Stemphylium Leaf Blight of Welsh Onion (Allium fistulosum): An Emerging Disease in Sanxing, Taiwan.

Welsh onion (Allium fistulosum L.) is one of the main and oldest vegetable crops grown in Taiwan. A severe epidemic of leaf blight in Welsh onion caused by a Stemphylium-like pathogen was found in Sanxing, Taiwan, from 2018 to 2020. However, correct species identification, biology, and control of Stemphylium leaf blight (SLB) of Welsh onion are not well-established. Therefore, the main objective of this study was to investigate the causal agent of SLB in Sanxing and evaluate the in vitro sensitivity of Stemphylium-like pathogen to commonly used fungicides. A phylogenetic analysis based on combining the internal transcribed spacer (ITS) region and glyceraldedyhe-3-phosphate dehydrogenase (gapdh) and calmodulin (cmdA) gene sequences together with morphological features identified that S. vesicarium is associated with SLB in Sanxing. When inoculated onto Welsh onion leaves, the isolates caused symptoms identical to those observed in the field; therefore, S. vesicarium was reisolated and Koch's postulates were confirmed. We observed a higher incidence of SLB symptoms on the oldest leaves compared with younger leaves. The maximum and minimum temperatures for in vitro mycelial growth and conidial germination (%) of S. vesicarium were 20 to 30°C and 5°C, respectively. Sixteen fungicides were tested for their effectiveness to reduce the mycelial growth and conidial germination of S. vesicarium in vitro. Boscalid plus pyraclostrobin, fluopyram, fluxapyroxad, and fluxapyroxad plus pyraclostrobin were highly effective at reducing mycelial growth and conidial germination in S. vesicarium. However, strobilurin fungicides (azoxystrobin and kresoxim-methyl) commonly used in Welsh onion production in Sanxing were ineffective. This study discusses the emergence of SLB caused by S. vesicarium in the foliar disease complex affecting Welsh onion and the management of the disease using fungicides with different modes of action in Taiwan. The research will support the sustainable management of SLB in Sanxing, Taiwan; however, further field assessments of the fungicides are warranted.

Two novel freshwater hyphomycetes, in Acrogenospora (Minutisphaerales, Dothideomycetes) and Conioscypha (Conioscyphales, Sordariomycetes) from Southwestern China.

Freshwater fungi are highly diverse in China and frequently reported from submerged wood, freshwater insects, herbaceous substrates, sediments, leaves, foams, and living plants. In this study, we investigated two freshwater species that were collected from Yunnan and Guizhou provinces in China. Detailed morphological analysis complemented by multi-gene phylogenetic analyses based on LSU, SSU, ITS, RPB2 and TEF1-α sequences data revealed them to be two new saprobic species, namely Acrogenosporaalangiisp. nov. and Conioscyphayunnanensissp. nov. in their asexual morphs. Additionally, Acrogenosporaalangiisp. nov. is reported for the first time as a freshwater ascomycete associated with the medicinal plant Alangiumchinense (Alangiaceae). Detailed morphological descriptions, illustrations and updated phylogenetic relationships of the new taxa are provided herein.

Hidden diversity of Pestalotiopsis and Neopestalotiopsis (Amphisphaeriales, Sporocadaceae) species allied with the stromata of entomopathogenic fungi in Taiwan.

Pestalotiopsissensu lato, commonly referred to as pestalotiopsis-like fungi, exhibit a broad distribution and are frequently found as endophytes, saprobes and pathogens across various plant hosts. The taxa within pestalotiopsis-like fungi are classified into three genera viz. Pestalotiopsis, Pseudopestalotiopsis and Neopestalotiopsis, based on the conidial colour of their median cells and multi-locus molecular phylogenies. In the course of a biodiversity investigation focusing on pestalotiopsis-like fungi, a total of 12 fungal strains were identified. These strains were found to be associated with stromata of Beauveria, Ophiocordyceps and Tolypocladium in various regions of Taiwan from 2018 to 2021. These strains were evaluated morphologically and multi-locus phylogenetic analyses of the ITS (internal transcribed spacer), tef1-α (translation elongation factor 1-α) and tub2 (beta-tubulin) gene regions were conducted for genotyping. The results revealed seven well-classified taxa and one tentative clade in Pestalotiopsis and Neopestalotiopsis. One novel species, Pestalotiopsismanyueyuanani and four new records, N.camelliae-oleiferae, N.haikouensis, P.chamaeropis and P.hispanica, were reported for the first time in Taiwan. In addition, P.formosana and an unclassified strain of Neopestalotiopsis were identified, based on similarities of phylogeny and morphology. However, the data obtained in the present study suggest that the currently recommended loci for species delimitation of pestalotiopsis-like fungi do not deliver reliable or adequate resolution of tree topologies. The in-vitro mycelial growth rates of selected strains from these taxa had an optimum temperature of 25 °C, but growth ceased at 5 °C and 35 °C, while all the strains grew faster under alkaline than acidic or neutral pH conditions. This study provides the first assessment of pestalotiopsis-like fungi, associated with entomopathogenic taxa.

