Rosa roxburghii Tratt is a rosaceous shrub originating from southwest China (Fu et al. 2020). From September to October 2022, R. roxburghii rot occurred in Guizhou Province, China, within a major R. roxburghii production area covering from 5 ha to 50 ha, with an incidence rate of 10 to 15%. Symptoms manifested as black and brown lesions on the fruit surface, which were concave, soft, foul-smelling, and surrounded by grayish-brown tissue. Three infected R. roxburghii shrubs were randomly collected from each household, placed in transparent plastic bags, and pathogen isolation was conducted in a laboratory. Infected R. roxburghii fruits were surface-sterilized with 0.5% NaOCl for 2 min, rinsed five times with sterile water, and dried. Symptomatic tissues from the margin between necrotic and healthy tissues were cut into 5 × 5 mm pieces, placed onto potato dextrose agar (PDA), and incubated at 28ºC in the dark for 5 days. Hyphal tips of fungi growing from the samples were transferred onto new PDA plates and incubated until they produced conidia. A total of five fungal isolates with similar morphological characteristics were obtained. The colony obtained by single-spore purification was light purple to dark purple with abundant aerial mycelium. Macroconidia were relatively slender with a curve and zero to three septate. Microconidia appeared obovoid to pyriform, with sizes of 5.2 to 17.2 × 2.1 to 3.3 μm (n = 50). The morphological characteristics were consistent with Fusarium annulatum (Yilmaz et al. 2021). Genomic DNA of two representative isolates (Zhaochanglin 1621 and 1622) was extracted using the DN14 cetyltrimethylammonium bromide rapid plant genome extraction kit (Aidlab Biotechnologies Co., Ltd, Beijing). The TEF1 and RPB2 gene were amplified by Polymerase Chain Reaction using primers EF1-983F/EF1-2218R (Rehner et al, 2005), bRPB2-6F/bRPB2-7.1R (Matheny et al, 2002), respectively. All sequences were deposited in GenBank (TEF1, PP236860, PP236861; RPB2, PP767864, PP767865). BLAST searches of the TEF1, and RPB2 sequences revealed the TEF1 sequences had 99.89% (937/938 bp) identity with F. annulatum isolate CBS 258.54; and the RPB2 sequences had 99.86% (737/738 bp) identity to isolate CBS 267.93. In the phylogenetic tree, the isolates (Zhaochanglin 1621 and 1622) clustered with the representative strains of F. annulatum. The morphology and multi-gene phylogenetic analysis indicated that is the isolates were F. annulatum. To complete Koch\'s postulates, five mature, healthy R. roxburghii fruits were surface disinfected with 1% NaClO solution for 1 min, rinsed with sterile water, and dried at 25℃ for 30 min. A conidial suspension (106 spores/ml) collected from two isolates (Zhaochanglin 1621 and 1622) was sprayed onto R. roxburghii fruits, and the control treatments were sprayed with sterile distilled water. All R. roxburghii fruits were incubated at 25 ºC with 80% relative humidity. The experiment had five replicates. After 7 days of incubation, all the inoculated fruits showed similar symptoms to those initially observed on the originally infected plants. The same pathogen was reisolated and identified by morphological character ization and molecular analysis, fulfilling Koch\'s postulates. Thus, the pathogen causing rot of R. roxburghii was determined to be F. annulatum (H. Zhang et al, 2024). To our knowledge, this is the first report of F. annulatum causing R. roxburghii rot disease in China. F.annulatum has a wide range of hosts and has been reported to infect a wide range of crops, fruits, and vegetables (Bacon and Nelson 1994). This study lays a foundation for further study and developing disease control methods and the improvement of the economic benefits of R. roxburghii.

