Physiological Characteristics and Pathogenicity of eight Neofabraea Isolates from Apples in Czechia

摘要

We obtained seven isolates of Neofabraea alba and one of N. perennans from apples in Czechia. All of the Neofabraea isolates showed variable growth on 2.0 % malt-extract agar (MEA) over a wide range of pHs, from 3.0 to 10.0, and pH 2.0 suppressed growth. The temperature optimum was observed at 18 and 20 degrees C; growth was suppressed at 30 degrees C. Five isolates exhibited optimal growth at 20 and three at 18 degrees C. Isolate growth was similarly low at 25 and 5 degrees C. The most favorable medium for the growth of the Neofabraea isolates was oatmeal agar (OA). On 2.0 % MEA, potato-dextrose agar (PDA) and OA isolates formed fungus colonies with a mostly regular margin and abundant aerial mycelium. Fungus-submerged mycelium formed on potato-carrot agar and 0.1 % MEA with a twig of apple tree with a few aerial hyphae in the middle of colonies. In general, cv. 'Rubin' was the most susceptible and cv. 'Sampion' the most resistant apple fruit to the Neofabraea isolates. Cv. 'Rubinola' was more susceptible than cv. 'Rubin' to Neofabraea infection on branches and the formation of cankers. These results are valuable to further mycological and pathological research on the fungus and disease, including the development of measures for disease management.