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Corticospinal neurons (CSNs) represent the direct cortical outputs to the spinal cord and play important roles in motor control across different species. However, their organizational principle remains unclear. By using a retrograde labeling system, we defined the requirement of CSNs in the execution of a skilled forelimb food-pellet retrieval task in mice. In vivo imaging of CSN activity during performance revealed the sequential activation of topographically ordered functional ensembles with moderate local mixing. Region-specific manipulations indicate that CSNs from caudal or rostral forelimb area control reaching or grasping, respectively, and both are required in the transitional pronation step. These region-specific CSNs terminate in different spinal levels and locations, therefore preferentially connecting with the premotor neurons of muscles engaged in different steps of the task. Together, our findings suggest that spatially defined groups of CSNs encode different movement modules, providing a logic for parallel-ordered corticospinal circuits to orchestrate multistep motor skills.
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Médula Cervical/fisiología , Destreza Motora , Vías Nerviosas , Animales , Calcio/análisis , Corteza Cerebral/citología , Corteza Cerebral/fisiología , Médula Cervical/citología , Miembro Anterior/fisiología , Articulaciones/fisiología , Ratones , Ratones Endogámicos C57BLRESUMEN
STUDY OBJECTIVE: To evaluate the efficacy and pregnancy outcomes of intrauterine balloon and intrauterine contraceptive devices in the prevention of adhesion reformation following hysteroscopic adhesiolysis in infertile women with moderate to severe intrauterine adhesion. DESIGN: A prospective, randomized, controlled trial study. SETTING: A tertiary university hospital. PATIENTS: A total of 130 patients with moderate (American Fertility Society [AFS] score of 5-8) and severe (AFS score of 9-12) intrauterine adhesions were recruited. INTERVENTIONS: 86 patients were evenly allocated to group treated with an IUD for 1 month and group treated with an IUD for 2 months. 44 patients were allocated to group treated with a Foley catheter balloon.(IUD: Yuangong IUD). MEASUREMENTS AND MAIN RESULTS: The primary outcome measures were the AFS score, endometrial thickness, and pregnancy outcome. After hysteroscopy, the AFS score was significantly decreased(P<0.05), whereas endometrial thickness was significantly increased across the three groups(P<0.001). Notably, the decline in the AFS score in the balloon group was greater than that in the IUD-1-month group and IUD-2-month group(P<0.01), with no significant difference between the IUD groups(P = 0.298). Lastly, In addition, the extent of the increase in endometrial thickness(P = 0.502) and the pregnancy outcomes(P = 0.803) in the three groups were not significantly different. CONCLUSION: Inserting a balloon or placing an IUD for one or two months can effectively lower the risk of adhesion recurrence and restore the shape of the uterine cavity. While the therapeutic effect of the balloon was superior to that of the IUD, no significant differences were observed in the one-month and two-month IUD groups. TRIAL REGISTRATION: This research was registered in the Chinese Clinical Trial Registry ( http://www.chictr.org.cn/enIndex.aspx ); Clinical trial registry identification number: ChiCTR-IOR-17,011,943 ( http://www.chictr.org.cn/showprojen.aspx?proj=17979 ). Date of trial registration: July 11, 2017.
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Histeroscopía , Infertilidad Femenina , Dispositivos Intrauterinos , Resultado del Embarazo , Humanos , Femenino , Adherencias Tisulares/prevención & control , Adulto , Embarazo , Histeroscopía/métodos , Infertilidad Femenina/terapia , Infertilidad Femenina/etiología , Infertilidad Femenina/prevención & control , Estudios Prospectivos , Enfermedades Uterinas/cirugía , Enfermedades Uterinas/complicaciones , Enfermedades Uterinas/prevención & control , Enfermedades Uterinas/patología , Resultado del Tratamiento , Índice de EmbarazoRESUMEN
BACKGROUND: Parkinson's disease (PD) is a common central nervous system neurodegenerative disease. Neuroinflammation is one of the significant neuropathological hallmarks. As a traditional Chinese medicine, Safranal exerts anti-inflammatory effects in various diseases, however, whether it plays a similar effect on PD is still unclear. The study was to investigate the effects and mechanism of Safranal on PD. METHODS: The PD mouse model was established by 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine MPTP firstly. Next, the degree of muscle stiffness, neuromuscular function, motor retardation and motor coordination ability were examined by observing and testing mouse movement behavior. Immunofluorescence staining was used to observe the expression of tyrosine hydroxylase (TH). The dopamine (DA) content of the striatum was detected by High-performance liquid chromatography (HPLC). The expression of TH and NLRP3 inflammasome-related markers NLRP3, IL-1ß, and Capase-1 were detected by Real-time Polymerase Chain Reaction (qRT-PCR) and western blotting (WB) respectively. RESULTS: Through behavioral testing, Parkinson's mouse showed a higher muscle stiffness and neuromuscular tension, a more motor retardation and activity disorders, together with a worse motor coordination compared with sham group. Simultaneously, DA content and TH expression in the striatum were decreased. However, after using Safranal treatment, the above pathological symptoms of Parkinson's mouse all improved compared with Safranal untreated group, the DA content and TH expression were also increased to varying degrees. Surprisingly, it observed a suppression of NLRP3 inflammation in the striatum of Parkinson's mouse. CONCLUSIONS: Safranal played a neuroprotective effect on the Parkinson's disease and its mechanism was related to the inhibition of NLRP3 inflammasome activation.
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Ciclohexenos , Modelos Animales de Enfermedad , Inflamasomas , Proteína con Dominio Pirina 3 de la Familia NLR , Fármacos Neuroprotectores , Enfermedad de Parkinson , Terpenos , Animales , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Ratones , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Terpenos/farmacología , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/metabolismo , Masculino , Ciclohexenos/farmacología , Inflamasomas/metabolismo , Inflamasomas/efectos de los fármacos , Ratones Endogámicos C57BL , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Dopamina/metabolismo , Cuerpo Estriado/metabolismo , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/patología , Interleucina-1beta/metabolismo , Tirosina 3-Monooxigenasa/metabolismo , 1-Metil-4-fenil-1,2,3,6-Tetrahidropiridina , Caspasa 1/metabolismoRESUMEN
OBJECTIVES: This study aims to gain insight into each attribute as presented in the value of implantable medical devices, quantify attributes' strength and their relative importance, and identify the determinants of stakeholders' preferences. METHODS: A mixed-methods design was used to identify attributes and levels reflecting stakeholders' preference toward the value of implantable medical devices. This design combined literature reviewing, expert's consultation, one-on-one interactions with stakeholders, and a pilot testing. Based on the design, six attributes and their levels were settled. Among 144 hypothetical profiles, 30 optimal choice sets were developed, and healthcare professionals (decision-makers, health technology assessment experts, hospital administrators, medical doctors) and patients as stakeholders in China were surveyed. A total of 134 respondents participated in the survey. Results were analyzed by mixed logit model and conditional logit model. RESULTS: The results of the mixed logit model showed that all the six attributes had a significant impact on respondents' choices on implantable medical devices. Respondents were willing to pay the highest for medical devices that provided improvements in clinical safety, followed by increased clinical effectiveness, technology for treating severe diseases, improved implement capacity, and innovative technology (without substitutes). CONCLUSIONS: The findings of DCE will improve the current evaluation on the value of implantable medical devices in China and provide decision-makers with the relative importance of the criteria in pricing and reimbursement decision-making of implantable medical devices.
