Botryosphaerialean fungi associated with woody oil plants cultivated in Sichuan Province, China.

Woody oil plants are important economic trees which are widely cultivated and distributed throughout China. Surveys conducted during 2020 and 2021 on several woody oil plantations from five regions of Sichuan Province, China, revealed a high diversity of Botryosphaerialean fungi. The identification of 50 botryosphaeriaceous isolates was carried out based on both morphology and multi-gene phylogenetic analysis of internal transcribed spacer region (ITS), translation elongation factor 1-alpha gene (tef1) and ß-tubulin gene (tub2). This allowed the identification of twelve previously known Botryosphaeriales species: Aplosporellaprunicola, A.ginkgonis, Barriopsistectonae, Botryosphaeriadothidea, Bo.fabicerciana, Diplodiamutila, Di.seriata, Dothiorellasarmentorum, Neofusicoccumparvum, Sardiniellaguizhouensis, Sphaeropsiscitrigena, and Sp.guizhouensis, and four novel species belonging to the genera Diplodia and Dothiorella, viz. Di.acerigena, Di.pistaciicola, Do.camelliae and Do.zanthoxyli. The dominant species isolated across the surveyed regions were Botryosphaeriadothidea, Sardiniellaguizhouensis and Diplodiamutila, representing 20%, 14% and 12% of the total isolates, respectively. In addition, most isolates were obtained from Pistaciachinensis (14 isolates), followed by Camelliaoleifera (10 isolates). The present study enhances the understanding of Botryosphaeriales species diversity on woody oil plants in Sichuan Province, China.

Morpho-Phylogenetic Evidence Reveals Novel Species and New Records of Botryosphaeriaceae in China and Thailand.

Species in the Botryosphaeriaceae are common plant pathogens, endophytes, and saprobes found on a variety of mainly woody hosts. Botryosphaeriaceae is a high-profile fungal family whose genera have been subjected to continuous revisions in recent years. Surveys conducted during 2019 and 2020 on several decaying woody hosts (from dead arial twigs, branches, stems, bark, and seed pods) in China and Thailand revealed a high diversity of Botryosphaeriaceae fungi. Identification of 16 Botryosphaeriaceae isolates was carried out based on both morphological characteristics and phylogenetic analyses of combined ITS, LSU, tef1-α, and tub2 sequence data. Four novel species (Dothiorella ovata, Do. rosacearum, Do. septata, and Lasiodiplodia delonicis) and seven previously known species (Botryosphaeria fujianensis, Diplodia mutila, Di. seriata, L. crassispora, L. mahajangana, Macrophomina euphorbiicola and Sphaeropsis eucalypticola) were identified while new hosts and geographical records were reported. This study indicates that the fungal family Botryosphaeriaceae seems to be common and widespread on a broad range of hosts in China and Thailand.

Identification and Pathogenicity of Pestalotiod Fungi Associated with Woody Oil Plants in Sichuan Province, China.

Pestalotiod fungi are associated with a wide variety of plants worldwide and occur as endophytes, pathogens, and saprobes. The present study provides an updated phylogeny for genera Neopestalotiopsis, Pestalotiopsis, and Seiridium using fresh collections from woody oil plants (Camellia oleifera, Olea europaea, Paeonia suffruticosa, Sapium sebiferum, and Vernicia fordii) in Sichuan Province, China. We coupled morphology and combined sequence data analyses of ITS, tub2, and tef1-α for Neopestalotiopsis and Pestalotiopsis, with ITS, LSU, tub2, tef1-α, and rpb2 for Seiridium. Three novel species of Neopestalotiopsis (N. mianyangensis, N. paeonia-suffruticosa, N. terricola) and three of Seiridium (S. guangyuanum, S. vernicola, S. oleae), were found. Three other species, Pestalotiopsis kenyana, Seiridium ceratosporum, and S. rosarum were identified and reported as new records. All isolated species are fully described and illustrated. Additionally, the sexual morph of Pestalotiopsis kenyana is described for the first time. Pathogenicity tests revealed that Neopestalotiopsis mianyangensis, N. paeonia-suffruticosa, N. terricola, Pestalotiopsis kenyana, Seiridium guangyuanum, S. vernicola, and S. oleae are pathogenic on detached olive leaves.

Occurrence and Morpho-Molecular Identification of Botryosphaeriales Species from Guizhou Province, China.

