New species and records of Coryneum from China

Abstract

Following the abandonment of dual nomenclature and the implementation of single-name nomenclature for pleomorphic fungi, Coryneum was considered to have priority over Pseudovalsa and was recommended for use. Currently, Coryneum is the only genus in the family Coryneaceae (Diaporthales). However, DNA sequence data are lacking for most Coryneum species, and no detailed phylogenetic analyses of the genus are yet available. In the present study, fresh Coryneum samples were collected from chestnut (Castanea) and oak (Quercus) trees in China and morphologically compared with accepted Coryneum species. Based on morphological characteristics, they were identified as one known species, Coryneum castaneicola, and three novel species described here as C. gigasporum, C. sinense, and C. suttonii. Conidial dimensions and host association were considered major characters for species distinction. The previously unknown sexual morph of C. castaneicola is reported and described. A phylogenetic analysis of nuc rDNA internal transcribed spacer (ITS1-5.8S-ITS2 = ITS) and large subunit (28S) sequence data of a representative matrix of Diaporthales confirmed Coryneaceae to represent a monophyletic clade. A phylogenetic analysis of a combined sequence matrix containing the ITS-28S rDNA, the translation elongation factor 1-α (TEF1α), and the second largest subunit of the RNA polymerase II (RPB2) of the four Chinese and four additional European Coryneum species was performed, confirming the distinctness of these novel species.

Morphology and phylogeny reveal two novel Coryneum species from China

“…Sequences generated from the above primers of the different genomic regions (ITS, LSU, TEF1-α and RPB2 ) were analysed in comparison to known species, Stilbosporamacrosperma (CBS 115073) and Stegonsporiumpyriforme (CBS 120522) were used as the outgroup taxa (Jiang et al 2018). All sequences were aligned using MAFFT v. 6 (Katoh and Toh 2010) and edited manually using MEGA v. 6 (Tamura et al 2013).…”

“…The genus Coryneum Nees is currently the only accepted genus in Coryneaceae and it forms a distinct phylogenetic lineage in Diaporthales (Senanayake et al 2017, 2018, Voglmayr et al 2017, Fan et al 2018a, Jiang et al 2018, Senwanna et al 2018, Wijayawardene et al 2017, 2018). The genus Coryneum was introduced based on the asexual morph, with C.umbonatum Nees as the type species (Nees von Esenbeck 1816), and the sexual morph Pseudovalsa Ces.…”

“…Most Coryneum species were considered as phytopathogens, which were discovered from cankers and dieback of shoots and twigs (Wijayawardene et al 2016, Senanayake et al 2017, Jiang et al 2018). However, diseases are commonly mild and only rarely cause serious symptoms in the hosts.…”

“…Coryneum species are generally considered highly host-specific, and 28 species and a variety were accepted in this genus before this study (Sutton 1975, 1980, Wijayawardene et al 2016, Jiang et al 2018, Senwanna et al 2018). Coryneumterrophilum was the only species isolated from soil, and the others were reported from dead branches (Table 1).…”

Identification of six Cytospora species on Chinese chestnut in China

“…nomic concepts of families, genera and species in Diaporthales (Rossman et al 2007, Senanayake et al 2017, 2018, including species of Aurantiosacculus, Coryneum, Cryphonectria, Dendrostoma, Endothia, Gnomoniopsis, Neopseudomelanconis and Ophiognomonia (Gong et al 2017, Jiang et al 2018b, 2018c, 2019a, 2019b, Jiang and Tian 2019.…”