First report of an endophyte (Diaporthe phaseolorum var. sojae) from Kandelia candel

Mangrove endophytic fungus 1893 was isolated from Kandelia candel from an estuarine mangrove on the South China Sea Coast. Two new lactones 1893A and 1893B, together with other known compounds, have been isolated from its fermentation broth. To classify the endophyte correctly for further industrial application, a combination of morphological and molecular techniques was used to approach its identity. The endophyte was compared with similar species having trichogynes or trichogyne-like hyphae which apparently fused with antheridium-like hyphae, and perithecia initials developing from an ascogonial coil surrounded by enveloping hyphae in early developmental stages on pure culture. Further morphological characteristics on host and non-host were used for comparison with similar species when the endophyte was cultivated on leaves of Kandelia candel and Mangifera indica, respectively, which resulted in classifying the endophyte as a Phomopsis species. The ITS sequence of rDNA was used to infer its phylogenetic relationships with Phomopsis species that resembled the strain in morphology or ecology. Finally, the endophyte was identified as Diaporthe phaseolorum var. sojae based on morphological and molecular evidence. Our study is a first report of Diaporthe phaseolorum var. sojae isolated from mangrove Kandelia candel. Foundation item: The search was supported partly by the Guangzhou Natural Science Foundation (Grant No. 2007Z3-EO581), the Guangdong Provincial Natural Science Foundation (Grant No. 2007A0200300001-7), the Chinese High-Tech 863 Project (Grant No. 2006AA09Z422), and the National Natural Science Foundation of China (Grant No. 20572136). The first two authors have the same contribution.