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Prioridad del Paciente , Prótesis e Implantes , Humanos , Encuestas y Cuestionarios , Resultado del Tratamiento , China , Conducta de ElecciónRESUMEN
Rhododendron simsii (indoor azalea) is widely cultivated for its high ornamental value (Xu et al. 2021). In April to May 2023, a leaf spot disease occurred in a field study at the Baili Azalea Forest Area (27°12'N, 105°48'E), Guizhou Province, China. About 500 plants were investigated, and the results showed that the incidence of leaf spot was 20 ~ 30%. To study this disease, 10 plants showing severe symptoms were collected. Initially, the symptoms were round or irregularly shaped brown spots (1 to 10 mm). With time, the spots enlarged and merged. Symptomatic leaves were washed with sterile distilled water, and 5 × 5 mm pieces of the infected tissues were removed. After surface sterilization (30 s with 75% ethanol, 2 min with 3% NaOCl, then washed three times with sterilized distilled water), the leaf pieces were dried and placed on potato dextrose agar (PDA) and incubated at 25â for 5 days. Fungal colonies developed from leaf tissues, and the germinated spores were transferred onto PDA for further purification and morphological observation. Three isolates (GUBJ23, GUBJ24, and GUBJ12) with similar morphology were obtained from five affected leaves. The representative strain GUBJ23 was selected for further study. On PDA the mycelium was initially white but with sporulation turned gray and then black. Black, single-celled conidia, spherical to sub-spherical, from 11.80 to 21.39 × 13.38 to 21.83 µm (n = 50) in diameter were borne singly on hyaline vesicles at the tips of conidiophores. These morphological characteristics were similar to those of Nigrospora sphaerica (Wang et al. 2017). To confirm the identification, primer pairs for the internal transcribed spacer (ITS) region (ITS5/ITS4), ß-tubulin (TUB2) (Bt-2a/Bt-2b), and the translation elongation factor 1-alpha (TEF1-α) (EF1-728F/EF1-986R), were used for PCR amplification of DNA from strain GUBJ23 (Carbone and Kohn 1999; Glass et al. 1995; White et al. 1990). The resulting sequences were deposited in GenBank with accession numbers OR818025 (ITS), OR835150 (TUB2), and OR835147 (TEF1-α). BLAST searches of the sequences revealed 99.80% identity (503/504 bp) of the ITS sequence, 100.00% identity (395/395 bp) of the TUB2 sequence, and 100.00% identity of the TEF1-α sequence (241/241 bp) with N. sphaerica LC7294 (accessions KX985932, KY019602, and KY019397, respectively.) Based on a combined dataset of ITS, TEF1-α, and TUB2 sequences, a phylogenetic tree was constructed using the maximum likelihood method and confirmed that isolates GUBJ23, GUBJ24, and GUBJ12 were N. sphaerica (Wang et al. 2017). Leaves of three healthy R. simsii plants were spray-inoculated with a spore suspension (105 conidia/mL), and an additional three plants were sprayed with sterile water. These plants were incubated at 25â in 75% relative humidity. After 5 to 7 days of inoculation, 0.5 to 1.8 mm spots appeared on the leaves. At 10 to 14 days after inoculation, grayish brown, semicircular or irregular lesions appeared on the leaves, usually with a diameter of 0.8 to 3 mm. The symptoms were like symptoms seen on naturally infected leaves, while the control leaves remained asymptomatic. The pathogen was re-isolated from diseased leaves and identified by morphological characterization and molecular analyses (ITS, TUB and TEF1-α), and the reisolated pathogen was identical to N. sphaerica. Thus completing Koch's postulates. According to previous research, N. sphaerica is a widely distributed phytopathogenic fungus that has a wide host range (Wang et al. 2017). This study is the first to identify N. sphaerica as the cause of leaf spot disease in R. simsii. Given the popularity of R. simsii as a pot plant and landscape shrub in Asia and othr regions, the occurrence of leaf spot disease seriously affects its ornamental and economic value. Therefore, it is crucial to establish and implement effective disease management practices to reduce impact of the disease.
