Nuclear Ribosomal Large Subunit Research Articles

Infundibulicybe swatica (Basidiomycota, Agaricales), a new species from Pakistan

A new species, Infundibulicybe swatica is described and illustrated from District Swat, Khyber Pakhtunkhwa, Pakistan. The new taxon is characterized by pale yellow to pale yellow brown to brown pileus with a dark brown center; a bicolorous stipe, white at the apex and pale yellow brown hues at the base; hyaline, lacrymoid to sub-lacrymoid, small, inamyloid basidiospores (6.5 × 4.2 µm); and the absence of hymenial cystidia. Molecular phylogenetic analyses based on nuclear ribosomal Internal Transcribed Spacer (ITS) and nuclear ribosomal Large Subunit (LSU) regions confirm the novelty of the taxon.

First report of basal stem rot on sugarcane (var. Badila) caused by Sclerotium rolfsii in China.

Badila (Saccharum officinarum) is one of the important chewing cane in south China. During the year 2019-2020, as much as 60.2%-87.5% of sugarcane plants stem showed red rot developments were observed in the fields of Yongning District, Nanning city, Guangxi province. Symptomatic plants showed red rot at basal stem nodes and sheath, when the disease serious, the epidermis and aerial roots decomposed and exfoliated, then formed sclerotiums, the upper stem also occurred the symptom. Infected plant tissues were dissected into small pieces with 0.1 × 0.1cm in size and surface sterilized in 0.1% HCl2 for 2 min, followed by 75% ethanol for 30 s, rinsed three times with sterile distilled water. Then the tissues were placed onto potato dextrose agar (PDA) plates and incubated at 25 °C for 3 days. Numerous white globoid sclerotia were formed on PDA after 5 days of growth. The sclerotia (2 to 3 mm in diameter) were white at first and then gradually turned dark brown. Aerial mycelia usually formed many narrow hyphal strands 4 to 9 μm wide. Five uniform isolates were obtained from diseased sugarcane plants. Pathogenicity of representative strain W1 was confirmed by inoculating 120-day-old Badila plants grown in field. Five plants were inoculated with colonized agar discs (6mm in diameter) by applying toothpick tips to the lower part of the stem. Five non-inoculated plants served as control. The inoculated and non-inoculated plants were sprayed sterile water then incubated with plastic film for maintained high moisture. All the plants were placed inside of a growth chamber at 26 ± 2°C with a 14-h photoperiod and 80% relative humidity. All inoculated plants showed red rot at stem and sheath after 2 weeks, whereas the control plants were symptomless. By the third week, mycelium and sclerotia developed on the crown on the inoculated plants. The fungus was re-isolated from the artificially inoculated plants. To confirm the species-level identification, partial of the ribosomal DNA internal transcribed spacer (ITS), mitocondrial small subunit (SSU), and nuclear ribosomal large subunit (LSU) regions of representative strain W1 were amplified and sequenced using the primers pairs ITS1/ITS4 (White et al. 1990), ITS-Fu-F /ITS-Fu-R and SRLSU1//SRLSU2 (Kumar et al., 2016), respectively. The resulting ITS, SSU and LSU sequences were deposited in GenBank (GenBank accession no. MW620994, MW617878, and MW617872) and shared 99.42%, 100% and 100% sequence identity with Athelia rolfsii isolate (JN017199, OM319631, and MT225781). Phylogenetic analysis conducted with neighbor-joining (NJ) method using MEGA6.0 revealed that the isolate share a common clade with reference sequence of A. rolfsii in GenBank Data Library. Based on morphological and molecular characteristics, the fungus was identified as A. rolfsii (anamorph: Sclerotium rolfsii) (Paul et al. 2017; Paparu et al. 2020). Although S. rolfsii has been reported causing sugarcane sett rot in Australia (Bhuiyan et al., 2019) and seedlings of sugarcane in Indian (Gopi et al., 2023), as we know, this is the first report of sugarcane basal stem rot disease caused by this fungus in China. This study will be helpful for the prevention and control sugarcane basal stem rot in the future.

Two new species of Phylloporus (Boletaceae) from the montane cloud forest of Eastern Mexico

Phylloporus represents a group of fungi belonging to the lamellate Boletineae, which despite not having been exhaustively documented worldwide, most of its species have been recognized in tropical regions. The present research proposes the description of Phylloporus montanus and P. xalapensis as new species to science. Both were discovered in Mexico through a sampling focused on the study of the genus in the montane cloud forest from the east region of the country. The new species were recognized based on a morpho-anatomic study and supported by a phylogeny inferred from internal transcribed spacer (ITS rDNA), nuclear large ribosomal subunit (nLSU) and translation elongation factor 1-alpha (TEF1) sequences. Descriptions of each species are detailed, accompanied by illustrations and photographs.

