Multigene Analysis Research Articles

First Report of Kosakonia cowanii Causing Bacterial Blight on Amorphophallus konjac in China.

Amorphophallus konjac, commonly known as konjac, has significant economic and medicinal value, particularly in Asian countries (Gao et al. 2022). In July 2024, an outbreak of leaf blight was observed in a one-hectare field in Fuyuan (25.67°N; 104.25°E), Yunnan, China. The disease manifested as brown lesions starting at the leaf tips or edges, which rapidly darkened and expanded, leading to leaf necrosis. In severe cases, the disease affected the overall plant health, reducing corm yield and quality significantly. To isolate the causal agent, six diseased leaves from six plants were surface disinfected, and the junction region of healthy and diseased tissues was excised and homogenized in a 15-ml sterile centrifuge tube with 2 ml of sterile distilled water. The resulting bacterial suspension was serially diluted to 10-5 and 200 μl of the diluted sample was spread on LB agar plates. Three pure cultures (designated MY1, MY2, and MY3) were obtained through successive streaking. The isolated colonies were light yellow, convex, and nearly round in shape. Genomic DNA from the three pure isolates was extracted and used to amplify partial sequences of 16S ribosomal RNA (16S rRNA) with primers 27F/1492R (Brady et al. 2008), the beta-subunit of RNA polymerase (rpoB) using primers CM81-F/CM32b-R (Polz and Cavanaugh 1998), and the DNA gyrase subunit B (gyrB) with primers UP-1/UP-2r (Yamamoto and Harayama 1995). The sequences for 16S rRNA (accession nos. PQ288765-PQ288767), rpoB (PQ304887-PQ304889), and gyrB (PQ304884-PQ304886) were deposited in GenBank. Nucleotide BLAST analysis showed that the rpoB, gyrB and 16S rRNA sequences of isolate MY1 shared 99.36, 98.89 and 99.86% identity with those of K. cowanii strains (EU629168, CP107077 and OR121838), respectively. Furthermore, a multigene phylogenetic analysis revealed a strongly supported clade including strain MY1, MY2, MY3 and other K. cowanii isolates. To test pathogenicity, a greenhouse experiment was conducted using five four-month-old healthy A. konjac plants grown in pots. For each plant, three leaves were inoculated with a bacterial suspension of strain MY1 (108 CFU/ml) via leaf infiltration. Another set of three leaves were infiltrated with sterile water as controls. These plants were enclosed in plastic bags for 24 hours post-inoculation. Inoculated plants initially exhibited brown lesions with a yellow halo, which subsequently developed into dark symptoms within seven days. Control plants remained symptom-free. This experiment was repeated three times with consistent results. K. cowanii was reisolated from infected leaves and identified based on Sanger sequencing of 16S rRNA, thus fulfilling Koch's postulates. In recent years, K. cowanii has been confirmed to cause fruit blotch on Trichosanthis fructus (Chen et al. 2024), stalk rot in foxtail millet (Han et al. 2023), bacterial wilt on patchouli (Zhang et al. 2022), and bacterial blight on soybean (Krawczyk and Borodynko-Filas 2020). To our knowledge, this is the first report of K. cowanii causing leaf blight on A. konjac worldwide. This study identifies a previously unrecognized disease affecting konjac production. The identification of the causal agent provides essential information for the diagnosis and management of this disease.

First Report of heart rot disease on Pineapple Caused by Phytophthora nicotianae in Guangxi province, China.