Addition of Five Novel Fungal Flora to the Xylariomycetidae (Sordariomycetes, Ascomycota) in Northern Thailand.

The deviation of conventional fungal niches is an important factor in the implications of hidden fungal diversity and global fungal numbers. The Xylariomycetidae (Sordariomycetes, Ascomycota), which is also referred to as xylarialean taxa, has a wide range of species that demonstrate a high degree of variation in their stromatic characteristics, showing either conspicuous or inconspicuous forms. In this study, samples were collected while focusing on temporal and spatial parameters and substrate characteristics. Based on internal transcribed spacer (ITS), 28S large subunit rDNA (LSU), RNA polymerase II second largest subunit (RPB2), and ß-tubulin (TUB2) multigene phylogeny and morphology, five new species are introduced as Muscodor brunneascosporus, M. lamphunensis (Xylariaceae), Nigropunctata hydei, N. saccata (Incertae sedis), and Xenoanthostomella parvispora (Gyrotrichaceae). Plant substrates in the early stages of decay and attached to the host were feasible sample niches, with an emphasis on the collection of inconspicuous, hidden xylarialean species. The appearance of inconspicuous saprobic xylarialean forms during the rainy season may be linked to the change in nutritional mode, from endophytic mode during the dry season to saprobic in the wet. Therefore, it would be fascinating to concentrate future research on how seasonal fluctuations affect nutritional mode shifts, especially in northern Thailand, which would provide the optimal spatial characteristics. In order to establish a comprehensive linkage between endophytic and saprobic modes, it is imperative to have a substantial representation of endophytic isolate sequences resembling inconspicuous xylariaceous fungi within publicly accessible databases.

Morpho-Phylogenetic Evidence Reveals New Species of Fuscosporellaceae and Savoryellaceae from Freshwater Habitats in Guizhou Province, China.

During a survey of freshwater fungi in Guizhou Province, China, six hyphomycetous collections were founded on decaying wood from freshwater habitats. These taxa were characterized and identified based on morphology, phylogeny, and culture characteristics. Phylogenetic analysis of combined LSU, SSU, ITS, RPB2 and TEF1α sequence data indicated that our six isolates formed three distinct lineages and were distributed within Fuscosporellaceae and Savoryellaceae. They can be organized as three new species: Fuscosporella guizhouensis, Mucisporaaquatica and Neoascotaiwaniaguizhouensis. Fuscosporella guizhouensis and Neoascotaiwania guizhouensis have sporodochial conidiomata, micronematous conidiophores and dark brown conidia. The former possesses irregularly ellipsoidal conidia with apical appendages, while the latter has fusiform to obovoid conidia. Mucispora aquatica is characterized by macronematous conidiophores, elongating percurrently and dark brown, narrowly obovoid conidia. The detailed, illustrated descriptions and notes for each new taxon are provided, and the species of Fuscosporella is reported for the first time in China.

Insight into the Taxonomic Resolution of the Pleosporalean Species Associated with Dead Woody Litter in Natural Forests from Yunnan, China.

In the course of investigating the systematics of woody litter micromycete associates in Yunnan Province, China, we found one new species in Phaeoseptaceae, one new genus and three new species in Sulcatisporaceae from 16 specimens collected (ten collections of ascomycetous teleomorphs, four collections of hyphomycetous and two collections of coelomycetes anamorphs) from Ailaoshan, Chuxiong, Diqing, Honghe, Kunming, Lancang, Mengla and Yuxi in Yunnan Province. These taxonomic novelties were recognized with the aid of morphological comparisons and phylogenetic analyses of multiple gene sequences (non-translated loci and protein-coding regions). Pleopunctum menglaense sp. nov. is accommodated in Phaeoseptaceae (Pleosporales) based on its hyphomycetous anamorph, which is characterized by superficial sporodochia on the host surface, macronematous, mononematous, cylindrical, unbranched, aseptate, hyaline and smooth-walled conidiophores, monoblastic, terminal, hyaline conidiogenous cells, hyaline, muriform α conidia, and brown, muriform ß conidia with tri-lobed wing like basal cells. Kazuakitanaka gen. nov. (type: K. yuxiensis) is introduced in Sulcatisporaceae (Massarineae, Pleosporales) for a saprobic ascomycete with teleomorphic and anamorphic (coelomycetous) features. The teleomorph possesses globose to subglobose ascomata with acentric ostiole, a peridial wall of textura angularis to textura prismatica, cylindric-clavate, pedicellate asci with an ocular chamber, and 1-2-septate, hyaline, fusiform, guttulate ascospores with a distinct mucilaginous sheath. The anamorph features pycnidial conidiomata, phialidic, ampulliform to cylindrical, hyaline conidiogenous cells and ampulliform to cylindrical, one-to-three-septate, hyaline, guttulate conidia. Loculosulcatispora was known only from its anamorph of L. thailandica. We observed the teleomorph of Loculosulcatispora hongheensis sp. nov. and amended the generic description of Loculosulcatispora accordingly. Loculosulcatispora hongheensis is characterized by globose to subglobose ascomata with a central ostiole, a peridial wall of textura angularis to globosa, branched, septate, pseudoparaphyses, clavate asci with a short pedicel and a minute ocular chamber and hyaline, fusiform, 1-septate ascospores with a thick irregular mucilaginous sheath. This study provides some insights into the diversity of fungi on dead woody litter in terrestrial habitats.