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Rhododendron latoucheae Franch. is an evergreen shrub with charming fragrance and large and abundant flowers that make it highly attractive as an ornamental species. The species is distribution in southwest China covers several different habitats and environments (Zhang, et al. 2022). From May to July in 2023, symptoms of leaf spot were observed on R. latoucheae over a wide portion of the Baili Azalea Forest Area (27°10' to 27°20'N, 105°04' to 106°04'E), Guizhou Province, China. About 500 plants were surveyed, and the incidence of leaf spot on R. latoucheae leaves was 12%, significantly reducing their ornamental and economic value. The affected leaves had irregular, grey white lesions with a clear blackish brown boundary and faint black conidiomata in a brown center. To isolate the pathogen, 15 symptomatic leaves were collected from 10 plants. A few black dots were picked from the lesions with a sterilized needle, plated on water agar, and incubated at 25°C for 24 h to observe spore germination (Choi et al. 1999). Then the germinated spores were transferred onto PDA for further purification and morphological observation. Three single-spore isolates (GULJ1-L7, GULJ1-L8, and GULJ1-L9) identical in morphology were obtained. The isolate GULJ 1-L7 was used for further study. Colonies on PDA irregular grew white felty aerial mycelium, becoming white felted aerial mycelium in the centre and grey-brown mycelium at the marginal area on the upper surface, while the lower surface presents alternating white, tan and taupe. Colony with conidiomata irregularly distributed over agar surface. In the representative isolate, darkly pigmented pycnidia (flask-shaped) were produced over the colony surface on PDA after about 30 days, and oozed milky or yellowish mucilaginous drops. The fungus produced two types of conidia, α and ß. Regular α conidia were 5.15-10.29 × 1.54-3.33 µm (n = 50), hyaline, elongated, biguttulate and non-septate. Beta conidia were 20.34-31.91 × 1.01-1.90 µm (n = 50), aseptate, hyaline, smooth, spindle shaped, slightly curved to bent. The morphological features were consistent with the description of Diaporthe eres (Pereira, et al. 2022). The pathogen was confirmed to be D. eres by amplification and sequencing of the internal transcribed spacer region (ITS), the partial ß-tubulin (TUB), the partial translation elongation factor 1-alpha (TEF) genes and the calmodulin (CAL) using primers ITS1/ITS4, Bt-2a/Bt-2b, EF1-728F/EF1-986R, and CAL-228F/CAL-737R, respectively (Tao et al. 2020). Sequences from PCR amplification were deposited in GenBank with accession numbers OR740563 (ITS), OR754301 (TUB), OR754298 (TEF), and OR754295 (CAL) respectively. BLAST searches of the sequences revealed 99.07% (533/538 nt), 100% (490/490 nt), 99.69% (317/318 nt) and 98.95% (376/380 nt) homology with those of D. eres AR5193T from GenBank (KJ210529.1, KJ420799.1, KJ210550.1 and KJ434999.1), respectively. Phylogenetic analysis (MEGA 7.0) using the maximum-likelihood method placed the isolate GULJ1-L7 in a well-supported cluster with D. eres CBS 138694T. The pathogen was thus identified as D. eres based on the morphological characterization and molecular analyses (Feng, et al. 2013; Tao, et al. 2020). The pathogenicity of GULJ1-L7 was tested through a pot assay. Due to the difficulty of artificial planting wild R. latoucheae, we conducted a pot essay to detect the pathogenicity of GULJ1-L7 using a closely related Rhododendron delavayi Franch. Ten healthy R. delavayi plants were scratched with a sterilized needle (0.45 mm in diameter) on three leaves per plant. Plants were inoculated by spraying α and ß spore mixture suspension (106 spores ml-1) of GULJ1-L7 onto leaves until runoff, and the control leaves were sprayed with sterile water. The plants were maintained at 25°C and 75% relative humidity in a growth chamber. The pathogenicity test was repeated three times. After 14 days, the treated leaves developed brown lesions similar to those in the field, whereas the control had no symptoms. The same fungus was reisolated from the infected leaves and identified based on a morphological characterization and molecular analyses. These results fulfilled Koch's postulates. To our knowledge, this is the first report of leaf spot on R. latoucheae caused by D. eres in China. The fungal pathogen identification will provide valuable information for prevention and management of leaf spot disease associated with R. latoucheae.
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Rosa roxburghii Tratt is a plant from the Rosaceae family whose fruits are rich in vitamins, dietary fiber, flavonoids, phenolic acids, and other active components (Jiang, et al. 2024). In July 2023, about R. roxburghii 500 plants were investigated in a field of 6000 m2 in Guiding County (107°14'E, 26°45'N), Guizhou province, China, and the results showed a leaf spot incidence of s 20 to 30%. . The affected leaves had irregular, black lesions with a clear blackish brown boundary and faint black conidiomata in a brown center. Fifteen symptomatic leaves were collected from 10 plants washed with sterile distilled water, and 5 × 5 mm pieces of the infected tissues were cut. After surface sterilization for30 s with 75% ethanol, 2 min with 3% NaOCl, three washes in sterilized distilled water, the leaf pieces were dried and placed on potato dextrose agar (PDA) and incubated at 25â for 5 days. Three isolates (H3-Y-1-1, H3-Y-1-2, H3-Y-1-3) with identical morphology were obtained, and the isolate H3-Y-1-1was selected for further study. The colonies on PDA exhibited irregular growth patterns, with white felty aerial mycelium on the upper surface, and white mycelium on the lower surface. Conidiomata were irregularly distributed over the agar surface. The isolate H3-Y-1-1 produced darkly pigmented pycnidia on PDA after 30 days and oozed milky mucilaginous drops. The fungus produced two types of conidia, α and ß. Regular α conidia were 4.74 - 5.96 × 1.52 - 2.24 µm (n = 50), hyaline, elongated, biguttulate and non-septate. Beta conidia were 20.13 - 25.74 × 0.86 - 1.29 µm (n = 50), aseptate, hyaline, smooth, spindle shaped, slightly curved to bent. The morphological features were consistent with the description of Diaporthe eres (Pereira, et al. 2022). The pathogen was confirmed to be D. eres by amplification and sequencing of the internal transcribed spacer region (ITS), the partial ß-tubulin (TUB), the partial translation elongation factor 1-alpha (TEF) genes using primers ITS1/ITS4, Bt-2a/Bt-2b, EF1-728F/EF1-986R, respectively. Sequences from PCR amplification were deposited in GenBank with accession numbers PP411998 (ITS), PP502153 (TUB), PP502156 (TEF). BLAST searches of the sequences revealed (96%) (500/523nt), 97% (479/494 nt) and 99% (334/338 nt) homology with those of D. eres CBS 138594 from GenBank (OM698848, OM752196 and OM752197), respectively. Phylogenetic analysis using maximum-likelihood and Bayesian methods placed the isolate H3-Y-1-1 in a well-supported cluster with D. eres CBS 101742. The pathogen was thus identified as D. eres based on the morphological characterization and molecular analyses (Feng, et al. 2013; Tao, et al. 2020). To assess its pathogenicity, healthy R. roxburghii potted plants were inoculated with H3-Y-1-1 spore suspensions. Symptomatic leaves mirroring field symptoms were observed after XX days of incubations at XX°C, while control plants exhibited no symptoms. Diaporthe eres was consistently reisolated from the infected leaves showing brown irregular or round lesions at the initial stage of the disease, expanding and become more irregular over time ultimately causing leaf curling and plant death. To our knowledge, this is the first report of leaf spot on R. roxburghii caused by D. eres in China. The disease may become a serious threat to fruit of R. roxburghii production in China. Therefore, detection of this pathogen is very important to ensure timely disease management.
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BACKGROUND: There are a large number of infertile couples in China, but its treatment is notoriously expensive and not currently covered by insurance. The utility of preimplantation genetic testing for aneuploidy as an adjunct to in vitro fertilization has been debated. OBJECTIVE: To investigate the cost-effectiveness of preimplantation genetic testing for aneuploidy (PGT-A) versus conventional technology in in vitro fertilization (IVF) from the perspective of the healthcare system in China. METHODS: Following the exact steps in the IVF protocol, a decision tree model was developed, based on the data from the CESE-PGS trial and using cost scenarios for IVF in China. The scenarios were compared for costs per patient and cost-effectiveness. One-way sensitivity analysis and probabilistic sensitivity analysis were performed to confirm the robustness of the findings. MAIN OUTCOME MEASURES: Costs per live birth, Costs per patient, Incremental cost-effectiveness for miscarriage prevention. RESULTS: The average costs per live birth of PGT-A were estimated as ¥39230.71, which is about 16.8% higher than that of the conventional treatment. Threshold analysis revealed that PGT-A would need to increase the pregnancy rate of 26.24-98.24% or a cost reduction of ¥4649.29 to ¥1350.71 to achieve the same cost-effectiveness. The incremental costs per prevented miscarriage was approximately ¥45600.23. The incremental cost-effectiveness for miscarriage prevention showed that the willingness to pay would be ¥43422.60 for PGT-A to be cost-effective. CONCLUSION: The present cost-effectiveness analysis demonstrates that embryo selection with PGTA is not suitable for routine applications from the perspective of healthcare providers in China, given the cumulative live birth rate and the high costs of PGTA.