First European records of Puccinia modiolae and P. platyspora, two native South American rust fungi, and new observations on their life cycle and morphology

ABSTRACT This paper reports the South American rust fungi Puccinia modiolae and P. platyspora (Pucciniales/Uredinales) as new alien species of the European rust funga. Puccinia modiolae is presently known from Switzerland and Germany, P. platyspora from Switzerland, Germany, and France. The records of P. platyspora are the first ones from outside South America. The specimens were identified by teliospore characters and sequences of the nuclear ribosomal DNA (internal transcribed spacer 2 and domains D1–D2 of the nuclear ribosomal large subunit) and the mitochondrial CO3 (cytochrome c oxidase III) gene. Puccinia modiolae and P. platyspora have been recorded so far in Europe on members of the genera Alcea, predominantly on Alcea rosea, Althaea, and Malva of the Malvaceae, subfam. Malvoideae. Alcea rosea is host of both species and shared also with the common mallow rust, P. malvacearum, allowing for mixed infections. The plant is commonly grown as an ornamental and may play a major role for the spread of the alien Malvaceae rust fungi. It was observed for the first time that P. platyspora can produce spermogonia and aecidium-type aecia, suggesting phenotypic plasticity regarding the formation of spore states. The observed spermogonia mainly remained closed and did not liberate spermatia. They produced telio- and aeciospores besides spermatia in their cavity and eventually converted entirely into telia or, rarely, into aecidium-like sori. Small clusters of aeciospores and peridial cells were commonly found hidden in the telial plectenchyma, and well-developed aecidium-type aecia provided with a peridium developed rarely in the center of mature telia. Spermogonia belonging to group V type 4 were found in P. malvacearum, which is generally supposed to lack spermogonia. Some spermogonia produced only spermatia in their cavity; others formed spermatia and teliospores, and some eventually converted into telia.

Four new species of Cortinariaceae (Agaricales) from Northwestern China.

Cortinariaceae, which belongs to the Agaricales order, is a globally recognized family, known for its high species diversity. Eight internal transcribed spacer (ITS) and nuclear large ribosomal subunit (LSU) sequences were newly generated, and phylogenetic analyses were performed by combining ITS and LSU datasets. Four species were identified as forming four independent lineages with robust support in phylogenies based on both datasets. These new species in the taxa, Cortinarius gansuensis, Cortinarius tricholomoidus, Cortinarius vinoso-griseum, and Phlegmacium subcalyptratum from Northwestern China are described and illustrated based on morphological and molecular evidence. Cortinarius gansuensis is characterized by a convex and brownish vinaceous pileus, generative hyphae with clamp connections, and ellipsoid basidiospores (8.5-10.6 μm × 5.4-6.8 μm); Cortinarius tricholomoidus is characterized by a broadly umbonate and snuff brown pileus, generative hyphae with clamp connections, and broadly ellipsoid to subglobose basidiospores (7.4-8.5 μm × 6.2-7.3 μm); Cortinarius vinoso-griseum is characterized by a violaceous gray pileus, generative hyphae with clamp connections, and smaller basidiospores (7.5-9.7 μm × 5.6-7.8 μm); and Phlegmacium subcalyptratum is characterized by a small and apricot-orange pileus, generative hyphae with clamp connections, and fusiform basidiospores (10.0-12.7 μm × 5.6-6.8 μm). Full descriptions, illustrations, and results of phylogenetic analyses of the four species along with discussions on related species are provided.

Morphological and molecular identification of two new Marasmiellus species (Omphalotaceae, Agaricales) from Thailand.

Marasmiellus (Omphalotaceae, Agaricales) specimens collected in Thailand were investigated based on morphological characteristics and molecular phylogenetic analyses. In the present study, two species are introduced as new to science, namely Marasmiellusthailandicus and M.minutisporus. Phylogenetic analyses were carried out based on the internal transcribed spacer (nrITS) and nuclear ribosomal RNA large subunit (nrLSU) regions, and the results revealed that the two new taxa are distinct species within Marasmiellus. Another specimen was identified as M.scandens and is reported for the first time with morphology and molecular data from Thailand. Descriptions, illustrations, and phylogenetic results are provided. In addition, M.diaphanus and M.colocasiae are proposed as new combinations of Collybiopsisdiaphana and Paramarasmiuscolocasiae, respectively, based on the phylogenetic evidence.

Addition to the genus Harmajaea (Agaricales, Pseudoclitocybaceae): a new and a known species from China

A new species, Harmajaea xizangense, discovered in Tibet, China, is illustrated and described based on morphological and molecular data. Morphologically, H. xizangense is mainly characterized by its small pileus, relatively larger and longer spores, and unique geographical distribution. Phylogenetic analyses were performed based on nucleotide sequences of four molecular loci: the internal transcribed spacer (ITS), the nuclear ribosomal large subunit (nrLSU), the DNA-directed RNA polymerase II subunit 2 (RPB2), and the translation elongation factor (TEF1-α). The results indicated that the specimens belonged to the genus Harmajaea, occupying an isolated position in the phylogenetic trees. Furthermore, three collections of H. harperi are introduced for the first time from Liaoning Province of China. This study provides full descriptions, color illustrations, and phylogenetic trees of the two Harmajaea species.

First Report of Polygonatum kingianum Leaf Spot Caused by Alternaria alternata in Kunming, China.

