Taxonomic novelty in Pleomonodictydaceae and new reports for Ampelomyces quisqualis (Phaeosphaeriaceae), Melomastia maolanensis and M. oleae (Pleurotremataceae)

Abstract

This study introduces a novel genus Robiniigena, with its type R. hyalinospora. The specimen was collected on dead aerial branches of Robinia pseudoacacia in Italy. Based on the examination of morphology and the results of phylogenetic analyses involving nuclear 18S rDNA (SSU), nuclear 28S rDNA (LSU), nuclear rDNA ITS1-5.8S-ITS2 (ITS), translation elongation factor 1-alpha (tef1-α) and RNA polymerase II second largest subunit (rpb2) sequences, Robiniigena is referred to the family Pleomonodictydaceae (Pleosporales). It is characterized by immersed to erumpent, ostiolate ascomata, filiform, septate and cellular pseudoparaphyses, bitunicate, clavate to cylindric-clavate asci and fusiform, hyaline ascospores surrounded by a mucilaginous sheath. This research also establishes the taxonomic placement of the previously unclassified Inflatispora (Pleosporales genus incertae sedis) within the Pleomonodictydaceae. The sexual morph of Ampelomyces quisqualis (Phaeosphaeriaceae) is described for the first time and it is characterized by immersed, perithecial ascomata, a peridium comprising two layers, branched, septate and filiform pseudoparaphyses, short-pedicellate, bitunicate asci with an ocular chamber and sub-hyaline, fusiform, septate ascospores. This species, previously known only in its asexual morph, has been found as a saprobe on Sonchus sp. in Italy. Our identification of the sexual morph was based on LSU rDNA and ITS rDNA sequence data. Melomastia maolanensis (Pleurotremataceae) is reported for the first time in Thailand, collected from Chromolaena odorata, while M. oleae is documented as a new record from Duranta erecta in Thailand.