Current insights into palm fungi with emphasis on taxonomy and phylogeny

Abstract

Palms (Arecaceae) are emblems of tropical forests and host a vast array of fungi. The fungi associated with palms have been studied for over two centuries. However, taxonomic identification of some taxa, especially of the prominent genera Anthostomella, Linocarpon and Oxydothis, when based solely on macro- and micro-morphological characteristics is confused and needs better taxonomic resolution. The present study contributes to palm fungal taxonomy by incorporating molecular approaches for fungal identification based on new collections from China and Thailand. In total, 538 samples with 248 successfully obtained fungal isolates were derived from about 23 palm genera. Preliminary analyses showed that these taxa could be recognized as 170 species belonging to 115 genera, 66 families, and three genera incertae sedis. The fungi were mainly distributed in Dothideomycetes (c. 57.6%) and Sordariomycetes (c. 40.6%), with a few Lecanoromycetes (0.6%), Leotiomycetes (0.6%), and Orbiliomycetes (0.6%). In the present study on palm hosts in different ecosystems, it becomes obvious that the biodiversity and specificity of palm fungi is a reflection of habitats more than the hosts or geographical distributions. Based on morpho-phylogenetic evidence, 109 interesting taxa have been illustrated and described, including one new family Pseudocapsulosporaceae, seven new genera and 48 new species. The new genera are Javarisimilis and Thecatisporium (Astrosphaeriellaceae), Neomorosphaeria (Morosphaeriaceae), Pseudocapsulospora (Pseudocapsulosporaceae), Pseudoeutypa (Diatrypaceae), Pseudothailandiomyces (Tirisporellaceae), and Subanthostomella (Xylariales incertae sedis). New species are Anthostomella arecacearum, A. foliatella, A. mangrovei, A. pseudobirima, Brunneiapiospora phoenicis, Diaporthe trachycarpi, Dictyosporium licualae, Ernakulamia palmae, Exosporium licualae, Fasciatispora asexualis, Javarisimilis palmarum, Koorchaloma arecae, Lophodermium nypae, Morenoina rattanica, Nemania palmarum, Neobambusicola palmae, Neodeightonia nypae, Neoeriomycopsis sabal, Neoleptosporella palmae, Neomassaria livistonae, N. palmae, Neomorosphaeria mangrovei, Neosetophoma trachycarpi, Niesslia trachycarpi, Orbilia licualae, Oxydothis caryotae, Ox. foliata, Ox. palmae, Ox. pyriforme, Ox. sinensis, Parateichospora palmarum, Periconia arecacearum, Phaeosphaeria palmae, Phyllosticta arecacearum, P. foliacea, Protocreopsis palmarum, Pseudocapsulospora phoenicis, Ps. rhapidis, Pseudomicrothyrium palmae, Pseudothailandiomyces nypae, Serenomyces phoeniceus, Stanjehughesia elaeidis, Subanthostomella palmae, Tetraploa palmae, T. phoenicis, Thecatisporium palmae, Virgaria palmae, and Yunnanomyces mangrovei. New combinations are proposed for four species. New sequences and a reference specimen are provided for Appendispora frondicola, the type species of Appendispora, which supports the replacement of this genus in Monoblastiaceae. Reference specimens are also provided for Anthostomella nypae, Arecophila nypae, Melanographium citri, M. palmicola, M. selenioides, and Trichobotrys effusus. The new hyphomycete species, Fasciatispora asexualis, is the first asexual report for the genus Fasciatispora. Sexual morphs of the genera Neoeriomycopsis and Yunnanomyces are reported for the first time. Furthermore, Hyde and co-workers specializing in palm fungi, have developed an online database of palm fungi, which will be updated with new and interesting palm fungi.