Polygonatum kingianum Coll. et Hemsl., a Polygonatum species in the Asparagaceae family, plays an important role in Chinese herbal medicine (Zhao et al. 2018). P. kingianum is widely planted in the Southwestern China. In September 2023, we observed a leaf spot of P. kingianum with disease incidence of 100%, and disease index reached 60 in commercial plantings in Kunming, Yunnan province, China (24.3610°N, 102.3740°E). In the initial stage of infection, symptoms manifested as a small circular brown spot. As the spots gradually expanded, they formed oval to irregular shaped lesions with grayish-white or dark-brown borders. Progressively the entire leaf withered and died. For identification of the causal agent of the leaf spot, leaf sections (5×5 mm2) were cut from the margin of the lesion and soaked in 75% ethanol for 10 s, 1% sodium hypochlorite for 3 min, washed with sterile distilled water, dried on sterilized tissue paper and placed on potato dextrose agar (PDA). The Petri dishes were then incubated at 28℃ for 3 days with a 12-h photoperiod. A predominant fungus was isolated from 95% of the samples. Three monosporic isolates were screened using a single-spore isolation method. After 4 days of incubation the colonies were white, after 7 days turned yellow-white. Conidia were black-brown, oblong or fusiform, with 3-7 transverse septa and 0-3 longitudinal septa, with dimensions of 19.5 to 49.5 × 8.7 to 17.6 µm (n = 30). Total genomic DNA of these three isolates was extracted from mycelia by the cetyltrimethylammonium bromide (CTAB) protocol. The nucleotide sequences of the elongation factor 1-alpha (EF1α), nuclear ribosomal internal transcribed spacer (ITS), 28S nuclear ribosomal large subunit rRNA gene (LSU), 18S nuclear ribosomal small subunit rRNA gene (SSU), and the second largest subunit of nuclear DNA-directed RNA polymerase II (RPB2) gene regions were amplified using the primer pairs EF1-728F/EF1-986R (Carbone and Kohn 1999), ITS1/ITS4 (White et al. 1990), LR0R/LR5 (Schoch et al. 2012), NS1/NS4 (Schoch et al. 2012), and fRPB2-5F/fRPB2-7Cr (Liu et al. 1999), respectively. Amplicons were cloned in a pMDTM19-T vector (code no. 6013, Takara, Kusatsu, Japan) and bidirectionally sequenced. All three isolates had identical nucleotide sequences. Sequences from one isolate (PkF03) were deposited in GenBank. BLASTn analyses showed that sequences of EF1α (GenBank accession no. PP695240), ITS (PP694046), LSU (PP683406), SSU (PP683407), and RPB2 (PP695241) of isolate PkF03 were 99.6 (KP125134), 100 (KP124358), 100 (KP124510), 99.9 (KP124980), and 100% (KP124826), respectively, identical with Alternaria alternata (Fr.) Keissl. strain CBS 118815. Based on the nucleotide sequences of EF1α, ITS, LSU, SSU, and RPB2, a maximum likelihood phylogenetic tree was constructed using MEGAX with Tamura-Nei model. Isolate PkF03 was grouped in the same clade as A. alternata. According to the morphology and sequence analyses isolate PkF03 was identified as A. alternata (Woudenberg et al. 2013). To determine pathogenicity of isolate PkF03, a spore suspension (106 spores/mL) was sprayed on 1-year-old healthy leaves of P. kingianum. The control leaves were sprayed with sterile water. All plants were incubated at 28℃, 70% relative humidity, and a 12-h photoperiod. The pathogenicity tests were repeated three times with six plants in each treatment. Fifteen days post-inoculation, the inoculated leaves showed brown-yellow lesions, whereas the control leaves remained symptomless. A. alternata was reisolated from infected leaves. To our knowledge, this is the first report of A. alternata causing leaf spot on P. kingianum in Kunming, China. The results provide a scientific basis for prevention and control of the disease.

First Report of Didymella pomorum Causing Leaf Blight on Angelica sinensis in China.