Pineapple (Ananas comosus) is a perennial economically important tropical fruit in Guangxi Province, China. Between September to November 2022, the rot of heart leaves of pineapple was found on 6.7 hectares of pineapple, NaLang village Jiangxi Town, Jiangnan District, Nanning City and on 200 hectare Liutian Village, Wangmao Town, Bobai County, Yulin City. The disease incidence of the investigated 10500 plants was from 20% to 30%. The basal heart leaves near the soil surface showed symptoms of water-soaked lesions and soft rot. The infected heart leaves were easily pulled out. As the disease developed, 800 plants of the investigated diseased plants collapsed and died. The diseased leaves from each district were surface-disinfected for 3 min with 1.0% hypochlorite solution, then rinsed three times in sterile water, and plated to carrot agar medium (CA media) (Luo et al. 2012). Inoculated dishes were incubated at 28°C in the dark. After 5 days, Eight mycelium colonies were recovered from diseased tissue. Colonies developing on CA exhibited white cottony mycelium which was aseptate. Numerous sporangia and chlamydospores were visible after 10-15 d later. The chlamydospores were spherical in shape and measured an average of 25.8 to 37.5 μm. The shape of the sporangia was papillate, oval or spherical, and 34.5 to 58.2 μm. These characteristics were consistent with the description of Phytophthora (Stamps et al. 1990). For molecular identification, the direct colony PCR method (Lu et al. 2012) was used to amplify the ITS of rDNA, β-tubulin (Tu), and elongation factor (EF) locus of the 2 strains NNPN1 from Nanning city and YLPN1 from Yulin city using the primer pairs of ITS4/ITS5, T1/T2 (O'Donnell et al. 1997) and EF1/EF2 (O'Donnell et al. 1998). The resulting sequences were deposited in GenBank (OR612028 and OR612029 for ITS; OR620158 and OR620159 for elongation factor; OR620160 and OR620161 for β-tubulin). BLAST searches with the three gene sequences revealed the greatest similarity with the sequences of some Phytophthora sp. The complete genome sequences of highly similar Phytophthora sp. were downloaded and the sequences of the corresponding 3 genes of each genome was extracted by Bioedit software. Phylogenetic trees were constructed in MEGA 11 using the maximum likelihood (ML) method based on the concatenated sequences of ITS, EF1α, and Tubulin (Figure 1). The 2 isolates grouped with P. nicotianae in the phylogenetic tree. The morphology and multi-gene phylogenetic analysis indicated that the new isolate was P. nicotianae. Tests of pathogenicity were performed according to Koch's postulates using the P. nicotianae strains NNPN1 and YLPN1. Fresh wounds were made symmetrically with a sterile needle on 2 tender basal leaves of pineapple plants (Bali variety) at the 8- to 10-leaf stage and each wound was covered with a piece of mycelium disc from each isolate. Control seedlings were inoculated identically except CA medium disc was used to cover the wound. Plants were placed in pots in a greenhouse at 28°C and 90% relative humidity. After 12 days, soft rot was observed clearly on the base of heart leaves of 9 inoculated plants, while the 9 control plants appeared normal. The pathogenicity tests were conducted three times with similar results. The strains were then reisolated from the infected plants and found to be Phytophthora sp. as those of the inoculum by morphology. P. nicotianae was previously reported as the causal agent of heart rot of pineapple in Guangdong and Hainan Province of China (Luo et al. 2012; Shen et al. 2013). To our knowledge, this is the first report of P. nicotianae on pineapple in Guangxi province in China. Identification of the pathogen of heart rot disease on pineapple is vital to reduce yield losses of the disease using effective control method.

Identification and biological characteristics of Fusarium tobaccum sp. nov., a novel species causing tobacco root rot in Jilin Province, China.

