Morpho-phylogenetic evidence reveals novel species and new records of Nigrograna (Nigrogranaceae) associated with medicinal plants in Southwestern China

Abstract

During a survey of saprobic fungal niches in Southwestern China, eighteen ascomycetous collections of Nigrograna (Nigrogranaceae, Pleosporales, Dothideomycetes) were found on dead branches of medicinal plants. These taxa were characterized and identified based on morphological and culture characteristics, and phylogenetic analyses of a combined the internal transcribed spacer region of rDNA (ITS), nuclear large subunit rDNA (28S, LSU), RNA polymerase second-largest subunit (rpb2), nuclear small subunit rDNA (18S, SSU), and translation elongation factor 1-alpha (tef1-α) sequence dataset also confirmed their placement. As a result, four novel species, namely Nigrograna camelliae, N. guttulata, N. longiorostiolata and N. neriicola were described. Additionally, four new host records of N. acericola, N. magnoliae, N. oleae and N. thymi were introduced. Furthermore, this study addresses the taxonomic status of N. trachycarpi, proposing its synonymy under N. oleae. Detailed illustrations, descriptions and informative notes for each newly identified taxon and novel host record are provided in this study.