Angelica sinensis (Oliv.) Diels, is a perennial herbaceous plant of the Umbelliferae family. It has a long history of cultivation and is highly valued as a traditional Chinese medicine in China (Zhang et al. 2012). In September 2023, leaf blight on A. sinensis with an average disease incidence of 56% was recorded in an approximately 6.7-ha production field in Lijiang, Yunnan province, China (26.8215°N, 100.2369°E). At first, small, chlorotic lesions appeared on the leaves. They subsequently increased in density and gradually merged, causing leaves to yellow and wither. Ultimately the blight casused death of the entire foliage. In order to identify the causal agent, cross-sectional segments (5×5 mm2) were cut from the edge of leaf lesions, surface disinfected with a 1% sodium hypochlorite solution for 3 min and rinsed three times with sterile distilled water. They were subsequently placed on potato dextrose agar (PDA) plates and incubated for 3 days under a 12-h photoperiod at 28℃. A total of ten isolates with similar morphological characteristics were obtained by single spore isolation. After 10 days of incubation on PDA, the colony morphology of these isolates was characterized by a brownish central area with a white edge. Aged colonies became wrinkled in the center of the colony. Conidia (n = 30) were elliptical and brown, with a size range of 4.11 to 6.55 μm (average 5.37±0.74 μm) × 3.17 to 4.62 μm (average 3.92±0.43 μm). Chlamydospores (n = 30) formed chains in series, spherical or elliptical in shape, ranging from yellow-brown to dark brown, with a size range of 12.30 to 13.70 μm (average 12.98±0.46 μm) × 4.20 to 5.30 μm (average 4.63±0.26 μm). The nuclear ribosomal internal transcribed spacer region (ITS), the second largest subunit of RNA polymerase II (RPB2), and the 28S nuclear ribosomal large subunit rRNA (LSU) region of two isolates were amplified with the primer pairs ITS1/ITS4 (White et al. 1990), fRPB2-5F/fRPB2-7cR (Liu et al. 1999), and LR0R/LR5 (Schoch et al. 2012), respectively. These amplicons were sequenced bidirectionally and assembled. The two isolates produced the same nucleotide sequences, and the sequences of a representative isolate (AsDp1) were deposited in GenBank. BLASTn analyses showed that the ITS (PP510616), RPB2 (PP526010), and LSU (PP550143) sequences of isolate AsDp1 were 100%, 99.66%, and 100% identical with those of Didymella pomorum ex-type isolate CBS 354.52 (MH857081, KT389616, and MH868616), respectively. A phylogenetic tree was constructed based on the ITS, RPB2, and LSU concatenated nucleotide sequences using the maximum likelihood method in MEGAX. Isolate AsDp1 was clustered with four D. pomorum isolates. According to the morphological and nucleotide sequences analyses, isolate AsDp1 was identified as D. pomorum (Chen et al. 2015). To determine pathogenicity, 1-year-old A. sinensis plants (approximately 20 cm tall) grown in 7-liter pots filled with sterilized field soil were sprayed until runoff with a 1×106 conidia/ml suspension of isolate AsDp1 onto the foliage, while control plants were sprayed with sterile water. All plants were cultivated under a 12-h photoperiod at 25℃. The pathogenicity tests were performed in triplicate with ten plants in each treatment. After fifteen days, numerous chlorotic lesions appeared on the leaves of all inoculated plants. The symptoms were similar to those found on naturally infected plants in the field, while the control plants remained asymptomatic. Subsequently, D. pomorum was reisolated from the diseased leaves, and the identity was confirmed based on its ITS sequence and morphological characteristics. D. pomorum causing stem canker on Rosa spp. was reported in Canada (Ilyukhin 2022). To our knowledge, this is the first report of D. pomorum causing leaf blight on A. sinensis in China. This etiological finding will potentially pave the way for the development of control strategies of this disease.

First Report of Neofusicoccum parvum Causing Fruit Rot on Psidium guajava in China.

Guava (Psidium guajava L.), a nutrient-rich and economically significant fruit, is extensively cultivated in southern China. In six continuous years (from 2018 to 2023), dark-purple rotted guava with sunken lesion were observed on guava trees (variety 'Zhenzhu', aged over 5 years) in Dongguan and Panyu districts, Guangdong Province. Annually, the incidence of fruit rot disease in the affected fields reached 30% to 50% and significantly reduced the yield and quality of harvest guava. The initial symptoms on the epicarp of the fruits were black, needle-like dots that rapidly spread, causing partial or complete fruit rot within two to three weeks. To identify the causative agent, six symptomatic fruits were collected from two different orchards. Samples of 0.5 cm³ were excised from the lesion margins of each fruit. These samples were surface-sterilized with 70% ethanol for 30 seconds, followed by 0.2% NaClO for 2-3 minutes, and rinsed in sterile water three times. The samples were then cultured on potato dextrose agar (PDA) at 25°C for five days. This process yielded eight fungal isolates with similar morphological. Initially, the colonies were white with dense aerial mycelium becoming dark gray after 4 to 5 days. The mycelia were septate and branched. No spores were observed on PDA. To induce spore formation, the isolates were cultured on water agar for 20 days. This process led to the production of hyaline, aseptate, ellipsoid conidia, which were thin-walled, smooth-surfaced, and measured 3.7-5.1 × 1.6-2.2 μm (n = 100). Three isolates, including at least one from each orchard (Np1, Np2, Np3), were selected for further analysis. Genomic DNA was extracted using Axygen MAG-FRAG-I-50 (Axygen Bio-Tek). The internal transcribed spacer of rDNAs (ITS), beta-tubulin (tub2), the nuclear ribosomal large subunit (LSU), and translation elongation factor 1-α (tef1-α) gene regions were amplified using the primers ITS1/4, Bt2a/Bt2b, LR5/LR0R, and EF1-728F/EF1-986R (Golzar and Burgess 2011) and sequenced. Sequence analysis using MEGA 7.0 (Kumar et al., 2018) revealed 100% similarity among the isolates. BLAST searches of the ITS, tub2, LSU, and tef1-α sequences (accession nos. MN907637, MT537938, MT528156, MT537939) showed the highest nucleotide similarities (99.24 to 100%) to Neofusicoccum parvum strains (Crous et al. 2006). A phylogenetic tree was constructed with MEGA 7.0 based on the nucleotide sequence tub2 using the maximum likelihood method. Pathogenicity tests on 10 healthy guava fruits using mycelium-inoculated and control fruits confirmed the causative agent. The inoculated fruits, maintained at 25°C under a 12-h light/dark cycle, exhibited symptoms identical to the field infections within four to seven days, while control fruits remained symptomless. The fungus, reisolated from the inoculated fruits, was morphologically identical to the original isolates, fulfilling Koch's postulates. In conclusion, based on molecular, morphological, and pathogenic analysis, N. parvum as the causal agent of the fruit rot disease on guava. Previously, N. parvum has been reported in association with fruit rot on Eriobotrya japonica and Juglans regia (Zhai et al. 2019; Chen et al. 2019). To our knowledge, this is the first report of N. parvum affecting guava in China.