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Aborto Espontáneo , Infertilidad , Diagnóstico Preimplantación , Femenino , Humanos , Embarazo , Aborto Espontáneo/genética , Aneuploidia , China , Análisis Costo-Beneficio , Fertilización In Vitro , Pruebas Genéticas/métodos , Diagnóstico Preimplantación/métodosRESUMEN
Bacillus velezensis GUAL210 was isolated from the rhizosphere of healthy pepper plants growing in high-incidence anthracnose fields in Guizhou, China. GUAL210 could be used as a potential biocontrol agent against pepper anthracnose and other soil-borne diseases. The GUAL210 genome consisted of a single circular chromosome 4,011,788 bp in length, with an average GC content of 46.41%, and did not harbor any plasmids. A total of 4,115 protein-coding genes, 27 rRNAs, 87 tRNAs, and 12 secondary metabolite biosynthesis gene clusters were identified. The products of the gene clusters included bacilysin, surfactin, bacteriocin, bacillaene, terpene, and so on, which might help host plants inhibit pathogens. The two clusters predicted to produce terpene had not typically been found in other Bacillus spp. The findings of this study will provide valuable data to explore the biocontrol mechanisms of B. velezensis strains.
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Bacillus , Genoma Bacteriano , Rizosfera , Bacillus/genética , ChinaRESUMEN
Tea (Camellia sinensis), which originated in southwest of China 60 - 70 million years ago, is widely consumed as a beverage for its potential enhancing effect on human health with rich polyphenol content (Pan et al. 2022). From October to December in 2021, a disease with symptoms similar to leaf spot affected the quality and yield of tea Puer (102°73 'E, 25°07' N), Yunnan province, China. Based on the survey, leaf spot symptoms were observed on approximately 60% of tea plants in a 5,700 m2 field. The symptoms initially appeared as shrinking, yellowing, and later became circular or irregular brown spots. To isolate the pathogen, 10 symptomatic leaves were collected from 10 trees, and portions of the diseased tissue (0.5×0.5 cm) were cut at the junction of infected and healthy tissues. After surface sterilization (0.5 min with 75% ethanol and 2 min with 3% NaOCl, washed three times with sterilized distilled water), the disinfected pieces were dried and plated onto potato dextrose agar (PDA) and incubated at 25°C in the dark for 5 days. Four single-spore isolates, FH-1, FH-5, FH-6 and FH-7, were obtained, these isolates were identical in morphology and in the sequences of internal transcribed spacer region [ITS] and translation elongation factor 1-alpha [TEF] genes. Therefore, the representative isolate FH-5 was used for further study. Fungal colonies were white or light yellow on PDA after 7 days incubated at 28ºC. Conidia were hyaline, round or oval, aseptate, occur singly or in clusters on hyphae or conidia stalks, and measured as 2.94 ± 1.79 × 1.82 ± 0.2 µm (n = 50). Primary conidiophores is Verticillium-like (Fig1.K,L), which generally formed first, 1-3-level verticillate, mostly with divergent branches and phialides, and measured as 16.67 ± 4.39 µm (n = 50). Secondary conidiophores is penicillate (Fig1.I,J), which generally appearing after one week, sometimes even more often branched, and with a length of 16.02 ± 3.83 µm (n = 50). The morphological features were consistent with the descriptions of Clonostachys rosea Schroers H.J. (Schroers et al. 1999). The pathogen was confirmed to be C. rosea by amplification and sequencing of the internal transcribed spacer region (ITS) and translation elongation factor 1-alpha (TEF) genes using primers ITS1/ITS4 and EF1-728F/EF1-986R, respectively (Fu Rongtao 2019). The sequences of PCR products were deposited in GenBank with accession numbers ON332533 (ITS) and OP080234 (TEF). BLAST searches of the obtained sequences revealed 99.22% (510/514 nucleotides) and 98.37% (241/245 nucleotides) homology with those of C. rosea HQ-9-1 form GenBank (MZ433177 and MZ451399, respectively). Phylogenetic analysis (MEGA 7.0) using the maximum likelihood method placed the isolate FH-5 in a well-supported cluster with C. rosea. The pathogenicity of FH-5 was tested through a pot assay. Ten healthy tea plants were scratched with a sterilized needle on the leaves. Plants were inoculated by spraying a spore suspension (105 spores·mL-1) of FH-5 onto leaves until runoff, and the control leaves sprayed with sterile water. Inoculated plants were put in an artificial climate box at 25â, 70% relative humidity. The pathogenicity test was replicated three times. Symptoms developed on all inoculated leaves but not on the control leaves. Lesions around the wound edge became pale yellow, and brown spots were first observed at 72 h after inoculation, and typical lesions similar to those observed on field plants appeared after two weeks. The same fungus was reisolated and identified based on the morphological characterization and molecular analyses (ITS and TEF) from the infected leaves but not from the noninoculated leaves. In addition, C. rosea has also been reported to cause diseases to broad bean (N. Afshari et al. 2017 ), garlic (Diaz et al. 2022), beet (Haque M.E et al. 2020) and other plants. To our knowledge, this is the first report of leaf spot on tea caused by C. rosea in China. This study provides valuable information for the identification and control of the leaf spot on tea.