Botryosphaeriales is an important order of diverse fungal pathogens, saprobes, and endophytes distributed worldwide. Recent studies of Botryosphaeriales in China have discovered a broad range of species, some of which have not been formerly described. In this study, 60 saprobic isolates were obtained from decaying woody hosts in southwestern China. The isolates were compared with other species using morphological characteristics, and available DNA sequence data was used to infer phylogenetic analyses based on the internal transcribed spacer (ITS), large subunit rRNA gene (LSU), and translation elongation factor 1-α (tef) loci. Three novel species were illustrated and described as Botryobambusa guizhouensis, Sardiniella elliptica, and Sphaeropsis guizhouensis, which belong to rarely identified genera within Botryosphaeriaceae. Botryobambusa guizhouensis is the second species identified from the respective monotypic genus. The previously known species were identified as Aplosporella hesperidica, Barriopsis tectonae, Botryosphaeria dothidea, Diplodia mutila, Di. neojuniperi, Di. pseudoseriata, Di. sapinea, Di. seriata, Dothiorella sarmentorum, Do. yunnana, Lasiodiplodia pseudotheobromae, Neofusicoccum parvum, Sardiniella celtidis, Sa. guizhouensis, and Sphaeropsis citrigena. The results of this study indicate that numerous species of Botryosphaeriales are yet to be revealed in southwestern China.

https://botryosphaeriales.org/, an online platform for up-to-date classification and account of taxa of Botryosphaeriales.

Fungi are eukaryotes that inhabit various ecosystems worldwide and have a decomposing effect that other organisms cannot replace. Fungi are divided into two main groups depending on how their sexual spores are formed, viz. Ascomycota and Basidiomycota. The members of Botryosphaeriales (Dothideomycetes, Ascomycota) are ubiquitous. They are pathogenic on a wide range of hosts, causing diverse diseases including dieback, canker, leaf spots and root rots and are also reported as saprobes and endophytes worldwide. As an important fungal group, of which most are plant pathogens, it is necessary to organize data and information on Botryosphaeriales so that scientific literature can be used effectively. For this purpose, a new website, https://botryosphaeriales.org is established to gather all published data together with updates on the present taxonomy of Botryosphaeriales. The website consists of an easy-to-operate searching system and provides an up-to-date classification together with accounts of Botryosphaeriales taxa, including colour illustrations, descriptions, notes and numbers of species in each genus, as well as their classification. Thus, readers will be able to obtain information on botryosphaerialean taxa through this platform. Database URL: https://botryosphaeriales.org/.

Unravelling Diaporthe Species Associated with Woody Hosts from Karst Formations (Guizhou) in China.

Though several Diaporthe species have been reported in China, little is known about the species associated with nature reserves in Guizhou province. During a survey of fungi in six nature reserves in Guizhou province of China, thirty-one Diaporthe isolates were collected from different woody hosts. Based on morphology, culture characteristics and molecular phylogenetic analysis, these isolates were characterized and identified. Phylogenetic analysis of internal transcribed spacer region (ITS), combined with translation elongation factor 1-alpha (tef), ß-tubulin (tub), calmodulin (cal) and histone H3 (his) gene regions identified five known Diaporthe species and seven distinct lineages representing novel Diaporthe species. The details of five known species: Diaporthe cercidis, D. cinnamomi, D. conica, D. nobilis and D. sackstonii are given and the seven new species D. constrictospora, D. ellipsospora, D. guttulata, D. irregularis, D. lenispora, D. minima, and D. minusculata are introduced with detailed descriptions and illustrations. This study revealed a high diversity of previously undescribed Diaporthe species associated with woody hosts in various nature reserves of Guizhou province, indicating that there is a potential of Diaporthe species remains to be discovered in this unique landform (Karst formations) in China. Interestingly, the five known Diaporthe species have been reported as pathogens of various hosts, and this could indicate that those newly introduced species in this study could be potentially pathogenic pending further studies to confirm.

Endophytic Diaporthe Associated With Citrus grandis cv. Tomentosa in China.

Diaporthe species are associated with Citrus as endophytes, pathogens, and saprobes worldwide. However, little is known about Diaporthe as endophytes in Citrus grandis in China. In this study, 24 endophytic Diaporthe isolates were obtained from cultivated C. grandis cv. "Tomentosa" in Huazhou, Guangdong Province in 2019. The nuclear ribosomal internal transcribed spacer (ITS), partial sequences of translation elongation factor 1-α (tef1), ß-tubulin (tub2), and partial calmodulin (cal) gene regions were sequenced and employed to construct phylogenetic trees. Based on morphology and combined multigene phylogeny, eleven Diaporthe species were identified including two new species, Diaporthe endocitricola and D. guangdongensis. These are the first report of D. apiculata, D. aquatica, D. arecae, D. biconispora, D. limonicola, D. masirevicii, D. passifloricola, D. perseae, and D. sennae on C. grandis. This study provides the first intensive study of endophytic Diaporthe species on C. grandis cv. tomentosa in China. These results will improve the current knowledge of Diaporthe species associated with C. grandis. The results obtained in this study will also help to understand the potential pathogens and biocontrol agents and to develop a platform in disease management.

High Genetic Diversity and Species Complexity of Diaporthe Associated With Grapevine Dieback in China.

