Leaf spot disease on lindens caused by the fungi Cercospora microsora Sacc. and Gloeosporium tiliae Oudem

Abstract

Certain of the growth characteristics of Cercospora microsora Sacc. and Gloeosporium tiliae Oudem. - causal agents of leaf spot diseases on lindens (Tilia cordata Mill.) in urban plantings in Slovakia were studied under laboratory conditions. Myceliar growth of C. microsora and G. tiliae was observed in pure hyphal cultures in relation to the medium and locality. In Cercospora study, one-way ANOVA has generally confirmed a statistically significant influence of both factors, medium and locality on growth rate of C. microsora, but in the case of the locality Nitra, the significant influence of the used media has not proved (p > 0.05). PDAg was generally shown as a medium inducing the most intensive growth in both localities (43.04 mm/4 days on average). Comparing the two localities, growth rate values from the locality Bratislava indicate unsuitability of water agar as a medium for the fast growth in culture. In Gloeosporium study, one-way ANOVA confirmed a significant influence of the factor medium as well as the locality on growth rate of G. tiliae. Influence of the used media was proven more markedly. Malt agar induced the most intensive growth in both localities (46.05 mm/4 days on average). Comparing the two localities, the samples from the locality Nitra showed in average the highest values of the growth rate. A Tukey test (ANOVA) separately conducted for the factors medium and the locality for both investigated fungal species, revealed the significant combinations of means (p ≤ 0.05).