Infection patterns of endophytic fungi in different leafing stages of Quercus serrata

Abstract

To add the knowledge on the transmission and infection pattern of foliar endophytic fungi on Quercus serrata, we isolated the fungi from the different leafing stages and seasons at a naturally regenerated forest. At the first leafing season in April 2007, the leafing stage of Q. serrata was divided into 5 stages and the morphotype composition and isolation rate of endophytic fungi were examined in each stage. These data were also taken at the first, second and third leafing seasons each equivalent to April, June and August in 2008. In the first leafing season in 2007, 10 morphotypes were obtained. In 2008, 15, 11 and 13 morphotypes were isolated in the first, second and third leafing seasons, respectively. Among the obtained isolates, Discula sp. was the highest in the isolation rate and increased during the first leafing season. The isolation of Discula sp. showed lower rates at the second and third leafing seasons, while the isolation rate of Phomopsis sp. was higher than that of Discula sp. at these seasons. These results indicate that the infection of a dominant leaf endophyte, Discula sp. might occur via a spore during the first leafing season. The frequent occurrence of Phomopsis sp. may be affected by the decrease in the spore inoculum of Discula sp.