SDW served as a negative control, thus confirming its function. The treatments were kept in an incubator, maintained at 20 degrees Celsius and 80-85 percent relative humidity. Five caps and five tissues of young A. bisporus were used per repetition in the three-time experiment. The inoculated caps and tissues revealed brown blotches on all affected areas after 24 hours of inoculation. Within 48 hours, the inoculated caps darkened to a rich, dark brown shade, while the infected tissues underwent a color shift from brown to black, expanding across the entire tissue block and creating an extremely decayed appearance coupled with a foul odor. The clinical presentation of this disease closely resembled that of the original samples. No lesions were detected in the control group sample. Following the pathogenicity assessment, the pathogen was re-isolated from the contaminated tissues and caps, relying on morphological features, 16S rRNA gene sequences, and biochemical analyses, thereby satisfying Koch's postulates. Species within the Arthrobacter genus. The environment harbors a diverse and extensive population of these entities (Kim et al., 2008). Two prior studies have affirmed Arthrobacter spp. as the disease-inducing agent for edible fungal species (Bessette, 1984; Wang et al., 2019). The current report presents the novel observation of Ar. woluwensis inducing brown blotch disease in A. bisporus, indicating a previously unrecognized pathogenic interaction. Our results have the potential to contribute to the development of plant health and disease management strategies.
Cultivated as Polygonatum cyrtonema Hua, a variety of Polygonatum sibiricum Redoute, it is also a significant cash crop in China, as reported by Chen, J., et al. (2021). During the period from 2021 to 2022, a disease incidence of 30% to 45% was noted in Wanzhou District (30°38′1″N, 108°42′27″E) of Chongqing, where P. cyrtonema leaves exhibited symptoms resembling gray mold. Symptoms initially appeared between April and June, while a more than 39% leaf infection rate developed from July through September. The onset of symptoms was characterized by irregular brown spots, which subsequently progressed to the edges, tips, and stems of the leaves. bio-based economy In conditions marked by dryness, the afflicted tissue displayed a dehydrated, slim form, a light brown shade, and, during the later stages of the disease's progression, became dry and cracked. When relative humidity levels were elevated, infected foliage exhibited water-logged decay, featuring a brown band encircling the lesion, and a layer of grayish mold emerged. Eight visibly diseased leaves, representing typical cases, were collected to determine the causal agent. Leaf tissues were diced into 35 mm pieces, then surface sterilized for one minute in 70% ethanol and five minutes in 3% sodium hypochlorite solution. Thoroughly rinsed three times with sterile water, the samples were then inoculated onto potato dextrose agar (PDA) enriched with 50 g/ml streptomycin sulfate and incubated in complete darkness at 25°C for three days. Six colonies (3.5 to 4 cm in diameter) with matching morphological traits were then transferred to separate agar-containing plates. Early-stage growth of the isolates manifested in white, dense, and clustered hyphal colonies that expanded across the medium in every direction. Twenty-one days after initiation, the medium's lower layer displayed embedded sclerotia, changing color from brown to black, with dimensions fluctuating between 23 and 58 millimeters in diameter. Botrytis sp. was confirmed to be present in all six colonies. This JSON schema returns sentences, listed. Conidiophores bore conidia, which were grouped in grape-like clusters, each branch attached. The conidiophores' morphology was straight and their length was between 150 and 500 micrometers. The conidia, single-celled and elongated in an ellipsoidal or oval shape, were aseptate and had dimensions of 75 to 20 or 35 to 14 micrometers (n=50). For molecular identification, the DNA from representative strains 4-2 and 1-5 was extracted. The internal transcribed spacer (ITS) region was amplified with primers ITS1/ITS4; the RNA polymerase II second largest subunit (RPB2) sequences were amplified using RPB2for/RPB2rev; and the heat-shock protein 60 (HSP60) genes were amplified with primers HSP60for/HSP60rev, as described in White T.J., et al. (1990) and Staats, M., et al. (2005). The GenBank repository held the sequences from groups 4-2 (ITS, OM655229 RPB2, OM960678 HSP60, OM960679) and 1-5 (ITS, OQ160236 RPB2, OQ164790 HSP60, OQ164791). Vadimezan Based on phylogenetic analysis of multi-locus alignments, the 100% sequence similarity between isolates 4-2 and 1-5 and the B. deweyae CBS 134649/ MK-2013 ex-type (ITS: HG7995381, RPB2: HG7995181, HSP60: HG7995191) conclusively establishes strains 4-2 and 1-5 as belonging to the B. deweyae species. Koch's postulates, using Isolate 4-2, were implemented to confirm if B. deweyae is capable of inducing gray mold in P. cyrtonema, as described by Gradmann, C. (2014). A 10 mL solution of 55% glycerin containing hyphal tissue was applied to the leaves of P. cyrtonema that had been previously washed in sterile water, after being grown in pots. Ten milliliters of 55% glycerin was used as a control, applied to the leaves of a different plant, and Kochs' postulates were investigated three times in experimental trials. Under controlled environmental conditions, characterized by a relative humidity of 80% and a temperature of 20 degrees Celsius, the inoculated plants were maintained. On the seventh day after the inoculation process, leaves of the inoculated plants manifested disease symptoms strikingly similar to those seen in the field, whereas the control plants continued to exhibit no signs of the disease. The fungus, originating from inoculated plants and identified as B. deweyae, was successfully reisolated through multi-locus phylogenetic analysis. To the best of our knowledge, B. deweyae's primary habitat is on Hemerocallis plants, potentially being a key factor in the appearance of 'spring sickness' symptoms (Grant-Downton, R.T., et al. 2014). This marks the first report of B. deweyae causing gray mold on P. cyrtonema within China. Although B. deweyae's host selection is limited, it remains a possible danger to P. cyrtonema. This project will serve as a foundation for future approaches to preventing and treating this disease.