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Tetrapanax papyrifer (Hook.) K. Koch, widely utilized in clinical practices in traditional Chinese medicine, is a medicinal plant whose dried stem pich exhibits activities such as lactation induction, diuresis, and anti-inflammatory effects. The species is native to the southwest of China, such as Guizhou and Yunnan provinces. It thrives in sunlight and warmth and is planted in fertile valleys in the region (Zhang et al. 2023). In July 2021, a leaf spot-like disease was observed on approximately 15% of T. papyrifer (Big T. papyrifer) in a field in Shibing County (127.2°E, 25.2°N), Guizhou Province, China. The symptomatic leaves displayed irregular, watery dark brown lesions with black conidiomata in gray centers and surrounded by yellow halos. To identify the causal agent leading to the disease, 15 symptomatic leaves from five trees in one field were collected. These leaves underwent surface sterilization, which included 30s in 75% ethanol, 2 min in 3% NaOCl, and three times of washing with sterilized distilled water. Thereafter, small pieces of the symptomatic leaf tissues (0.2 × 0.2 cm) were plated on PDA and incubated at 25°C for seven days (Fang 2007). Three isolates were obtained based on the improved single spore isolation method proposed by Gong et al. (2010), and named as GUTC 321, GUTC 523 and GUTC 873. The fungal colonies on PDA were villiform, creamy-white, whorled, and sparse aerial mycelium on the surface with black, gregarious conidiomata. The conidia were ellipsoid, mid brown to dark brown, mainly with 3-4 transverse septa, usually divided by longitudinal septum, often constricted at the septa, 21.8 (12.6-34.5) × 13.9 (8.8-19.8) µm (n=50). The morphological features were consistent with the descriptions of Pseudopithomyces chartarum (Ariyawansa et al. 2015). All three isolates exhibited identical morphological properties. The potential pathogen was confirmed as P. chartarum by amplification and sequencing of the internal transcribed spacer regions (ITS), large subunit ribosomal (LSU) and translation elongation factor 1 alpha (TEF1) genes with primers ITS4/ITS5, LROR/LR7 and EF-983F/EF-2218R, respectively (Ariyawansa et al. 2015; Jayasiriet al. 2019). BLASTn analyses of the sequences showed 100% identity among the three isolates and a high homology (ITS, 99.8%: 598/599; LSU, 100%: 853/853; and TEF1, 100%: 871/871) with those of P. chartarum sequences in GenBank (MT123059, OK655822, and MK360080, respectively). The sequences of the genes from isolate GUTC321 were deposited in GenBank under accession numbers OP269599 (ITS), OP237015 (LSU), and OR069689 (TEF1). Phylogenetic analyses of the concatenated ITS-LSU-TEF1 sequence (2,685 bp) of GUTC 321 using PhyloSuite 1.2.2 with PartitionFinder model revealed that the isolate clustered closely with P. chartarum isolate CBS 329.86T (Cecilia 1986). The pathogenicity of GUTC 321 was tested thereafter on ten healthy T. papyrifer plants grown in pots in growth chamber. The plants were inoculated by spraying with spore suspension (106 spores mL-1) of GUTC 321 or sterile water (control) onto leaves that had been slightly injured with sterilized SiO2 (0.1-0.25 mm) until runoff. The plants were maintained at 25°C in the growth chamber, and monitored for symptom development. Local lesions began to appear on all GUTC 321-inoculated leaves, but not on those of the control plants, 48 hours after inoculation. Seven days after the inoculation, lesions similar to those observed on field plants occurred on GUTC321-inoculated plants but not on the control plants, the lesions observed only in inoculated leaves. The same fungus was reisolated and identified based on the morphological characterization and molecular analyses (ITS, LSU and TEF1) from the infected leaves thus fulfilling Koch's postulates. To our knowledge, this is the first report of leaf spot on T. papyrifer caused by P. chartarum in China. Considering the significance of T. papyrifer in Chinese medicine, approximate management measures need to be developed and applied to control the disease in the crop.
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Tetrapanax papyriferus is an evergreen shrub native to China and traditionally used as a herbal medicine (Li et al., 2021). In September 2021, a serious leaf spot disease with symptoms similar to anthracnose was extensively observed on T. papyriferus in Shibing county (E 127°12'0", N 25°11'60"), Qiandongnan Miao and Dong Autonomous Prefecture, Guizhou province, China. Field surveys were conducted in about 1000 T. papyriferus plants in Shibing in September 2021. The incidence of the leaf spot on leaves was 45% to 60%, significantly reducing the quality of medicinal materials. The symptoms began as small yellow spots, developing a brown center and dark brown to black margin, and eventually the diseased leaves were wiltered and rotted. Symptomatic leaves were collected from 20 trees. Symptomatic tissue from diseased leaves was surface desinfected (0.5 min in 75% ethanol and 1 min in 3% NaOCl, washed three times with sterilized distilled water), small pieces of symptomatic leaf tissue (0.2 × 0.2 cm) were plated on potato dextrose agar (PDA) and incubated at 25°C for about 7 days (Fang. 2007). Three single-spore isolates were obtained (GUTC37, GUTC310 and GUTC311) and deposited in the collection of the Plant Pathology Deparment, College of Agriculture, Guizhou University, China (GUCC) (with the accession numbers, GUCC220241, GUCC220242, GUCC220243 respectively). These isolates were identical in morphology and in the sequences of internal transcribed spacer region [ITS], glyceraldehy-3-phosphate dehydrogenase [GAPDH], chitin synthase [CHS-1], actin [ACT], and calmodulin [CAL] genes (White et al. 1990; Carbone and Kohn 1999; Templeton et al. 1992). Therefore, the representative isolate GUTC37 was used for further analysis. The pathogenicity of GUTC37 was tested through a pot assay. Plants were inoculated by spraying a spore suspension (106 spores·ml-1) of isolated strains onto leaves until runoff, and the control leaves sprayed with sterile water. The inoculated plants were incubated in a growth chamber at 28 â and 95% relative humidity for 10 days. Pathogenicity tests were repeated three times (Fang. 2007). The symptoms developed on the inoculated leaves, while control remained asymptomatic. The lesions were first visible 72 h after inoculation, and typical lesions like those observed on field plants appeared after 10 days. The same fungus was reisolated and identified based on the morphological characterization and molecular analyses from the infected leaves but not from the non-inoculated leaves. Results of pathogenicity experiments of isolated fungi fulfilled Koch's postulates. Fungal colonies on PDA were villiform, creamy-white or greyish, aerial mycelium pale grey, dense, surface partly covered with orange conidial masses. The conidia were abundant, oval-ellipsoid, aseptate, and 13.89 (11.62 to 15.21) × 5.21 (4.39 to 5.65) µm (n=50). Appressorium were greyish green, nearly ovoid to cylindrical, 9.64 (6.62 to 14.61) × 6.33 (5.45-7.72) µm (n=50). The morphological features were consistent with the descriptions of Colletotrichum fructicola Prihast., L. Cai & K.D. Hyde (Prihastuti et al. 2009). The pathogen was identified to be C. fructicola by amplification and sequencing of the five genes. The sequences of the PCR products were deposited in GenBank with accession numbers OP143657 (ITS), OP177868 (GAPDH), OP177865 (CHS-1), OP278677 (ACT) and OP177862 (CAL). BLAST searches of the obtained sequences revealed 100% (509/509 nucleotides), 99.63% (269/270 nucleotides), 99.31% (287/289 nucleotides), 99.29% (280/282 nucleotides), and 99.86% (728/729 nucleotides) homology with those of C. fructicola in GenBank (JX010165, JX010033, JX009866, FJ907426, and JX009676, respectively). Phylogenetic analysis (MEGA 7.0) using the maximum likelihood method placed the isolate GUTC37 in a well-supported cluster with C. fructicola. To our knowledge, this is the first report of anthracnose on T. papyriferus caused by C. fructicola in Guizhou, China. This study provides valuable information for the identification and control of the anthracnose on T. papyriferus.