Ramularia mali Videira & Crous is an emerging postharvest pathogen on apple (Malus × domestica Borkh.) in Italy and other apple producing countries (Prencipe et al. 2023). After 3 to 6 months of cold storage at 1 - 2 °C and low oxygen levels of 0.5 - 2 %, lenticels show black-brown speckled dry rot of 1 mm - 5 mm in diameter, without colonizing underlying tissue. The most affected cultivar (cv.) in South Tyrol (northern Italy) is Golden Delicious and postharvest losses due to characteristic lenticel spots range from 10 % to above 50 %. Four symptomatic fruits, originating from two orchards (Latsch/Laces and Bozen/Bolzano; South Tyrol, Italy), respectively, were sampled after cold storage (= ultra-low oxygen; 0.5 % O2 and 1 °C). After surface disinfection with 70 % EtOH for 1 min, sixteen explants from lenticel spots were cultivated on potato dextrose agar (PDA) at 25 °C. Two isolates, morphologically identified as Ramularia sp., were sequenced and showed high identities to R. mali type culture CBS 129581: 100 % and 99.31 % identity for ITS region (MH865432); 94.66 % and 91.41 % for TEF-1α (KJ504693); 97.22% and 97.40% for RpbII (KJ504649). Isolates were cultivated at 25 °C for 2 weeks and conidia were harvested with 3.0 mL 0.05 % Tween®20. Inoculation was performed in triplicate on 5-month cold stored fruits cv. Golden Delicious. After surface disinfection for 1 min with cotton swabs, which were immersed in 70 % EtOH, 10 µL spore suspension of each isolate (8.50 × 107 spores mL-1 in 0.05 % Tween®20) were injected horizontally beneath the epidermis with a syringe (Hamilton® model 710N). Also, a mixture of both isolates was used. Controls were carried out with 0.05 % Tween®20 only. Apples were stored either at 9 °C in the dark or at 1°C and 0.5 % oxygen for 4 months. First symptoms were observed for both spore concentrations after 2 weeks at 9 °C. The injection pathway changed to a brownish color, whereas the control did not show any change (Fig. 1). Final evaluation was carried out after 4 months, but the fruits did not show further symptom development. Fruits stored at 1°C for 5 months were simultaneously evaluated, confirming that the pathogen invaded the tissue surrounding the injection site, without penetrating deeper into the fruit flesh. (Fig. 2). Reisolation from artificially infected apples was successfully achieved, and sequence analysis was performed on the DNA extracts from the obtained isolates. Concatenated sequences of ITS (deposited to GenBank under the accession numbers: PP439643 -PP439647), TEF-1α (PP480231-PP480235), and RbpII (PP480226-PP480230) were subjected to multi-locus sequence analysis. References sequences of R. nyssicola CBS 127665, R. collo-cygni CBS 101181, R. vizellae CBS 115981, R. eucalypti CBS 120726, R. hydrangeae-macrophyllae CBS 122272, R. glennii CBS 129441 and R. mali CBS 129581 included and aligned by the CLUSTALW algorithm within the software Geneious® 11.1.5 (Biomatters Inc., New Zealand). Phylogeny was reconstructed with MEGAX (Version 10.2.6) (Kumar et al. 2018) based on the Maximum Likelihood (ML) algorithm (Fig. 3). Isolates from artificially infected fruit clustered with the R. mali type culture. Although Gianetti et al. (2012) and Lindner (2013), respectively, first described Ramularia sp. as a postharvest pathogen on apple, the present study demonstrated the reproduction of lenticel dry rot symptoms by R. mali.

BACKGROUND: Cobweb disease is a fungal disease that commonly affects the cultivation and production of edible mushrooms, leading to serious yield and economic losses. It is considered a major fungal disease in the realm of edible mushrooms. The symptoms of cobweb disease were found during the cultivation of Lyophyllum decastes. This study aimed to identify the causative pathogen of cobweb disease and evaluate effective fungicides, providing valuable insights for field control and management of L. decastes cobweb disease.
RESULTS: The causal agent of cobweb disease was isolated from samples infected and identified as Cladobotryum mycophilum based on morphological and cultural characteristics, as well as multi-locus phylogeny analysis (ITS, RPB1, RPB2, and TEF1-α). Pathogenicity tests further confirmed C. mycophilum as the responsible pathogen for this condition. Among the selected fungicides, Prochloraz-manganese chloride complex, Trifloxystrobin, tebuconazole, and Difenoconazole exhibited significant inhibitory effects on the pathogen\'s mycelium, with EC50 values of 0.076 µg/mL, 0.173 µg/mL, and 0.364 µg/mL, respectively. These fungicides can serve as references for future field control of cobweb disease in L. decastes.
CONCLUSIONS: This study is the first report of C. mycophilum as the causing agent of cobweb disease in L. decastes in China. Notably, Prochloraz-manganese chloride complex demonstrated the strongest inhibitory efficacy against C. mycophilum.