Fusarium wilt of tobacco (FWT), caused by Fusarium spp., has emerged as a severe threat to tobacco production in China. In all, 132 isolates of Fusarium were isolated from tobacco and pathogenic to tobacco-causing FWT in Jilin Province, China. In this study, we identified 7 of 132 isolates as a novel species Fusarium tobaccum sp. nov. Zhao Xie & Jie Gao, using multi-gene phylogenetic analyses of translation elongation factor (tef1), β-tubulin (tub2), calmodulin (cmdA), and RNA polymerase II second largest subunit (rpb2) genes, along with subtle morphological differences. Isolates of F. tobaccum sp. nov. were clustered in a distinct branch in the maximum parsimony phylogenetic tree generated from the sequences of tef1-rpb2-tub2-cmdA and can be distinguished from closely related species F. cugenangense, F. callistephi, and F. elaeidis. The morphological characteristics of F. tobaccum sp. nov. are distinct from other Fusarium species. F. tobaccum sp. nov. exhibits abundant aerial mycelia and pigment production on potato dextrose agar (PDA), microconidia with 0-1 septa, and macroconidia with 2-5 septa on carnation leaf-piece agar (CLA), and produces abundant chlamydospores on Spezieller Nährstoffarmer agar (SNA) and CLA. The mycelia of F. tobaccum exhibited optimal growth at a pH of 7.1 and a temperature of 23.6°C. Sucrose and NaNO3 significantly promoted the mycelial growth of F. tobaccum. PD medium was optimal for total sporulation. However, the sporulation ratios of the macrospores of F. tobaccum in PD, SN, and CMC were relatively low (0.48%, 2.51%, and 2.16%, respectively). These findings provided valuable insights into the morphological and biological characteristics of F. tobaccum.IMPORTANCEFusarium wilt of tobacco (FWT) is a prevalent issue in tobacco-growing regions globally, leading to significant losses in yield and quality. This study identified F. tobaccum sp. nov., a novel species of Fusarium causing FWT in China. The identification was based on multi-gene phylogenetic analyses and morphological characteristics. The effects of temperature, pH, carbon source, nitrogen source, medium, and light on the mycelial growth of F. tobaccum sp. nov. were determined. These findings might contribute to future research on the pathogenic mechanisms of this novel species and the development of strategies to control FWT.

Koima, a new genus of nemacheilid loach from the Western Ghats, India (Cypriniformes: Nemacheilidae)

Koima, a new genus of nemacheilid loach, is described for Mesonoemacheilus remadevii Shaji 2002, and Nemacheilus monilis Hora 1921, both of which are endemic to the Western Ghats of southern peninsular India. Koima is distinguished from all other genera of family Nemacheilidae by its unique colour pattern comprising a yellowish-brown ground colour, single row of black spots on lateral line, all fins hyaline, and absence of a uniform banding pattern on dorsal side. Koima remadevii was initially identified as a species of Mesonoemacheilus Bănărescu & Nalbant 1982, from which it can be distinguished by the presence of a lower adipose crest, and an absence of a banding pattern on the dorsal side and on the caudal fin, while Koima monilis was initially identified as a species of Nemacheilus Bleeker 1863, from which it can be distinguished by the presence of a lower adipose crest, a narrow and deeply incised upper lip and having the fins hyaline. In the multi-gene phylogenetic analysis based on concatenated mitochondrial and nuclear gene sequences, Koima remadevii and K. monilis were recovered in a monophyletic group, sister to the endemic peninsular Indian nemacheilid, Schistura denisoni. Resolution of the identity of Koima remadevii and K. monilis contributes to our understanding of the phylogenetics of family Nemacheilidae, which is widely considered to be a polyphyletic group.

Three New Species and Five New Host Records from Chaetomiaceae with Anti-Phytopathogenic Potential from Cover Crops Astragalus sinicus and Vicia villosa.

Cover crops, typically planted during off-seasons and requiring less agronomic manipulation, may provide abundant fungal resources. Certain species of Chaetomiaceae could serve as potential agents for controlling plant diseases and developing bioorganic fertilizers. Eight species from five genera of Chaetomiaceae were identified from healthy Astragalus sinicus and Vicia villosa, two major cover crops, through multigene phylogenetic analysis, morphological identification, and pairwise homoplasy index testing. The identified species comprise three new species: Achaetomium astragali, Subramaniula henanensis, and S. sichuanensis, as well as five known but new host record species: Botryotrichum murorum, Chaetomium coarctatum, C. pseudocochliodes, C. pseudoglobosum, and Collariella pachypodioides. Dual culture tests revealed that isolates of all eight Chaetomiaceae species exhibited antagonistic effects on multiple phytopathogens. Among the identified fungi, the NSJA2 isolate, belonging to C. coarctatum, exhibited significant relative inhibition effects on 14 out of 15 phytopathogens tested in this study, indicating its broad-spectrum antagonistic effects. Additionally, NSJA2 exhibited excellent salt tolerance. Overall, our study has identified multiple fungi with anti-phytopathogens potential, among which NSJA2 exhibits high potential for practical application. This finding paves the way for further exploration and exploitation of NSJA2 as a promising biocontrol agent.

