Cultural characteristics and pathogenicity of Pestalotiopsis funerea on Cupressus arizonica
The fungal pathogen Pestalotiopsis funerea principally attacks conifer species, causing necrosis on infected tissues, and sometimes death of plants. The main objectives of this study were to determine optimal in vitro growth conditions for Spanish isolates of P. funerea and to evaluate the virulence of these isolates on Cupressus arizonica under field and laboratory conditions, with the goal of verifying possible correlations between these variables. Eight isolates of P. funerea derived from C. sempervirens, C. arizonica and Quercus pyrenaica were used in the assays. In the growth rate experiment, five culture media (PDA, MEA, WA, PCA and TAKAY medium) and six temperatures (5, 10, 15, 20, 25 and 30°C) were evaluated. In the pathogenicity tests, two different experiments were carried out: (i) laboratory inoculations used 30-mm-long twigs of C. arizonica; (ii) in field inoculations, twigs of C. arizonica were inoculated with mycelia through wounds. Four months after inoculation, length of the twigs affected by necrosis were measured. The results suggested that Spanish P. funerea isolates had optimum growth at 25°C on TAKAY medium. The fungus caused substantial necroses on C. arizonica twigs after inoculation in both excised twigs and on adult C. arizonica trees. A positive relationship between inoculations carried out under laboratory and field conditions was found. No clear relationships were found between cultural characteristics and pathogenicity for P. funerea.
Document Type: Research Article
Publication date: 2008-08-01