The germ theory states that pathogenic microorganisms are responsible for causing infectious diseases. The theory is inherently microbe-centric and does not account for variability in disease severity among individuals and asymptomatic carriership-two phenomena indicating an important role for host variability in infection outcome. The basic tenet of the germ theory was recently challenged, and a radically host-centric paradigm referred to as the \"full-blown host theory\" was proposed. According to this view, the pathogen is reduced to a passive environmental trigger, and the development of disease is instead due to pre-existing immunodeficiencies of the host. Here, we consider the factors that determine disease severity using established knowledge concerning evolutionary biology, microbial pathogenesis, and host-pathogen interactions. We note that the available data support a noncentric view that recognizes key roles for both the causative microbe and the host in dictating infection outcome.

Leaf-blight disease caused by the Fusarium oxysporum is an emerging problem in Dendrobium chrysotoxum production in China. Symptoms of leaf blight were observed on seedlings of D. chrysotoxum cultivated in a nursery in Ruili City, Yunnan Province, China. In this study, we isolated the Fusarium sp. associated with leaf-blight disease of D. chrysotoxum from the diseased seedlings. A pathogenicity test was performed to fulfill Koch\'s postulates to confirm the pathogenicity of isolated strains and identified using morphological and molecular techniques. The results revealed that all four isolated Fusarium sp. isolates (DHRL-01~04) produced typical blight symptoms followed by marginal necrosis of leaves on the D. chrysotoxum plants. On the PDA medium, the fungal colony appeared as a white to purplish color with cottony mycelium growth. Microconidia are oval-shaped, whereas macroconidia are sickle-shaped, tapering at both ends with 2-4 septations. The phylogenetic trees were construed based on internal transcribed spacer (ITS), translation elongation factor (EF-1α), and RNA polymerase subunit genes RPB1 and RPB2 genes, respectively, and blasted against the NCBI database for species confirmation. Based on the NCBI database\'s blast results, the isolates showed that more than 99% identify with Fusarium oxysporum. To our knowledge, this is the first comprehensive report on the identification of Fusarium oxysporum as the causal agent of Dendrobium chrysotoxum leaf blight in Yunnan Province, China, based on morphological and molecular characteristics.

In 2015 and 2016, two Barramundi (Lates calcarifer) farms in Singapore reported a disease outbreak characterized by lethargic behavior, pronounced inappetence, generalized skin lesions, erosions of the fins and tail, and ultimately high mortality in their fish. Next-generation sequencing and PCR confirmed presence of a novel virus belonging to the Alloherpesviridae family, Lates calcarifer herpesvirus (LCHV), which was subsequently isolated and cultured. We characterize, for the first time, the complete genome of two cultured LCHV isolates. The genome contains a long unique region of approximately 105,000 bp flanked by terminal repeats of approximately 24,800 bp, of which the first 8.2 kb do not show any similarity to described genomes in the Alloherpesviridae family. The two cultured isolates share 89% nucleotide identity, and their closest relatives are the viruses belonging to the genus Ictalurivirus. Experimental infections using one of the cultured LCHV isolates resulted in identical clinical signs as originally described in the index farm, both in intraperitoneal-injection infected fish and cohabitant fish, with mortality in both groups. Histopathological analysis showed pronounced abnormalities in the gills. Virus culture and PCR analysis confirmed the replication of LCHV in the infected fish, and thus Koch\'s postulates were fulfilled.