Phylogenetics of the rust fungi (Pucciniales) of South Africa, with notes on their life histories and possible origins

ABSTRACT South Africa has an indigenous rust (Pucciniales) funga of approximately 460 species. This funga was sampled with species from as many genera as possible. The nuclear ribosomal large subunit (28S) region was amplified from samples representing 110 indigenous species, as well as the small subunit (18S) region and the cytochrome c oxidase subunit 3 (CO3) in some cases, and these were used in phylogenetic analyses. One new species is described, 12 new combinations made, six names reinstated, and two life history connections made. The life histories of this funga were summarized; it is dominated by species with contracted life histories. The majority of species are autoecious, with a small proportion being heteroecious. Of the autoecious species, many will likely be homothallic with no spermagonia. A shortened life history with homothallism allows for a single basidiospore infection to initiate a local population buildup under the prevailing unpredictable climatic conditions. Suggestions are made as to the possible origin of this funga based on the development of the modern South African flora. It is postulated that the rusts of South Africa are of relatively recent origin, consisting of three groups. Firstly, there is an African tropical element with members of the Mikronegerineae (Hemileia), the Sphaerophragmiaceae (Puccorchidium, Sphaerophragmium), and certain Uredinineae (Stomatisora). Their immediate ancestors likely occurred in the tropical forests of Africa during the Paleogene. Secondly, there is a pantropical element including the Raveneliaceae (e.g., Diorchidium, Maravalia, Ravenelia sensu lato, Uropyxis). This likely diversified during the Neogene, when the mimosoids became the dominant trees of the developing savannas. Thirdly, the Pucciniaceae invaded Africa as this continent pushed northward closing the Tethys Sea. They diversified with the development of the savannas as these become the dominant habitat in most of Africa, and are by far the largest component of the South African rust funga.

First Report on Apothecium Deformity of Morchella importuna Caused by Alternaria alternata in China.

Morel mushrooms (Morchella spp.) are highly regarded globally for their distinctive texture and savory flavor. In 2022, the cultivation area for morel mushrooms in China reached nearly 20,000 hectares, with predominant cultivars including M. sextelata, M. importuna and M. exima (Bian et al., 2024). In March 2022, however, deformities of friting bodies were observed in M. importna at morel mushroom farms in Huaihua city (28.43°N, 110.47°), China, with an incidence rate ranging from 5% to 10%. The disease symptoms begin with the invasion of the hymenium of morel mushroom by white cotton-like mycelia, ultimately resulting in halted fruiting body growth and the manifestation of anomalous fruiting body morphology. Infected samples were collected from the morel growers. Following sterilization with 75% ethanol of the surrounding tissue of infected samples, the white hyphae from the morel lesions were picked out using a dissecting needle, and incubated onto potato saccharose agar medium supplemented with 60 mg/L streptomycin at 25°C. Studies showed that seven out of nine fungal isolates exhibiting identical morphological features rapidly grew on the same culture medium described above, reaching a length of 75 mm in 4 to 5 days at 25°C. The white and thick hyphal colonies of these isolates gradually filled with brown spore powder. Generally, the conidia of the hyphal colonies were polyblastic with protrusions at the tips, measuring 75 to 165 × 36 to 50 μm (n = 30) in width and length, displaying colors varying from light reddish brown to grayish brown, and possessing one or five septa. To confirm the identity of the pathogen, the region of the internal transcribed spacer region (ITS), 28S nuclear ribosomal large subunit (LSU), and RNA polymerase II second largest subunit (rpb2) genes of the representative isolate H2 were amplified by PCR (Taguiam, et al. 2021). The generated ITS (OR338304), rpb2 (OR452112) and LSU (OR338334) from the isolate H2 had 98-100% similarity to the Alternaria alternata strains ATCC 6663 and CBS 880.95 in BLASTn analysis. ITS, rpb2 and LSU sequences were assembled using Sequence Matrix, and their homogeneity was assessed with PAUP (Vaidya et al., 2011). Bayesian (MrBayes-3.2.7a) and maximum-likelihood (RAxML1.3.1) methods, utilizing the best fit GTR+G+I model obtained from MrModeltest 2.3, were employed for phylogenetic analysis (Aveskamp et al. 2010). Based on morphological characteristics and phylogenetic analysis, the isolate H2 was identified as A. alternata. In the second year post-disease, disease-free morels, with a height of 3 cm, were cultivated in field greenhouses and used for test. A 15 ml suspension (1 × 106 conidia/ml) was applied to 15 young fruiting bodies and their corresponding substrate soil. The results showed that the reappearance of white cotton-like mycelia and deformed M. importuna fruiting bodies within 7 days post-inoculation with the spore suspension, as opposed to the controls. The isolates (H2-1, H2-2 and H2-3) were reisolated from the infected tissues and identified as A. alternata based on its morphological features and phylogenetic analyses. In this study, a similar investigation was previously conducted on cultivated quinoa (Chenopodium quinoa) in Eastern Denmark (Colque-Little et al., 2023). This study marks the first documentation of A. alternata causing deformities in M. importuna fruiting bodies. These deformities occur under conditions of high-temperature (>22°C) and high humidity (>88%). Our findings provide crucial insights for managing A. alternata in M. importuna cultivation in China.