Amphisphaeria hongheensis sp. nov. (Amphisphaeriaceae, Amphisphaeriales) from Yunnan Province, China

Yunnan Province encompasses the highest fungal diversity in China, and novel fungal species are regularly introduced. Several saprobic fungi were collected during surveys of fungi associated with woody plants in Yunnan Province, Southwestern China. The fungi samples were initially identified as Amphisphaeria. Multi-gene phylogenetic analysis based on combined datasets of LSU, ITS, rpb2, and tub2 regions and morphological characteristics confirmed that the samples represent a previously unidentified fungus belonging to Amphisphaeria, which is named A. hongheensis sp. nov. This paper provides a full description, illustrations, and a phylogenetic tree showing the new species' taxonomic placement.

Germline Variants in DNA Interstrand-Cross Link Repair Genes May Contribute to Increased Susceptibility for Serrated Polyposis Syndrome.

Serrated polyposis syndrome (SPS) is characterized by the development of multiple colorectal serrated polyps and increased predisposition to colorectal cancer (CRC). However, the molecular basis of SPS, especially in cases presenting family history of SPS and/or polyps and/or CRC in first-degree relatives (SPS-FHP/CRC), is still poorly understood. In a previous study, we proposed the existence of two molecular entities amongst SPS-FHP/CRC families, proximal/whole-colon and distal SPS-FHP/CRC, according to the preferential location of lesions and somatic events involved in tumor initiation. In the present study, we aimed to investigate these distinct subgroups of SPS patients in a larger cohort at the germline level and to identify the genetic defects underlying an inherited susceptibility for these two entities. Next-generation sequencing was performed using multigene analysis with a custom-designed panel in a Miseq platform in 60 SPS patients (with and without/unknown FHP/CRC). We found germline pathogenic variants in 6/60 patients (ATM, FANCM, MITF, RAD50, RAD51C, and RNF43). We also found variants of unknown significance (VUS), with prediction of probable damaging effect in 23/60 patients (ATM, BLM, BRCA1, FAN1, ERCC2, ERCC3, FANCA, FANCD2, FANCL, MSH2, MSH6, NTHL1, PALB2, PDGFRA, PMS2, PTCH1, RAD51C, RAD51D, RECQL4, TSC2, WRN, and XRCC5 genes). Most variants were detected in gene coding for proteins of the Fanconi Anemia (FA) pathway involved in the DNA Interstrand-Cross Link repair (ICLR). Notably, variants in ICLR genes were significantly more frequent in the proximal/whole-colon than in the distal subgroup [15/44 (34%) vs 1/16 (6%), p = 0.025], as opposed to the non-ICLR genes that were slightly more frequent in the distal group [8/44 (18%) vs. 5/16 (31%), p > 0.05]. Germline defects in the DNA-ICLR genes may contribute to increased serrated colorectal polyps/carcinoma risk in SPS patients, particularly in proximal/whole-colon SPS. The inclusion of DNA-ICLR genes in the genetic diagnosis of SPS patients, mainly in those with proximal/whole-colon lesions, should be considered and validated by other studies. In addition, patients with germline defects in the DNA-ICLR genes may be more sensitive to treatment with platinum-based therapeutics, which can have implications in the clinical management of these patients.

A rapid and parallel Late Pleistocene/Holocene morphological radiation in a predaceous planktonic water flea: the case of Bythotrephes (Cladocera: Cercopagididae)

Abstract The predatory cladoceran Bythotrephes is one of North America’s most successful and impactive invasive species in freshwater plankton communities. The taxonomic status of the genus Bythotrephes Leydig, 1860 (Crustacea: Cladocera: Cercopagididae) has remained unclear and a subject of intensive debate for over 150 years. We applied an integrative taxonomy approach with multi-gene analysis (mitochondrial COI and 12S genes, and nuclear 18S and 28S genes) on 80 individuals (representing at least four morphospecies) from various regions spanning the genus distribution (North America, Europe, and Asia) to resolve the taxonomic status of species within Bythotrephes. The results of our study strongly support the hypothesis of a single species—Bythotrephes longimanus Leydig, 1860, and ecological morphs should be accepted as junior synonyms. Our work also elucidates the very recent radiation of Bythotrephes, which may have begun rapidly and parallel during the Late Pleistocene, or even after the last glaciation. Finally, we provide a comprehensive biogeographic reconstruction of Bythotrephes dispersal within the Holarctic realm. Europe likely served as a dispersal centre for Bythotrephes from where they spread relatively recently (possibly, less than 10 kyr) and we distinguish five possible dispersal events in its evolutionary history.