RESUMEN
Tobacco (Nicotiana tabacum L.) is an important economic crop belonging to family Solanaceae and is widely cultivated in China (Basit 2021). From April to July in 2022, a foliar disease with symptoms similar to grey spot was extensively observed on tobacco in Guangxi Province (24°52' N, 111°23' E), China. Field surveys were conducted in 18 towns and the disease incidence was 0.89% to 6.95%. Symptomatic leaves displayed irregular, dark brown lesions surrounded by yellow halos and accompanied with black conidiomata in gray centers (Fig 1A-E). Symptomatic leaves were collected from 54 different tobacco plants. After surface sterilization (0.5 min in 75% ethanol and 1 min in 3% NaOCl, washed three times with sterilized distilled water), small pieces of symptomatic leaf tissue (0.2 × 0.2 cm) were plated on PDA and incubated at 25°C for 5 days (Fang 2007). Three single-spore isolates, GUCC BZ6-3, GUCC LJ3-4, and GUCC XH1-13 were obtained, which were identical in morphology and molecular analysis. Therefore, the representative isolate GUCC BZ6-3 was used for further study. The colonies on PDA were villiform, greyish (Fig 1F-G). Conidia were abundant, ovoid, with 2-6 transverse septa and 1-2 longitudinal septa 12.60 (9.43 to 14.76) × 4.30 (3.57 to 5.14) µm (n=50) (Fig 1H-S). The morphological features were consistent with Alternaria alstroemeriae E.G. Simmons & C.F. Hill (Simmons 2007; Nishikawa & Nakashima, 2013). The pathogen was confirmed to be A. alstroemeriae by amplification and sequencing of the ITS, GAPDH, LSU, TEF1, and RBP2 genes using primers ITS1/ITS4, gpd1/gpd2, LSU1Fd/LR5, EF1-728F/EF1-986R, and RPB2-5F2/fRPB2-7cR, respectively (Woudenberg 2013). The sequences of the PCR products were deposited in GenBank with accession numbers ON693856 (RBP2), ON714497 (ITS), ON694345 (GAPDH), ON931420 (TEF1) and ON714499 (LSU). BLAST searches of the obtained sequences revealed 99% (565/567 nucleotides), 99% (577/579 nucleotides), 99% (908/911 nucleotides), 99% (238/239 nucleotides), and 99% (751/753 nucleotides) homology with those of A. alstroemeriae in GenBank (MH863036, KP124154, MH874589, KP125072, and KP124765, respectively). Phylogenetic analyses of the sequence data consisted of Bayesian and Maximum likelihood analyses of the combined aligned dataset (MEGA 7.0 and PhyloSuite 1.2.2). The GUCC BZ6-3 in a well-supported cluster with A. alstroemeriae (Fig 2). The pathogen was thus identified as A. alstroemeriae based on morphological characterization and molecular analyses. The pathogenicity of GUCC BZ6-3 was tested through pot assay and carried out three times (Fang 2007). Ten healthy 30-day-old tobacco plants were inoculated by spraying a spore suspension (106 spores·ml-1) of strain GUCC BZ6-3 onto leaves until runoff, and the control leaves were sprayed with sterile water. The plants were maintained at 28°C with high relative humidity (95%) in a growth chamber. The symptoms developed on all inoculated leaves but not on the control. The lesions were first visible 48 h after inoculation, and typical lesions similar to those observed on field plants appeared after 7 days. The same fungus was reisolated and identified based on the morphological characterization and molecular analyses from the infected leaves but not from the noninoculated leaves. Results of pathogenicity experiments fulfilled Koch's postulates. To our knowledge, this is the first report of grey spot disease on tobacco caused by A. alstroemeriae in China. Our findings would be of great importance for the diagnosis and control of the emerging grey spot on tobacco.
RESUMEN
Correction for 'High-efficiency and high-fidelity ssDNA circularisation via the pairing of five 3'-terminal bases to assist LR-LAMP for the genotyping of single-nucleotide polymorphisms' by Taiwen Li et al., Analyst, 2022, https://doi.org/10.1039/d2an01042a.
RESUMEN
The poor fidelity of T4 DNA ligase has always limited the simple detection of single-nucleotide polymorphisms (SNPs) and is only applicable to some special SNP types. This study developed a highly sensitive and specific detection method for SNPs based on high-fidelity single-stranded circularisation. It used T4 DNA ligase and rolling circle amplification (RCA) plus loop-mediated isothermal amplification (LAMP). Surprisingly, the cyclisation stage's efficiency greatly improved. The ligation fidelity was almost perfect via the unique pairing pattern between a long-paired base at the 5' terminus and only five bases at the 3' terminus on linear single-stranded DNA (l-DNA). Subsequently, LR-LAMP was performed and combined with the circularisation step for the simple detection of SNPs. The results showed that even 100 aM targets could be detected correctly and that a mutation rate of 0.1% or even 0.01% could be analysed via naked-eye visualisation or fluorescence detection, respectively. In addition, genomic DNA samples were used to evaluate the method, which indicated that it could effectively distinguish the SNPs of RPA190-T1145A in Phytophthora infestans. This strategy may play an important role in both circularisation of single-stranded DNA and detecting arbitrary SNPs.
Asunto(s)
Técnicas de Amplificación de Ácido Nucleico , Polimorfismo de Nucleótido Simple , ADN/genética , ADN Ligasas , ADN de Cadena Simple/genética , Genotipo , Técnicas de Amplificación de Ácido Nucleico/métodosRESUMEN
PURPOSE: We have combined analysis of clinical and laboratory markers to try to find an optimal model to predict venous thromboembolism in isocitrate dehydrogenase 1 (IDH1) wild-type glioblastoma (GBM) by a prospective research. METHODS: Patients with newly histologically confirmed IDH1 wild-type (IDH1wt) GBM were recruited for this study. Status of IDH1, PTEN, P53, BRAF, MGMT promoter methylation (MGMTp), and TERT promoter (TERTp) was determined using genetic sequencing through polymerase chain reaction (PCR). Amplification of EGFR was established through fluorescence in situ hybridization (FISH). Competing risk regression model was performed to calculate the risk of VTE. Clinical and laboratory parameters that were independently predicted risk of VTE were used to develop a risk assessment model (RAM). RESULTS: One hundred thirty-one patients with IDH1wt GBM were included in the present analysis. A total of 48/131 patients (36.6%) developed VTE. D-dimer, ECOG score, and EGFR amplification were suggested to be significantly associated with the VTE risk in multivariable analysis. High ECOG score (>2), high D-dimer (>1.6 µg/ml), and EGFR amplification were used as the strongest independent predictors of increased risk of VTE. The cumulative incidence of VTE was 17.2% for patients with score 0 (n =29), 23.6% for patients with score 1 (n =55), and 63.8% for patients with score 2 (n = 35) or score 3 (n = 12) by application of a RAM. CONCLUSIONS: In IDH1wt GBM patients, by applying a VTE risk assessment model, we could identify patients with a very high and low risk of VTE.
