Taxonomic Reappraisal of Periconiaceae with the Description of Three New Periconia Species from China

Abstract

As a result of an ongoing research survey of microfungi in Yunnan, China, several saprobic ascomycetes were collected from various host substrates. Preliminary morphological analyses identified a few of these taxa as Periconia species. We obtained DNA sequence data of the Periconia species from pure cultures and investigated their phylogenetic affinities. Phylogenetic analyses of a combined LSU, ITS, SSU and tef1-α sequence dataset demonstrated that five isolates of Periconia formed well-resolved subclades within Periconiaceae. Accordingly, three new Periconia species are introduced viz. P. artemisiae, P. chimonanthi and P. thysanolaenae, and new host and geographical records of P. byssoides and P. pseudobyssoides, are also reported from dead branches of Prunus armeniaca and Scrophularia ningpoensis. Periconia celtidis formed a monophyletic clade with P. byssoides in the present phylogenetic analyses. Results of the pairwise homoplasy index (PHI) test indicated significant recombination between P. byssoides and P. celtidis. Therefore, P. celtidis has been synonymized under P. byssoides. In addition, we re-illustrated and studied the type specimen of the sexual genus Bambusistroma. As a type species of Bambusistroma, B. didymosporum features similar morphology to the sexual morph of Periconia homothallica and P. pseudodigitata. We therefore synonymize Bambusistroma under Periconia based on morphological and phylogenetic evidence. Furthermore, our new isolates produced brown conidia of asexual morph in agar media typical of the genus Noosia. Based on morphological comparison with Periconia in vitro and phylogenetic status of Noosia, we also treat Noosia as a synonym of Periconia. Detailed descriptions and illustrations of three novel taxa and two new records of Periconia byssoides and P. pseudobyssoides as well as the illustration of P. didymosporum comb. nov. are provided. An updated phylogenetic tree of Periconiaceae using maximum likelihood and Bayesian inference analyses is constructed. Generic circumscription of Periconia is amended.

Morphology and phylogeny of ascomycetes associated with walnut trees (Juglans regia) in Sichuan province, China

“…Note: Our collections were morphologically similar to P. byssoides in having macronematous, mononematous, unbranched, erect, and light brown to dark brown conidiophores, monoblastic, ovoid to globose conidiogenous cells, and globose to subglobose, light brown to dark brown, verruculose, aseptate conidia (Jayasiri et al, 2019), which is also supported by phylogenetic trees (Supplementary Figure 7). Consistent with the conclusion made by Yang et al (2022), the morphological comparison of P. byssoides strains isolated from different hosts showed a slight variation in the size of conidiophores and conidia. Compared with previous reports, the conidiophores of our collections are especially shorter and wider (Markovskaja and Kačergius, 2014;Jayasiri et al, 2019;Tennakoon et al, 2021;Yang et al, 2022).…”

“…Consistent with the conclusion made by Yang et al (2022), the morphological comparison of P. byssoides strains isolated from different hosts showed a slight variation in the size of conidiophores and conidia. Compared with previous reports, the conidiophores of our collections are especially shorter and wider (Markovskaja and Kačergius, 2014;Jayasiri et al, 2019;Tennakoon et al, 2021;Yang et al, 2022). In this article, three isolates of P. byssoides are obtained from leaves and twigs of J. regia, and it is reported as a pathogen on J. regia in Sichuan, China for the first time.…”

“…In the present study, we described 10 species in Dothideomycetes and Sordariomycetes associated walnut trees. Within the broader region of China, there are reports of partial fungi on other known or undescribed plants ( Zhang, 2003 ; Zhu et al, 2016 ; Jayawardena et al, 2018 ; Long et al, 2021 ; Farr and Rossman, 2022 ; Wanasinghe et al, 2022 ; Xu et al, 2022 ; Yang et al, 2022 ). To our knowledge, these are the first accounts of these species in Sichuan province.…”

“…C. tenuissimum is a quite common saprobic species isolated from numerous substrates, and is the agent of leaf spot or blight disease in China ( Han et al, 2019 ; Li et al, 2021 ; Xie et al, 2022 ; Zhou et al, 2022 ). However, the isolates of P. byssoides , which have been verified based on molecular data, are saprobic on host plants in Vitaceae, Apiaceae, Cornaceae, Cannabaceae, Euphorbiaceae, Magnoliaceae, Fabaceae, and Rosaceae ( Yang et al, 2022 ). Other isolates associated with leaf and stem spots, blight, twig dieback, and fruit mold were documented in the earlier literature ( Farr and Rossman, 2022 ).…”

Six Additions to the Genus Periconia (Dothideomycetes: Periconiaceae) from Graminaceous Plants in China

“…Conidia of Periconia species are globose to ellipsoidal, catenate or solitary, smooth or verruculose, and pale brown to brown [ 2 , 4 , 5 , 6 ]. Only five species have been reported to have sexual morphs, viz., P. didymosporum , P. homothallica , P. igniaria , P. prolifica, and P. pseudodigitata [ 7 , 8 ]. The sexual morph is characterized by scattered or grouped, globose ascomata with a central ostiole, hyaline periphyses, 8-spored asci, and broadly fusiform, 1-septate, hyaline and smooth ascospores with an entire sheath [ 7 , 8 , 9 , 10 ].…”