Additions to the genus Kirschsteiniothelia (Dothideomycetes); Three novel species and a new host record, based on morphology and phylogeny.

During a survey of microfungi associated with forest plants, four specimens related to Kirschsteiniothelia were collected from decaying wood in Guizhou, Hainan and Yunnan Provinces, China. Kirschsteiniothelia species have sexual and asexual forms. They are commonly found as saprophytes on decaying wood and have been reported as disease-causing pathogens in humans as well. In this study, we introduce three novel Kirschsteiniothelia species (K.bulbosapicalis, K.dendryphioides and K.longirostrata) and describe a new host record for K.atra, based on morphology and multi-gene phylogenetic analyses of a concatenated ITS, LSU and SSU rDNA sequence data. These taxa produced a dendryphiopsis- or sporidesmium-like asexual morph and detailed descriptions and micromorphological illustrations are provided. Furthermore, we provide a checklist for the accepted Kirschsteiniothelia species, including detailed host information, habitat preferences, molecular data, existing morphological type, country of origin and corresponding references.

Catalogue of fungi in China 2. Ramaria from northern China

ABSTRACT The species of Ramaria are coralloid-fungi with intricately branched and vividly coloured basidiomata. There are many studies on the genus Ramaria in China, but molecular phylogenetic analysis is rarely employed. In this study, we performed a multigene phylogenetic analysis to identify Ramaria species in Shanxi Province of northern China. Phylogenetic analyses based on four loci, the internal transcribed spacer region of nuclear ribosomal DNA (ITS), the nuclear large subunit ribosomal DNA (nrLSU), ATPase subunit 6 (atp6), and mitochondrial small subunit ribosomal DNA (mtSSU), revealed 13 Ramaria species from our collections. Combined with morphological examinations, 12 of them were identified as new species, plus a new report to China. The thirteen species were described and illustrated in this paper.

Redefining phylogenetic placements of Hyphodiscosia: integrative taxonomic insights based on morphological and phylogenetic analyses

In conducting a survey on the diversity of lignicolous freshwater fungi across a north-south latitudinal gradient in the Asian region, two strains were collected from freshwater habitats. This species is characterized by forming pinkish sporulating colonies both on wood and in culture, presenting macronematous conidiophores that swollen at the apex, producing cylindrical, pink in mass, 1-septate conidia, each with two flexuous, filamentous appendages arising from the middle of the cells. These characteristics closely match the definition of Hyphodiscosia. Through multigene phylogenetic analysis, this study for the first time determines the phylogenetic position of Hyphodiscosia within Muyocopronaceae (Muyocopronales). This study provides detailed illustrations, updates on molecular data, and a morphological comparison with related genera within Muyocopronaceae, as well as discusses the validity of the currently accepted four species within Hyphodiscosia.

Trichoderma thailandense sp. nov. (Hypocreales, Hypocreaceae), a new species from Thailand

A new species of microfungus, described herein as Trichoderma thailandense was isolated from the pileus surface of oyster mushroom and upland black rice samples in Thailand. This species is described using morphological characteristics and molecular multi-gene analyses. Based on multi-gene phylogenetic analyses of the internal transcribed spacer (ITS) region of the rDNA, RNA polymerase subunit II gene sequences (rpb2), and translation elongation factor 1-α (tef1-α) gene revealed that the position of T. thailandense is well-supported within Harzianum clade of the genus Trichoderma, but distinct from other all other known species. A full description, illustrations and a phylogenetic tree showing the position of T. thailandense are provided.