Grapevine trunk diseases have become one of the main threats to grape production worldwide, with Diaporthe species as an emerging group of pathogens in China. At present, relatively little is known about the taxonomy and genetic diversity of Chinese Diaporthe populations, including their relationships to other populations worldwide. Here, we conducted an extensive field survey in six provinces in China to identify and characterize Diaporthe species in grape vineyards. Ninety-four isolates were identified and analyzed using multi-locus phylogeny. The isolates belonged to eight species, including three novel taxa, Diaporthe guangxiensis (D. guangxiensis), Diaporthe hubeiensis (D. hubeiensis), Diaporthe viniferae (D. viniferae), and three new host records, Diaporthe gulyae (D. gulyae), Diaporthe pescicola (D. pescicola), and Diaporthe unshiuensis (D. unshiuensis). The most commonly isolated species was Diaporthe eres (D. eres). In addition, high genetic diversity was observed for D. eres in Chinese vineyards. Haplotype network analysis of D. eres isolates from China and Europe showed a close relationship between samples from the two geographical locations and evidence for recombination. In comparative pathogenicity testing, D. gulyae was the most aggressive taxon, whereas D. hubeiensis was the least aggressive. This study provides new insights into the Diaporthe species associated with grapevines in China, and our results can be used to develop effective disease management strategies.

Comparative genome and transcriptome analyses reveal adaptations to opportunistic infections in woody plant degrading pathogens of Botryosphaeriaceae.

Botryosphaeriaceae are an important fungal family that cause woody plant diseases worldwide. Recent studies have established a correlation between environmental factors and disease expression; however, less is known about factors that trigger these diseases. The current study reports on the 43.3 Mb de novo genome of Lasiodiplodia theobromae and five other genomes of Botryosphaeriaceae pathogens. Botryosphaeriaceous genomes showed an expansion of gene families associated with cell wall degradation, nutrient uptake, secondary metabolism and membrane transport, which contribute to adaptations for wood degradation. Transcriptome analysis revealed that genes involved in carbohydrate catabolism, pectin, starch and sucrose metabolism, and pentose and glucuronate interconversion pathways were induced during infection. Furthermore, genes in carbohydrate-binding modules, lysine motif domain and the glycosyl hydrolase gene families were induced by high temperature. Among these genes, overexpression of two selected putative lignocellulase genes led to increased virulence in the transformants. These results demonstrate the importance of high temperatures in opportunistic infections. This study also presents a set of Botryosphaeriaceae-specific effectors responsible for the identification of virulence-related pathogen-associated molecular patterns and demonstrates their active participation in suppressing hypersensitive responses. Together, these findings significantly expand our understanding of the determinants of pathogenicity or virulence in Botryosphaeriaceae and provide new insights for developing management strategies against them.

Taxonomy and phylogeny of Laburnicola gen. nov. and Paramassariosphaeria gen. nov. (Didymosphaeriaceae, Massarineae, Pleosporales).

Laburnicola gen. nov., with four new species, Paramassariosphaeria gen. nov., with a new species and Montagnula saikhuensis sp. nov. are introduced in this paper. The phylogeny of these taxa and genera of Didymosphaeriaceae are resolved based on analysis of combined LSU, SSU, and ITS sequence data. Laburnicola is characterized by obpyriform, immersed ascomata, with a peridium fused to the host tissues, long pedicellate asci and ellipsoidal to fusoid ascospores, whose central cells have longitudinal septa and a rugged surface. Paramassariosphaeria is characterized by globose to subglobose ascomata, papillate ostioles, a peridium comprising pseudoparenchymatous cells of textura angularis, cylindric-clavate to clavate, pedicellate asci and brown, curved-fusoid ascospores, with multiple transverse septa and a mucilaginous sheath. Montagnula saikhuensis has immersed ascomata, with a peridium fused to the host tissues, long pedicellate asci and blackish brown, ellipsoidal ascospores with a single septum. The relationship of these taxa with other Didymosphaeriaceae species is discussed based on comparative morphology and phylogenetic analysis. Munkovalsaria appendiculata and Munkovalsaria donacina are transferred to the genus Montagnula.

Morphological and molecular characterisation of Diaporthe species associated with grapevine trunk disease in China.

Trunk diseases in grapevine (Vitis spp.) are major problems in the wine and table-grape industries reducing the productivity, quality and longevity of vineyards. Species of Diaporthe are important fungal pathogens of grapevine trunk disease worldwide. A survey of 14 grape vineyards located in different provinces of China was yielded Diaporthe isolates associated with symptomatic grapevine wood. These isolates were identified based on morphology and a combined data matrix of rDNA ITS, partial sequences of translation elongation factor 1-α (EF 1-α), ß-tubulin (TUB) and calmodulin (CAL) gene regions. Four species of Diaporthe were identified, which included Diaporthe eres, Diaporthe hongkongensis, Diaporthe phaseolorum and Diaporthe sojae. All isolates of Diaporthe caused disease on detached grape shoots in pathogenicity experiments but differed in virulence. The incidence in local vineyards and the pathogenicity results indicate that D. eres is an important pathogen of grapevine in Chinese vineyards, where it may significantly limit grape production. This is the first detailed report of Diaporthe species associated with grapevine trunk diseases in China with morphology, pathogenicity and molecular data.