table 3 shows the frequency of A. labruscus on the samples from different vineyards of Rio Grande do Sul and the range of contamination. Serra Gaúcha has a distinct climatic condition for vineyards, with an annual average temperature of 17ºC, rainfall of 1700 mm and relative humidity of 76%. While most of the world’s vineyards grow the European cultivars (V. vinifera) which produces fine wine, in Brazil due to the high humidity conditions, this species was affected by fungal disease and did not adapt to Brazilian conditions. ThusThus, the rustic North American cultivars of V. labrusca were introduced, which showed high disease resistance, and today 80% of Brazilian vineyards grow the cultivar V. labrusca, especially in the State of Rio Grande do …show more content…
labruscus was able to grow at temperatures of 15ºC to 33ºC, with no growth at 37ºC. Most members of A. section Nigri can grow at 37ºC and even higher19,20, including the closely species A. homomorphus and A. saccharolyticus. A. labruscus has never been found before in European vineyards and grape products 21 indicating that A. labruscus have an association with V. labrusca rather than Vitis vinifera. Data on the growth temperature of A. labruscus show that this species is adapted to colder temperatures, which may be due to its North American origin and therefore well-adapted to the Serra Gaúucha region which is colder than the other regions in Brazil. In addition, data to be published later will show that this species has not been found in V. labrusca cv. Bordô vineyards in the North Brazilian