New Occurrence of Nigrospora oryzae Causing Leaf Blight in Ginkgo biloba in China and Biocontrol Screening of Endophytic Bacteria.

Ginkgo biloba is a multifunctional composite tree species that has important ornamental, economic, medicinal, and scientific research value. In October 2023, the foliage of G. biloba on the campus of Nanjing Forestry University exhibited leaf blight. Black-brown necrotic spots were observed on a large number of leaves, with a disease incidence of 86%. After isolating a fungus from symptomatic leaves, pathogenicity was tested to satisfy Koch's postulates. Using morphological features and multi-gene phylogenetic analyses of an internal transcribed spacer (ITS), elongation factor 1-alpha (EF1-α), and beta-tubulin (β-tub), the isolates YKB1-1 and YKB1-2 were identified as Nigrospora oryzae. N. oryzae was previously reported as an endophyte of G. biloba. However, this study shows it to be pathogenic to G. biloba, causing leaf spots. Two endophytic bacteria were isolated from asymptomatic leaves of diseased G. biloba trees, and their molecular identification was performed using 16S ribosomal DNA (16S rDNA). GBB1-2 was identified as Bacillus altitudinis, while GBB1-5 was identified as Bacillus amyloliquefaciens. The screening and verification of endophytic bacteria provide a new strategy for the control of N. oryzae.

First Report of Alternaria alternata Causing Leaf Spot of Magnolia delavayi in China

Magnolia delavayi, known as Delavay's magnolia or Chinese evergreen magnolia, is an enchanting deciduous tree native to southwestern China (Xu et al. 2020). In March 2024, leaf spots were observed on M. delavayi plants at Qujing Normal University (25.527°N, 103.744°E), Qujing, Yunnan, China. About 80% of the trees (n=92) on campus were infected, with infected leaves accounting for about 10 to 30% of all leaves. The leaf spots exhibited a round or oval shape, with a yellowish-brown center and a brown outer ring. As the spots expanded, the leaves gradually dried up and fell off. Five symptomatic leaves were collected from the middle sections of five diseased plants. Tissue samples (5 × 5 mm) were excised from the lesion margins and subjected to surface sterilization in 75% ethanol for 30 seconds and 1% sodium hypochlorite for 60 seconds. They were then rinsed three times with sterile water and dried on sterilized paper. The samples were plated on potato dextrose agar (PDA) and incubated at 28 °C for 3 days. Developing colonies were retransferred to new PDA and purified by the hyphal tip technique (Senanayake et al. 2020). Two representative isolates (SYL1 and SYL2) were selected and confirmed to be the same species based on morphological characteristics and molecular identification. On PDA, the fungal colonies initially appeared grayish-white and turned dark gray over time with cotton-like aerial hyphae on the surface. The conidia are light brown, pear-shaped or rod-shaped, with 1 to 4 transverse septa and 0 to 1 oblique septa, and measured 5.4 to 12.7 × 10.4 to 25.7 μm (n = 50). Molecular identification was performed by partial sequencing of the internal transcribed spacer (ITS: ITS4/ITS5) region, glyceraldehyde 3-phosphate dehydrogenase (GAPDH:gpd1/gpd2), translation elongation factor 1-alpha (TEF1:EF1/EF2), and Alternaria major allergen (Alt a 1:Alt-for/Alt-rev) (Woudenberg et al. 2015). The resulting sequences of ITS (PP951882, PP951883), GAPDH (PP968942, PP968943), Alt a 1(PP968940, PP968941) and TEF1 (PP968938, PP968939) were deposited in GenBank. BLAST analyses revealed that the sequences from these two isolates showed 100% identity with those from Alternaria alternata strains for each gene. Additionally, a multigene phylogenetic analysis revealed a distinct group containing SYL1, SYL2 and other A. alternata strains with a posterior probability of 100%. The morphological and phylogenetic evidence collectively suggested that the two isolates belonged to A. alternata. Strain SYL1 was used for the pathogenicity test on three 5-year-old M. delavayi plants on campus. Three healthy leaves of each plant were punctured with a sterile needle and sprayed with 20 μl of spore suspension (1 × 106 conidia/ml). Similarly, another nine wounded leaves were sprayed with 20 μl of sterile water. All inoculated leaves were enclosed in plastic bags for 48 hours. Disease symptoms were observed on leaves inoculated with spore suspension after 7 days, while control plants remained healthy. This experiment was repeated three times with same results. To fulfill Koch’s postulates, A. alternata was reisolated from the inoculated leaves and identified based on morphological characteristics and ITS sequencing. To our knowledge, this is the first report of A. alternata causing leaf spot on M. delavayi in China. This research expands the known host range of this pathogen and provides relevant information to the design of disease management strategies.