Morphology Characterization, Molecular Identification, and Pathogenicity of Fungal Pathogen Causing Kaffir Lime Leaf Blight in Northern Thailand.

Thailand is known to be the largest producer of kaffir lime leaf products in the global market. In 2021, leaf blight was found on kaffir lime plants (Citrus hystrix DC.) in Lamphun Province of northern Thailand. This disease has been associated with significant economic losses. However, there have been no prior reports of leaf blight on kaffir lime plants in Thailand or anywhere else in the world. In this study, causal fungi were isolated from lesions of kaffir lime plants and a total of three fungal isolates were obtained. All causal fungi were identified as Lasiodiplodia chinensis based on morphological characteristics and the phylogenetic analysis of combined sequences of the internal transcribed spacer (ITS) of ribosomal DNA, the translation elongation factor 1-alpha (tef-1), ß-tubulin (tub), and RNA polymerase II subunit (rbp2) genes. Pathogenicity tests were conducted and the results revealed that all isolated fungi caused symptoms of leaf blight on inoculated leaves. This outcome was similar to symptoms that naturally occur and have been observed in the field. This is the first report on kaffir lime leaf blight caused by L. chinensis. Our study will provide information of high value for the development of effective strategies for the monitoring and prevention of this disease.

Reassessment of Dyfrolomyces and Four New Species of Melomastia from Olive (Olea europaea) in Sichuan Province, China.

Pleurotremataceae species are saprobes on decaying wood in terrestrial, mangrove, and freshwater habitats. The generic boundary of the family has traditionally been based on morphology. All genera of Pleurotremataceae have a high degree of morphological overlap, of which the generic circumscription of Melomastia and Dyfrolomyces has not been well resolved. Thus, the delimitation of genera has always been challenging. Melomastia traditionally differs from Dyfrolomyces in having 2-septate, oblong, with obtuse-ends ascospores. These main characteristics have been used to distinguish Melomastia from Dyfrolomyces for a long time. However, the above characteristics sometimes overlap among Dyfrolomyces and Melomastia species. Based on the morphology and multigene phylogeny with newly obtained data, we synonymized Dyfrolomyces under Melomastia following up-to-date results. Four novel species (i.e., Melomastia fusispora, M. oleae, M. sichuanensis and M. winteri) collected from the dead branches of Olea europaea L. in Chengdu Olive Base, Sichuan Province in China are introduced based on detailed morphological characterization and phylogenetic analyses of sequences based on nuclear ribosomal (LSU and SSU) and protein-coding gene (tef1-α). The 11 new combinations proposed are Melomastia aquatica (=Dyfrolomyces aquaticus), M. chromolaenae (=D. chromolaenae), M. distoseptata (=D. distoseptatus), M. mangrovei (=D. mangrovei), M. marinospora (=D. marinosporus), M. neothailandica (=D. neothailandicus), M. phetchaburiensis (=D. phetchaburiensis), M. sinensis (=D. sinensis), M. thailandica (=D. thailandica), M. thamplaensis (=D. thamplaensis) and M. tiomanensis (=D. tiomanensis).

Brunneosporopsis yunnanensis gen. et sp. nov. and Allocryptovalsa xishuangbanica sp. nov., New Terrestrial Sordariomycetes from Southwest China.

Three fungal taxa were collected on dead branches of wood during fieldwork in Sichuan and Yunnan Provinces, China. The new generic name Brunneosporopsis gen. nov. and species B. yunnanensis sp. nov. are introduced for a novel taxon characterized by globose to subglobose and dark olivacous-brown conidia. Phylogenetic analyses based on combined LSU, SSU and tef1-α loci strongly support the monophyly of this taxon and place it in the subclass Diaporthomycetidae. It could not be assigned to any currently recognized families in the subclass and was, therefore, placed in the Diaporthomycetidae genera incertae sedis. A second taxon represents a new species in Allocryptovalsa based on an analysis of the sequence datasets of ITS and btub loci of the novel, brown-spored sexual morphic species. This taxon is described here as A. xishuangbanica sp. nov. An interesting hypocrealean fungus producing synnemata, Stilbocrea gracilipes, was collected from dead wood of an unknown host from Sichuan Province and is reported here, with asexual morph from both the host and culture as well as LSU, ITS, tef1-α, rpb2 and rpb1 sequence data.