Endophyte composition and Cinchona alkaloid production abilities of Cinchona ledgeriana cultivated in Japan.

New eight endophytic filamentous fungi were isolated from the young stems of Cinchona ledgeriana (Rubiaceae) cultivated in Japan. They were classified into four genera based on phylogenetic analysis of the nucleotide sequences of the internal transcribed spacers (ITS1 and ITS2), including the 5.8S ribosomal DNA region. Of the eight fungi isolated, there were five genera Cladosporium, one Meira sp., one Diaporthe sp. and one Penicillium sp. Genus of Cladosporium and Meira were first isolated fungi from Cinchona plant. In a previous study, we applied the same process to the same plant cultivated in Indonesia. The endophyte compositions for the two cultivation regions were found to differ at the genera level. The ability of Cinchona endophytes cultivated in Japan to produce Cinchona alkaloids was also assessed. We found that three isolates have producing ability of Cinchona alkaloids. However, the amount produced was very small compared to that produced by the endophytes of Indonesian Cinchona ledgeriana. In addition, the total content amount of Cinchona alkaloids, especially quinine, produced by the extract of Cinchona cultivated in Japan was much smaller than that from Indonesia. These finding indicate that endophyte composition has an influence on the Cinchona alkaloid content amount in the Cinchona ledgeriana host.