Morpho-phylogenetic evidence reveals Pseudobionectria phoenicis gen. et sp. nov. (Bionectriaceae) from a mangrove habitat

A bionectriaceous ascomycete was collected from palm rachides in a mangrove habitat. Multi-gene phylogenetic analyses indicated this fungus belongs within the Bionectriaceae, forming a sister lineage to Septofusidium herbarum and distinct from other known genera. In this study, we proposed the new genus Pseudobionectria to accommodate the novel species P. phoenicis. Pseudobionectria is distinguished from other genera in Bionectriaceae by its superficial, globose, brownish-orange ascomata with a black crown that is flattened on the top and hyphal appendages that merge with the subiculum below. The asci are unitunicate, lacking a visible apical ring, and the ascospores are 1-septate, oblong-ellipsoidal to fusiform, hyaline, and exhibit spinose ornamentation. The establishment of this new genus is supported by morphological and phylogenetic evidence. Additionally, this paper provides a synopsis of the genera within Bionectriaceae, including information on the type species, morphological characteristics, lifestyles, molecular data and key publications.

Novel characterisation of Curvularia geniculata associated with leaf blight on Costus igneus in India

Costus igneus Nak, commonly referred as insulin plant or spiral flag, is a perennial herb belonging to the family Costaceae. Owing to its ability to regulate the blood sugar level, it is considered as a boon plant for diabetic patients, hence popularly known as the “sugar plant”. Although few foliar diseases have been documented on C. igneus, they generally occur in minor frequency under Indian conditions. However, in May 2022, a moderate to severe incidence of leaf blight was observed on insulin plants at University of Agricultural Sciences, GKVK, Bangalore, and nearby medicinal gardens. The affected leaves exhibited light brown lesions coalesced to form papery blight, gradually leading to complete drying of leaves. The current study aimed to identify, characterize, and document the fungal pathogen responsible for the disease, with a focus on its morphological, molecular, and biological characteristics to ensure accurate identification. Additionally, the study sought to determine optimal conditions for pathogen growth and sporulation to support the development of effective disease management strategies. The associated fungus was isolated, purified and identified as Curvularia geniculata through morphological and multigene phylogenetic analysis, using internal transcribed spacer (ITS) and large sub unit (LSU) regions of rDNA, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene. Biological characterization revealed that cornmeal agar (CMA) at 30 °C and pH of 7 were ideal for better growth and abundant sporulation. These findings, highlighting the emergence of C. geniculata as a novel fungal pathogen infecting C. igneus in India, are crucial for developing effective disease management strategies to safeguard the medicinal properties of the plant.

New Helminthosporium (Massarinaceae, Dothideomycetes) and Nigrospora (Incertae sedis, Sordariomycetes) species associated with walnut (Juglansregia L.) in China.

Six collections of ascomycetes were obtained from samples collected from dead branches and leaves of Juglansregia in Guizhou and Yunnan provinces, China. By incorporating multigene phylogenetic analysis (ITS, LSU, rpb2, SSU, tef1-α, tub2) supplemented by morphological data, we establish two novel species, namely Helminthosporiumguizhouense and Nigrosporayunnanensis. In morphology, H.guizhouense can be distinguished from H.caespitosum by its narrower conidia (13-16 µm vs. 27.3-35.5 µm), and N.yunnanensis is characterized by black, globose conidia (16.2 × 14.4 µm). The phylogenetic results further substantiated them as novel taxa. The present study contributes to our comprehension of the range of fungi found in Juglansregia, thereby expanding our knowledge of the diversity of fungi within this host.