New insights into the stipitate hydnoid fungi Sarcodon, Hydnellum, and the formerly informally defined Neosarcodon, with emphasis on the edible species marketed in Southwest China

Sarcodon and Hydnellum are two ectomycorrhizal genera of important ecological and economic value in Southwest China, and they are common in the free markets in this region. It was estimated that more than 1,500 tonnes of them were sold as edible per year, but there was little information about the taxonomic placements of these edible mushrooms sold in the markets. Traditional concepts of the two genera have also been challenged recently, and circumscription of Sarcodon and the informally defined clade “Neosarcodon” remained unresolved. In the present study, specimens collected in the field and purchased from the markets in Southwest China were analyzed based on morphological characters and DNA sequences. Phylogeny of the traditional Sarcodon s. lat. and Hydnellum s. lat. was reconstructed from the combined internal transcribed spacer (ITS), nuclear large ribosomal subunit (nLSU) and RNA polymerase II second largest subunit (RPB2) dataset based on expanded samples to reevaluate the taxonomic placements of the two genera. In the present molecular analyses, four distinct clades were recovered and strongly supported: Hydnellum, Neosarcodon, Phellodon and Sarcodon. Neosarcodon is formally introduced as a generic name to include nine species previously placed in Sarcodon, and the delimitation of Sarcodon is revised based on phylogenetic and morphological studies. Phylogenetic analyses also revealed an unexpected species diversity (17 phylogenetic species) of Sarcodon and Hydnellum in the markets; nine phylogenetic species of Sarcodon and eight of Hydnellum were uncovered from the samples collected in the markets. Eight species were resolved in the traditional S. imbricatus complex, with S. imbricatus s.str. being the most common edible stipitate hydnoid fungal species. Three of the edible Hydnellum species (H. edulium, H. subalpinum, and H. subscabrosellum), and five separated from the S. imbricatus complex (Sarcodon flavidus, S. giganteus, S. neosquamosus, S. nigrosquamosus, and S. pseudoimbricatus), are described as new. Three new Chinese records (H. illudens, H. martioflavum, and H. versipelle), and the notable S. imbricatus and S. leucopus are also reported.

Occurrence and identification of two Nothophoma species causing branch canker and leaf brown spot of walnut in China

In June 2020, branch canker and brown spot of leaves on walnut were observed in Qingyang, China. A total of five strains were isolated from symptomatic samples and verified for pathogenicity based on Koch’s Postulates, which showed that strains Hz4–1, Hz5–2, and Hy3–1 were the causative agents, and preliminarily identified them as members of the genus Nothophoma based on morphological characteristics. Subsequently, multi-locus phylogenetic analysis of the partial sequences of internal transcribed spacer (ITS), nuclear large ribosomal subunit (LSU), partial β-tubulin (TUB2), and RNA polymerase II second largest subunit (RPB2) showed that the three strains were clustered into two groups on the phylogenetic tree: strain Hz4–1 and Hz5–2 and Nothophoma quercina (CBS 6633.92) clustered into one branch with 84% support, while Hy3–1 and Nothophoma spiraeae (CFCC 53 929) clustered within a well-supported clade with a bootstrap value of 99%. As a result, combining morphological characteristics and multi-locus systematic analysis, the strains Hz4–1 and Hz5–2 were identified as N. quercina, and Hy3–1 was identified as N. spiraeae, which is the first report of N. spiraeae causing walnut disease in China.

First report of Powdery Mildew Caused by Podosphaera xanthii on Siraitia grosvenorii in Guizhou, China.

