LAUSR

Culture-based studies have recovered fungal endophytes from numerous plant hosts, while direct examination of sporulating cultures has enabled identification. However, many endophytes cannot be identified due to the fact that they only form mycelia sterilia in culture. Although next generation sequencing (NGS), as well as ITS sequence analyses have been used to identify endophytes, identification is still rudimentary. In this study, we isolated fungal endophytes from Rhizophora apiculata in Thailand and established how many can be identified to species level based on ITS sequence data. Endophytic fungi were isolated from leaves, petioles and aerial roots of R. apiculata in four provinces of Thailand. One hundred and fifty four isolates were obtained and initially grouped into 20 morphotypes based on cultural characteristics. Nine were sporulating morphotypes, which were assigned to seven genera (Colletotrichum, Diaporthe, Hypoxylon, Neopestalotiopsis, Neodevriesia, Pestalotiopsis and Phyllosticta), and eleven morphotypes were non-sporulating mycelia sterilia. Sequence similarity comparison and phylogenetic analysis of the ITS regions were further used to identify taxa. While ITS sequence data is reliable to assign isolates at the generic rank, and can be useful to identify taxa to species level in a small number of fungal genera, it cannot generally be used to determine specific species in most genera. ITS analysis classified 30 representative isolates into 20 taxonomic units residing in 15 known genera: Allophoma sp., Colletotrichum spp., Diaporthe spp., Hortaea werneckii, Hypoxylon griseobrunneum, Hypoxylon sp., Pestalotiopsis sp., Phanerochaete sp., Phyllosticta spp., Pseudopithomyces maydicus, Preussia sp., Nemania sp., Neodevriesia sp., Neopestalotiopsis sp., Mycosphere 8(10): 1869–1892 (2017) www.mycosphere.org ISSN 2077 7019