Usefulness of multigene liquid biopsy of bile for identifying driver genes of biliary duct cancers.

Liquid biopsy (LB) is an essential tool for obtaining tumor-derived materials with minimum invasion. Bile has been shown to contain much higher free nucleic acid levels than blood plasma and can be collected through endoscopic procedures. Therefore, bile possesses high potential as a source of tumor derived cell-free DNA (cfDNA) for bile duct cancers. In this study, we show that a multigene panel for plasma LB can also be applied to bile cfDNA for comparing driver gene mutation detection in other sources (plasma and tumor tissues of the corresponding patients). We collected cfDNA samples from the bile of 24 biliary tract cancer cases. These included 17 cholangiocarcinomas, three ampullary carcinoma, two pancreatic cancers, one intraductal papillary mucinous carcinoma, and one insulinoma. Seventeen plasma samples were obtained from the corresponding patients before surgical resection and subjected to the LiquidPlex multigene panel LB system. We applied a machine learning approach to classify possible tumor-derived variants among the prefiltered variant calls by a LiquidPlex analytical package with high fidelity. Among the 17 cholangiocarcinomas, we could detect cancer driver mutations in the bile of 10 cases using the LiquidPlex system. Of the biliary tract cancer cases examined with this method, 13 (54%) and 4 (17%) resulted in positive cancer driver mutation detection in the bile and plasma cfDNAs, respectively. These results suggest that bile is a more reliable source for LB than plasma for multigene panel analyses of biliary tract cancers.

Multi-gene analysis of the Russula crown clade (Russulales, Basidiomycota) revealed six new species and Alboflavinae subsect. nov. from Fagaceae forests in China.

The crown clade is one of two major groups in the Russula subg. Russula. An analysis of Chinese samples was performed based on the morphology, internal transcribed spacer (ITS) sequences, and multi-gene phylogenies of 28S nrLSU, 16S mtSSU, rpb1, rpb2, and tef1-α. The results supported the independence of six new species: Russula alboflava (sect. Amethystinae), R. chrysantha (subsect. Chamaeleontinae), R. liyui (subsect. Laricinae), R. lutescens (subsect. Olivaceinae), R. paraxerampelina, and R. prunicolor (subsect. Xerampelinae) from Fagaceae forest habitats. Subsect. Alboflavinae was newly proposed in sect. Amethystinae. Members of the new subsection include R. alboflava, R. burlinghamiae, and possibly R. ballouii. Our analyses also supported the claim that two species of R. fulvograminea (subsect. Laricinae) and R. subrubens (subsect. Xerampelinae) have a Eurasian distribution. The habitat and primary hosts of the main phylogenetic clades within related subsections were summarized and discussed.

Foliar blight, leaf spot, and stem blackening diseases caused by Stemphylium beticola, Alternaria alternata, and Alternaria atra on dragon's head (Lallemantia iberica) in Iran

Dragon's head, Lallemantia iberica, is an oilseed crop adapted to be grown in cold-dry areas. In the growing season of 2022–23 a severe foliar blight, leaf spot, and stem blacking symptoms were observed in commercial fields in northern and northwestern Iran, leading to more than 50 % yield loss. Infected samples were collected and transferred to the laboratory. Following the isolation of fungal agents, five representative isolates were selected for further studies. Morphological studies, based on conidial shape, conidiation, and other mycological characteristics, were carried out on a pure culture established from a single spore. Furthermore, multigene phylogenetic analyses were performed using sequences of translation elongation factor 1-α (TEF1), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), RNA polymerase II second largest subunit (RPB2), and Internal Transcribed Spacer (ITS) rDNA genes for Alternaria isolates, along with calmodulin (cmdA) for the Stemphylium isolate. The morphological and molecular studies identified the fungal isolates as Alternaria atra, Alternaria alternata, and Stemphyliium beticola. Pathogenicity tests on the commercial cultivar ‘Sara’ indicated that all isolates were pathogenic to dragon's head, but they differed significantly in aggressiveness. To the best of our knowledge, this is the first report of the association of these fungal species with an important foliar disease on this crop in Iran and worldwide.