UNASSIGNED: Leaf spot disease severely impacts Ginkgo biloba (G. biloba) yield and quality. While microbial agents offer effective and non-toxic biological control for plant diseases, research on controlling leaf spot disease in G. biloba is notably scarce.
UNASSIGNED: The pathogenic fungi were isolated and purified from diseased and healthy leaves of G. biloba, Subsequent examinations included morphological observations and molecular identification via PCR techniques. A phylogenetic tree was constructed to facilitate the analysis of these pathogenic fungi, and Koch\'s postulates were subsequently employed to reaffirm their pathogenic nature. The antagonistic experiment was employed to select biocontrol bacteria, and subsequently, the isolated biocontrol bacteria and pathogenic fungi were inoculated onto healthy leaves to assess the inhibitory effects of the biocontrol bacteria.
UNASSIGNED: Two pathologies responsible for the leaf spot disease on G. biloba were identified as Botryosphaeria dothidea and Neofusicoccum parvum via the analysis of phylogenetic tree and the application of Koch\'s Postulates. Additionally, we isolated two strains of biocontrol bacteria, namely Bacillus velezensis and Bacillus amyloliquefaciens. Their average inhibitory zones were measured at 4.78 cm and 3.46 cm, respectively. The inhibition zone of B. velezensis against N. parvum was 4 cm. B. velezensis showed a stronger inhibitory effect compared to B. amyloliquefaciens on the development of lesions caused by B. dothidea via leaf culture experiment.
UNASSIGNED: This research reports, for the first time, the presence of B. dothidea as a pathogenic fungus affecting G. biloba. Moreover, the biocontrol bacteria, B. velezensis and B. amyloliquefaciens, exhibited the capability to effectively inhibit the growth and reproduction of B. dothidea, indicating their promising potential as environmentally friendly biocontrol resources.

Tea (Camellia sinensis (L.) Kuntze) is one of the most important economic plants in China, and has many benefits for human health. Anthracnose is one of the most serious diseases of tea in China, and control of the fungus is important since most Chinese cultivars are susceptible to it. The agent of tea anthracnose was initially described as Gloeosporium theae-sinensis I. Miyake in Japan, which was later transferred to Discula, but this taxonomic position remains problematic. To shed light on these taxonomic and phylogenetic issues, the tea anthracnose pathogens were re-studied. Combining the morphological characteristics and a multigene phylogenetic analysis of nrITS, nrLSU, rpb2, and tef1 sequence data, a new genus Sinodiscula was proposed to accommodate the causal fungi of tea anthracnose, including a new species Sinodiscula camellicola and a new combination Sinodiscula theae-sinensis. Furthermore, the pathogenicity of the pathogens was determined according to Koch\'s postulates. This study thoroughly resolves the long-standing taxonomic and phylogenetic problems of the tea anthracnose pathogens.

Auricularia cornea is an important edible mushroom crop in China but the occurrence of cobweb disease has cause significance economic loss in its production. The rate of disease occurrence is 16.65% all over the country. In the present study, a new pathogen Hypomyces cornea sp. nov. was found to cause the cobweb disease. In July 2021, three strains of fungal pathogen were isolated from infected fruiting bodies and identified as H. cornea based on morphological studies and molecular phylogenetic analysis of internal transcribed spacer (ITS) of nuclear ribosomal DNA, mitochondrial large subunit (LSU) of rRNA and the partial translation elongation factor 1-alpha genes. The representative isolates of the pathogenic Hypomyces species used to perform pathogenicity test with spore suspension that caused similar symptoms as those observed in the cultivated field, and same pathogens could be re-isolated, which fulfill Koch\'s postulates. The typical biological characterization was examined of the serious pathogen to determine its favorable growth conditions, including suitable temperature, pH, carbon, nitrogen sources and light conditions. The findings revealed an optimum temperature of 25 °C, pH of 6, and soluble starch and peptone as the preferred carbon and nitrogen sources, respectively. The hyphal growth inhibition method was used for primary in vitro screening test of seven common fungicides, and the most suitable fungicide is Prochloraz manganese chloride complex, the EC50 values of cobweb pathogen and mushrooms were 0.085 μg/mL and 2.452 μg/mL, respectively. The results of our research provide an evidence-based basis for the effective prevention and treatment of A. cornea cobweb disease.