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Neoplasias Encefálicas , Glioblastoma , Tromboembolia Venosa , Biomarcadores , Neoplasias Encefálicas/patología , Receptores ErbB/genética , Glioblastoma/patología , Humanos , Hibridación Fluorescente in Situ , Isocitrato Deshidrogenasa/genética , Mutación , Estudios Prospectivos , Tromboembolia Venosa/etiología , Tromboembolia Venosa/genéticaRESUMEN
Background: Lower limb ischemia due to arterial stenosis is a major complication in patients with diabetes mellitus (DM). Liraglutide is a long-acting analogue of a glucagon-like peptide 1 (GLP-1) receptor agonist used for lowering blood glucose in patients with DM, and is believed to possess cardiovascular protective effects. The aim of this study was to investigate whether liraglutide has a protective effect on blood vessels and alleviates vascular intimal hyperplasia in streptozotocin (STZ)-induced rabbits with DM and its molecular mechanism. Methods: Rabbits with DM were induced by STZ, and a lower limb ischemia model was established. The animals were divided into a control group, DM-injury group and liraglutide treatment group. Pathological staining was used to observe the intimal growth, analyze the oxidation levels of malondialdehyde (MDA), superoxide dismutase (SOD) and plasma glutathione peroxidase (GSH-Px), and analyze the changes in expression of marker proteins and signaling pathway proteins by Western blotting. A hyperglycemia (HG)-injured vascular smooth muscle cells (VSMCs) model was established to analyze reactive oxygen species (ROS) levels, Cell-Counting Kit-8 (CCK-8) was used to analyze cell proliferation, scratch assay and Transwell Migration Assay to analyze cell migration, flow cytometry to analyze apoptosis and Western blotting was used to analyze changes in the expression of marker and signaling pathway proteins. Results: The results of pathological staining showed that intimal hyperplasia was severe after diabetes-induced lower limb ischemia in rabbits at 4 weeks, and liraglutide treatment reduced symptoms. Liraglutide treatment significantly decreased MDA content, increased SOD, GSH-Px content, and augmented total antioxidant capacity levels in tissues. The results of Western blotting analysis showed that E-cadherin, mitochondrial membrane potential 9 (MMP-9), proliferating cell nuclear antigen (PCNA), and type I collagen protein expression levels were significantly decreased after liraglutide treatment compared with the DM injury group. The results indicated that liraglutide inhibited epithelial-mesenchymal transition (EMT) progression, vascular cell proliferation and migration and collagen production. Liraglutide inhibits transforming growth factor beta 1 (TGF-ß1)/Smad3 signaling pathway protein expression. In vitro assays have shown that liraglutide reduces cellular ROS levels, inhibits cell proliferation and migration and promotes apoptosis. Liraglutide down-regulated the expression of E-cadherin, MMP-9, PCNA, type I collagen protein as well as the TGF-ß1/Smad3 signaling pathway, but this effect could be reversed by tumor necrosis factor alpha (TNF-α). Conclusion: Liraglutide can significantly improve tissue antioxidant capacity, reduce vascular cell proliferation and migration via the TGF-ß1/Smad3 signaling pathway, inhibit the EMT and collagen production processes, and alleviate hyperglycemia(HG)-induced lower limb ischemia and intimal hyperplasia.
Asunto(s)
Diabetes Mellitus , Hiperglucemia , Lesiones del Sistema Vascular , Animales , Antioxidantes/farmacología , Cadherinas/farmacología , Colágeno Tipo I/farmacología , Constricción Patológica , Hiperplasia/tratamiento farmacológico , Liraglutida/farmacología , Liraglutida/uso terapéutico , Metaloproteinasa 9 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/farmacología , Antígeno Nuclear de Célula en Proliferación/metabolismo , Antígeno Nuclear de Célula en Proliferación/farmacología , Conejos , Especies Reactivas de Oxígeno/farmacología , Transducción de Señal , Superóxido Dismutasa , Factor de Crecimiento Transformador beta1/metabolismo , Factor de Crecimiento Transformador beta1/farmacologíaRESUMEN
Rhododendron delavayi Franch, a member of Ericaceae family, is globally famous for its garden flowers with significant ornamental value (Liu et al., 2020). In July 2020 and 2021, a disease survey of R. delavayi groves was conducted in Baili Azalea Forest Area (N27°10'-27°20', E 105°04'-106°04'). We arbitrarily selected an area with around 280 R. delavayi trees covering 2.5 hectares in R. delavayi grove where 20-35% of leaves showed symptoms of anthracnose. Typical symptoms included elliptical to irregularly shaped brown lesions on leaves and masses of black dots clustered on it. About 30 pieces of leaves with anthracnose lesions were collected. A few black dots were picked from the lesions with a sterilized needle, plated on water agar and incubated at 25â for 12 h to observe spore germination (Fang, 2007). Then the germinated spores were transferred onto PDA medium for further purification and morphological observation. Fourteen single-spore isolates with similar morphology were obtained. The surface of the colony was white or gray and spongy; the edge was smooth; and the back side was pinkish brown after 7 days of growth on PDA. Conidia were spindle-shaped, transparent, 11.1-16.6×3.6-4.9 µm (n=50). Appressorium from conidia was nearly ovate or proximate, brown or dark brown in color, 4.3-10.3 ×3.2-7.6 µm (n=50). These characteristics are consistent with Colletotrichum fioriniae reported by Shivas and Tan (2009). DNA was extracted from a representative isolate MYDJ12. The internal transcribed spacer region (ITS), the glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ß-tubulin (TUB), actin (ACT), and chitin synthase 1 (CHS-1) genes were amplified using primer pairs described by Damm et al. (2012). The sequences were deposited in GenBank with accession number MW692854 (ITS), MW727518 (GAPDH), MW727519 (TUB2), MW727520 (ACT), and MW727521 (CHS-1). BLASTN searches of the ITS, GADPH, TUB2, ACT and CHS-1 genes revealed 100% (540/540 nucleotides), 100% (254/254 nucleotides), 99.38% (4488/491 nucleotides), 98.77% (242/245 nucleotides) and 100% (282/282 nucleotides) homology with those of C. fioriniae CBS:128517T in GenBank (NR_111747, JQ948622, JQ949943, JQ949613 and JQ948953 respectively). The phylogenetic tree showed the isolate MYDJ12 to cluster with C. fioriniae CBS:128517T. Finally, two-year old R. delavayi plants (n=5) were inoculated by wounding with a syringe needle and placing 10 µL of spore suspension (106 spores per mL) of the isolate MYDJ12 on three leaves per plant. Control leaves were inoculated with sterile water. The experiment was conducted twice. Inoculated leaves were wrapped in parafilm tape and then the plants were placed in a greenhouse at 25°C with high relative humidity (90 to 95%). Seven days after incubation, brown lesions appeared, similar to those observed in the grove. Black dots clustered on the lesions after 15 days. Re-isolation was conducted 20 days after inoculation. From all the five inoculated plants, similar symptoms were observed, and the same pathogen was re-isolated. One of the isolates was selected for morphological observation and multi-gene (ITS, GAPDH, ACT, TUB2 and CHS-1) analysis indicated the reisolated fungus to be C. fioriniae. No fungal pathogens were isolated from mock inoculated plants. This study can provide effective management and useful information for the control of this disease on R. delavayi in Baili Azalea Forest Area. References: Damm, U., et al. 2012. Stud Mycol 73: 37. Fang, Z. D. 2007. Research Methods of Plant Diseases (Third edition). China Agriculture Press. Liu, J., et al. 2020. Mitochondrial DNA B 5:37. Shivas, R, G; Tan, Y, P. 2009. Fungal Divers 39:111.