The pear tree (Pyrus L.) in China holds a prominent position in the global fruit industry due to its massive cultivation area and yield, as confirmed by Jia et al. (2021). Brown spot symptoms manifested on the 'Huanghua' pear variety (Pyrus pyrifolia Nakai) during the month of June 2022. Within Anhui Agricultural University's High Tech Agricultural Garden, situated in Hefei, Anhui, China, Huanghua leaves are part of the germplasm garden collection. The disease incidence among 300 leaves (50 leaves per plant, sampled from 6 plants) was approximately 40%. Initially, the leaves showed the emergence of small, brown, round to oval lesions, featuring gray centers encircled by brown to black borders. Characterized by rapid growth, these spots ultimately brought about abnormal leaf shedding. To isolate the brown spot pathogen, symptomatic leaves were collected, rinsed with sterile water, sanitized with 75% ethanol for 20 seconds, and then thoroughly rinsed multiple times with sterile water. Isolates were obtained by placing leaf fragments on PDA medium and incubating them at 25 degrees Celsius for a duration of seven days. Incubation for seven days resulted in the colonies' aerial mycelium exhibiting a coloration ranging from white to pale gray, culminating in a diameter of sixty-two millimeters. Phialides, characterized by their doliform or ampulliform shape, were identified as the conidiogenous cells. Conidia varied in shape and size, from subglobose to oval or obtuse, with thin walls, aseptate hyphae, and a smooth surface finish. The subjects' diameter was observed to fluctuate between 42 and 79 meters and 31 and 55 meters. The morphologies' likeness to Nothophoma quercina, as reported in Bai et al. (2016) and Kazerooni et al. (2021), is noteworthy. Primers ITS1/ITS4 for internal transcribed spacers (ITS), Bt2a/Bt2b for beta-tubulin (TUB2), and ACT-512F/ACT-783R for actin (ACT) regions, were used respectively for the amplification of these regions in the molecular analysis. GenBank's repository now includes the ITS, TUB2, and ACT sequences, identified by accession numbers OP554217, OP595395, and OP595396, respectively. stomach immunity A nucleotide blast search indicated a striking similarity between the sequences and those of N. quercina, with MH635156 (ITS 541/541, 100%), MW6720361 (TUB2 343/346, 99%), and FJ4269141 (ACT 242/262, 92%) showing particularly high homology. A phylogenetic tree, showcasing the highest similarity to N. quercina, was created from ITS, TUB2, and ACT sequences using MEGA-X software's neighbor-joining algorithm. To verify the pathogen's ability to cause disease, three healthy plants' leaves were sprayed with a spore suspension (106 conidia/mL), in contrast, control leaves were treated with sterile water. Inside a growth chamber, inoculated plants were grown at a temperature of 25°C and 90% relative humidity, enclosed within plastic sheeting. Within seven to ten days, the expected symptoms of the disease became noticeable on the inoculated leaves; this was not the case for the control leaves. Re-isolation of the same pathogen from the afflicted leaves confirmed Koch's postulates. Morphological and phylogenetic analyses of the disease-causing organism revealed *N. quercina* fungus as the culprit behind brown spot, supporting the findings of Chen et al. (2015) and Jiao et al. (2017). According to our information, this represents the inaugural documentation of brown spot disease, attributable to N. quercina, affecting 'Huanghua' pear leaves within China.
A delectable variety of tomato, cherry tomatoes (Lycopersicon esculentum var.), stand out for their vibrant color and small size. The cerasiforme tomato, a primary cultivar in Hainan Province, China, is renowned for its nutritional richness and delightful sweetness (Zheng et al., 2020). A leaf spot ailment was noted on cherry tomatoes (Qianxi variety) in the Chengmai region of Hainan Province, spanning the period between October 2020 and February 2021.