Artemisia capillaris (Asteraceae) is an annual herb found in ˃10 provinces in China. It is cultivated on ˃670 ha, with annual production around 2,500 tons. Its shoot is used in traditional Chinese medicine (Liu et al. 2021). From April to May 2023, Sclerotinia rot symptoms were seen at the Institute of Medicinal Plant Development (40.04°N, 116.28°E), Beijing, China. Disease incidence was up to 10% in the field through investigation of 300 plants. Initial symptoms were irregular tan-brown lesions (0.5 to 5.0 mm) that expended to circumferential necrosis on the roots and basal stem, aerial mycelia and sclerotia were developed on them. The leaves and stem tips were withered and droopy in severe cases. Twelve symptomatic primary roots of 12 plants from two sites were cut into 5 × 5 mm pieces, surface sterilized with 75% ethanol for 30 s and 5% NaClO for 60 s, rinsed with distilled water for three times, dried with sterile filter paper, put on potato dextrose agar (PDA), and incubated at 25°C in the dark for 2 days. Two Sclerotinia-like isolates were obtained using the hyphaltip method. White aerial mycelia were sparse and appressed for isolate YC1-3 and dense for isolate YC1-7. After incubated at 25°C in the dark for 15 days, 10 to 25 sclerotia were developed near the colony margin. Sclerotia of isolate YC1-3 were 1.0 to 3.9 × 1.2 to 4.5 (mean 1.8 × 2.2) mm (n = 60), ovoid or arc-shaped. Sclerotia of isolate YC1-7 were 1.5 to 3.4 × 2.7 to 9.2 (mean 2.3 × 4.3) mm (n = 60), ovoid, dumbbell shaped or curved. The isolates were identified as Sclerotinia sclerotiorum based on morphology (Maas 1998). To further identify the pathogens, molecular identification was performed with isolates YC1-3 and YC1-7. DNA of the two isolates were extracted by the cetyltrimethylammonium bromide (CTAB) method. Polymerase chain reaction was performed with primers ITS1/ITS4 for the internal transcribed spacer (ITS) region (Choi et al. 2020; White et al. 1990) and primers G3PDHfor/G3PDHrev for the glyceraldehyde 3-phosphate dehydrogenase (G3PDH) gene (Garfinkel. 2021). BLAST search analysis revealed that the ITS sequence (GenBank OR229758 and OR229762) was ≥99% similar to S. sclerotiorum (MN099281, MZ379265, KX781301, etc.), and the G3PDH sequence (OR778388 and OR761975) was too (MZ493894, JQ036048, OQ790148, etc.). Phylogenetic trees were computed with ITS and G3PDH sequences using the Maximum Likelihood in MEGA 11. Nine two-month-old seedlings of A. capillaris were used to test pathogenicity. The epidermis layer of each primary root was slightly wounded (2 × 2 mm, 1 mm deep) using a sterile dissecting blade. Three plants were inoculated with mycelial plugs (5 mm in diameter) of YC1-3 and YC1-7 that cultured on PDA for 7 days. Control plants were inoculated with sterile PDA plugs. All seedlings were then incubated at 25oC and 90% relative humidity. After isolate YC1-7 inoculation 3 days and isolate YC1-3 inoculation 5 days, inoculated roots had symptoms like those in the field, controls had no symptoms. S. sclerotiorum was consistently re-isolated from diseased roots, fulfilling Koch\'s postulates. Diseases caused by S. sclerotiorum have been reported threatens several important economical crops (Marin and Peres 2020; Guan et al. 2022). To our knowledge, this is the first report of S. sclerotiorum causes Sclerotinia rot on A. capillaris. To avoid of significant economic losses, it is urgent to establish an effective disease-management strategy.