Swingle (Siraitia grosvenorii), a member of the Cucurbitaceae family, stands out as a distinctive plant with both economic and medicinal significance. In October 2023, severe powdery mildew were observed on S. grosvenorii in Guiyang City (26.50°N; 106.66°E), Guizhou Province, China. About 80 % of the plants in the greenhouse showed powdery mildew symptoms. Three infected plant samples were selected for morphological and molecular analysis (GZAAS 23-0801, GZAAS 23-0802 and GZAAS 23-0803). The voucher specimens are deposited in the Key Laboratory of Agricultural Biotechnology of Guizhou Province. The symptoms initially manifested as irregular to nearly circular, small yellow spots, with distinct depressions as well as surfaces covered in white mycelium. Over time, these spots gradually expanded and merged patches. In the final stages, the entire leaves turned into yellow and withered. Microscopic observations showed that fungal hyphae were septate, branched, and flexuous to straight and 5 to 9 µm wide, and appressoria were indistinct to slightly nipple-shaped. Conidia were hyaline and ellipsoid to oval with fibrosin bodies and measured 31 to 43 × 18 to 24 μm (n = 50) with a length/width ratio of 1.3 to 2.3. Conidiophores were unbranched, straight, 120 to 268 × 14 to 22 µm (n = 30), producing two to five immature conidia in chains. Foot cells of conidiophores were cylindrical, 39 to 84 × 8 to 14 μm (n = 30), followed by one to three short cells. Short cells were cylindrical, 12 to 32 × 8 to 15 μm (n = 50). The morphological characteristics were identical with the previous description of Podosphaera xanthii (Braun and Cook, 2012). Total DNA was extracted from conidia and mycelia by the Chelex method (Walsh et al., 1991). The ribosomal DNA internal transcribed spacer (ITS) and nuclear ribosomal large subunit (LSU) were amplified by using the primers ITS1/ITS4 (White et al., 1990) and LSU1/LSU2 (Scholin et al., 1994), respectively. The ITS (OR825802, OR825803 and OR825804, respectively) and LSU (OR825805, OR825806 and OR825807, respectively) sequences of three isolates, were deposited in GenBank. The BLAST results revealed that both the ITS and LSU region sequence were 100% identical to those of P. xanthii (ITS: MF043939, MG754404 and KJ698669; LSU: OQ061319, AB936277and OP218411). Phylogenetic analyses of ITS and LSU sequences showed that our three isolates were clustered with P. xanthii (KX842351, LC270782 and LC270779) with high statistical support (ML/MP/BI: 100%/97%/1.00). Combined with their morphological characteristics, these three isolates were identified as P. xanthii. Pathogenicity tests were performed by gently brushing conidia onto the leaves of five healthy S. grosvenorii plants. Five non-inoculated plants were used as the control. All plants were maintained in a greenhouse at 25 ± 2°C. One week after inoculation, similar symptoms were observed in the inoculated plants, whereas no symptoms occurred on the control plants. By microscopic observation, the fungus on the inoculated plants was morphologically identical to those on originally diseased plants. Powdery mildew caused by P. xanthii has been reported on Vernonia cinerea (Wu et al., 2023), Vigna unguiculata (Zhang et al., 2023), Cucumis melo (Meesam et al., 2023). To our knowledge, this is the first report of powdery mildew caused by P. xanthii on S. grosvenorii in Guizhou, China. The occurrence of powdery mildew on S. grosvenorii may pose a potential threat to its large-scale cultivation. The pathogen could become a threat to other Cucurbitaceae members in the future.

A taxonomic study of Fulvifomes (Hymenochaetales, Basidiomycota) in the Federated States of Micronesia and identification of two new species

Fulvifomes (Hymenochaetaceae) is a genus that was separated from Phellinus in the early 2000s based on internal transcribed spacer (ITS) and nuclear large ribosomal subunit (nLSU) analyses. Species recognition in the genus is challenging without molecular analysis due to general absence of discrete morphological characteristics. In this study, we examined Fulvifomes diversity in the Federated States of Micronesia (FS Micronesia), primarily found in the tropical and subtropical regions. Seven Fulvifomes species were confirmed: two new species, one unrecorded species and four species previously reallocated to Fulvifomes from other genera. We provide sequences including data on two protein-coding genes (RNA polymerase II; RPB2 and translation elongation factor-1 alpha; TEF1), nLSU and different conspecific ITS types.

Sparassis fanjingshanensis, a new species of Sparassidaceae from Fanjingshan National Nature Reserve in China

Sparassis fanjingshanensis is described as a new species of Sparassidaceae based on morphology and phylogenetic analyses in this study. It was found in Abies fanjingshanensis community of the massy dwarf forest to Fanjing Mountain, China, and this is the only site of its occurrence known to date. Phylogenetic analysis of the sequences based on the internal transcribed spacer (ITS), the nuclear ribosomal large subunit (LSU) and partial gene coding RNA polymerase subunit II (rpb2) indicated that Sparassis fanjingshanensis belonged to the genus Sparassis and it formed a novel monophyletic clade next to Sparassis subalpina. Sparassis fanjingshanensis can be distinctly distinguished by its large basidiomata and light-gray to light-khaki flabellae that is compactly arranged, entire, broadly spathulate, slightly contorted, surface glabrous, top margin undulate, smooth, stem with concentric ring ornamentation (similar to the annual rings of a tree). In total, up to now, four taxa have been found in East Asia: Sparassis cystidiosa f. labelliformis, Sparassis fanjingshanensis, Sparassis labelliformis and Sparassis subalpine.

First report of cobweb disease in Auricularia cornea caused by Hypomyces mycophilus in Guizhou, China.

Auricularia cornea is a widely cultivated mushroom in China, which has high medicinal values such as hemostaticity, analgesia, antioxidation and anti-tumor (Wu et al., 2019). In 2022, an investigation on edible mushroom diseases in Guizhou Province observed a suspected cobweb disease in an A. cornea growing factory, with up to 30% incidence. The pathogen first produced flocculent hyphae on the surface of the fruiting body of A. cornea, and then developed spider web-like aerial hyphae, covering the entire fruiting bodies. It hinders the normal growth of A. cornea, resulting in deformity and rot of the fruiting bodies. These symptoms seriously affect the quantity and quality of mushroom yields and cause huge economic losses. Three fungal isolates (GUCCX001, GUCCX002 and GUCCX003) were recovered from the diseased mushroom fruiting bodies and purified through single spore isolation. The colonies of three isolates spread rapidly on PDA, reaching 79-82 mm in seven days. The flocculent mycelium was whitish, and its reverse turned from yellowish to amber after 14 days. The branched conidiophores arising from aerial mycelia were septate and each cell contained several denticulate conidiogenous loci. Each denticle contained a single conidium. Conidia were observed at the tip of conidiophore branches and were 0-1-septate, oval or spherical, transparent, 5.2-11.3 × 11.7-18.7 μm (n = 35). Chlamydospores were visible as 3-4 thick-walled cells at the tip of lateral hyphal branches. Three isolates were tentatively identified as H. mycophilus based on their morphological characteristics similar to those described by Rogerson and Samuels (1993). The sequence of internal transcribed spacer (ITS) region (primers ITS5/ITS4) (Rehner and Samuels, 1994) and nuclear ribosomal large subunit (LSU) region (primers LR0R/LR5) (Vilgalys and Heste, 1990) of GUCCX001 (ITS: OP777905; LSU: OQ152071), GUCCX002 (ITS: OP862872; LSU: OQ152072) and GUCCX003 (ITS: OP862873; LSU: OP862873) were 99%-100% similar to H. mycophilus CBS 175.56 (ITS: MH857567; LSU: MH869110). Fifteen healthy fruiting bodies of A. cornea were inoculated by spraying spore suspension (106 conidia/mL) of the three isolates and five healthy fruiting bodies were sprayed with sterile water as control. All inoculated fruiting bodies were kept at 25 ℃. After three days, fruiting bodies of A. cornea treated with the spore suspension exhibited the same symptoms of cobweb as in the factory, while no symptom appeared in the control. Pathogens re-isolated from diseased fruiting bodies were confirmed to be H. mycophilus based on morphological characteristics, which fulfills the Koch's postulate. Zeng et al. (2017) reported H. mycophilus on the fruiting bodies of Auricularia sp. as a new record in Guangdong, China. H. mycophilus caused cobweb disease on A. auricula (Liu et al., 2020), A. cornea var. Li. (Cao et al., 2023) and A. heimuer (Zhang et al., 2023). To our knowledge, this is the first report of cobweb disease in A. cornea caused by H. mycophilus in Guizhou, China. Our findings will provide a basis for correct diagnosis and management of cobweb diseases on A. cornea.

Spider Fungi: New species of Marasmius and Pusillomyces in the aerial rhizomorph webmaker guild in Amazonia

Rhizomorphs are hair- or wire-like melanized structures with structural differentiation analogous to plant roots that help fungi spread over an area and find food resources. Some species of multiple groups of the Ascomycota and the Basidiomycota produce different types of rhizomorphs. In the Agaricales, the structures are largely found in Marasmiineae, particularly in the Omphalotaceae, Marasmiaceae, and Physalacriaceae. Many rhizomorph-forming species spread over the forest floor (ground level), while others form aerial litter-trapping rhizomorph systems that hang on living branches of the forest understorey. Here, we describe three new species that form aerial systems, two in Marasmius and one in Pusillomyces, all of which inhabit areas of the Amazon rainforest in Amazonas State, Brazil. Support for these new species is based on evidence derived from morphological and molecular phylogenetic analyses using nuclear ribosomal internal transcribed spacer region (nrITS) and nuclear ribosomal large subunit (nrLSU) markers. Marasmius foliauceps sp. nov., with a pileipellis made up of Rotalis-type broom cells, is different from all other species described to date and branched along with species of the monophyletic Marasmius sect. Marasmius subsect. Marasmius, being conspecific with specimens from Guyana. Also different from all other described Marasmius species, Marasmius arachnotropus sp. nov. has a pileipellis mostly composed of Siccus-type but in transition to Rotalis-type broom cells and branched along with species of the Marasmius crinis-equi species complex. Pusillomyces cuieirasensis is morphologicallyvery similar to Pusillomyces manuripioides to which it is sister, but it has a non-umbonate pileus and smaller basidiospores. They all form aerial litter-trapping rhizomorph systems that mimic spider webs, particularly those hanging on the understorey. Whether made of mycelia or silk, such webs serve to capture food. The aerial rhizomorph-forming ‘spider fungi’ make up a guild with hidden species diversity in tropical systems.

Phylogenetic evidence suggests the non-validity of the Iberian land snail genus Tartessiberus and confirms its synonymy with Iberus (Helicidae).

The monospecific genus Tartessiberus was described in the year 2021 including a single species (T.cilbanus). However, its description relied solely on morphological and anatomical data. In the present work, we use a fraction of the mitochondrial DNA cytochrome oxidase subunit I (COI), 16S ribosomal RNA (16S rRNA) and the nuclear large ribosomal subunit (LSU) to clarify its validity through phylogenetic positioning. Knowledge of the distribution of this species is also improved by citing new locations and expanding the geographical range to approximately 200 km2. Additionally, a morphometric analysis of 259 shells is presented for comparisons with shells of the Iberusmarmoratus complex and testing the power of conchological features as a tool for specimen identification. The relatively high conchological variability found for T.cilbanus, together with the discovery of populations with intermediate conchological features between T.cilbanus and other closely related taxa, suggest that the determination of this species should be based on genetic criteria. Our molecular analyses demonstrate that T.cilbanus belongs to the Iberus genus, and thus, we proceed to update its taxonomic status to Iberuscilbanuscomb. nov., and, thus, to consider Tartessiberus from now on as a junior synonym of Iberus.