RESUMEN
Photinia × fraseri is a well-known evergreeen ornamental tree. Owing to its flower-like red leaves and its ability to tolerate stressful environments, P. fraseri is widely cultured as a fast-growing hedge in southern China. From July to September in 2021, a disease with symptoms similar to leaf spot was extensively observed on P. fraseri in Daozhen county (28° 51 'N, 107° 57 'E), Zunyi, Guizhou province, China. About 500 plants were surveyed and the incidence of leaf spot on P. fraseri leaves was 35% to 70%, significantly reducing the ornamental and economic value. The symptomatic leaves displayed irregular, watery dark brown lesions with black conidiomata in gray centers, and 10 symptomatic leaves were collected from 10 trees. After surface sterilization (0.5 min in 75% ethanol and 2 min in 3% NaOCl, washed three times with sterilized distilled water) (Fang 2007), small pieces of symptomatic leaf tissue (0.2 × 0.2 cm) were plated on potato dextrose agar (PDA) and incubated at 25°C for about 7 days. Three single-spore isolates, GZAAS 21-0327, GZAAS 21-0328 and GZAAS 21-0329, were obtained, which were identical in morphology and molecular analysis. Therefore, the representative isolate GZAAS 21-0328 was used for further study. The pathogenicity of GZAAS 21-0328 was tested through a pot assay. Ten healthy plants were scratched with a sterilized needle on the leaves. Plants were inoculated by spraying a spore suspension (106 spores mL-1) of GZAAS 21-0328 onto leaves until runoff, and the control leaves sprayed with sterile water. The plants were maintained at 28°C with high relative humidity (95%) in a growth chamber. The pathogenicity test was carried out three times (Fang 2007). The symptoms developed on all inoculated leaves but not on the control leaves. The lesions were first visible 72 h after inoculation, and typical lesions similar to those observed on field plants appeared after 15 days. The same fungus was reisolated and identified based on the morphological characterization and molecular analyses (ITS, TUB and TEF) from the infected leaves but not from the noninoculated leaves. Results of pathogenicity experiments of isolated fungi fulfilled Koch's postulates. Fungal colonies on PDA were villiform, creamy-white and sparse aerial mycelium on the surface with black, gregarious conidiomata. The conidia were fusoid, ellipsoid, straight to slightly curved, 4-septate, septa darker than the rest of the cell, and 23.0 (21.0 to 27.0) × 6.0 (5.0 to 7.0) µm (n=50). The morphological features were consistent with the descriptions of Neopestalotiopsis asiatica Maharachch. & K.D. Hyde (Maharachchikumbura et al. 2012; Maharachchikumbura et al. 2014; Farr et al. 2022). The pathogen was confirmed to be N. asiatica by amplification and sequencing of the internal transcribed spacer region (ITS), the partial ß-tubulin (TUB) and partial translation elongation factor 1-alpha (TEF) genes using primers ITS4/ITS5, T1/Bt-2b and EF1-728F/EF-2, respectively (Maharachchikumbura et al. 2014). The sequences of PCR products were deposited in GenBank with accession numbers OK563071 (ITS), OK584020 (TUB) and OK663023 (TEF). BLAST searches of the obtained sequences revealed 100% (482/482 nucleotides), 99.05% (419/421 nucleotides), and 99.33% (891/897 nucleotides) homology with those of N. asiatica in GenBank (JX398983, JX399018 and JX399049, respectively). Phylogenetic analysis (MEGA 6.0) using the maximum likelihood method placed the isolate GZAAS 21-0328 in a well-supported cluster with N. asiatica. The pathogen was thus identified as N. asiatica based on the morphological characterization and molecular analyses. To our knowledge, this is the first report of leaf spot on P. fraseri caused by N. asiatica in China. This study provides valuable information for the identification and control of the leaf spot on Photinia × fraseri.
RESUMEN
Rhododendron delavayi is an evergreen shrub with large scarlet flowers that make it highly attractive as an ornamental species. The species is native to southwest China (Cai et al. 2015). From May to July in 2022, symptoms of leaf spot were observed on R. delavayi over a wide portion of the Baili Azalea Forest Area (N 27°10'-27°20', E 105°04'-106°04'), Guizhou Province, China. About 500 plants were surveyed and the incidence of leaf spot on R. delavayi leaves was 20 to 30%, significantly reducing their ornamental and economic value. The affected leaves had irregular, dark brown lesions with a clear blackish brown boundary and black conidiomata in a grayish center. To isolate the pathogen, 15 symptomatic leaves were collected from 10 plants. A few black dots were picked from the lesions with a sterilized needle, plated on water agar and incubated at 25â for 24 h to observe spore germination (Choi et al. 1999). Then the germinated spores were transferred onto PDA for further purification and morphological observation. Three single-spore isolates (GUDJ 61, GUDJ 62, GUDJ 63) that produced identical in morphology were obtained. The isolate GUDJ 61 was used for further study. Colonies on PDA grew velvety white on the upper surface and light yellow on the lower surface. Conidia were 5-celled, spindle- to ellipsoid-shaped, straight or slightly curved, 4-septate, and measured 39.0 ± 3.7 × 10.4 ± 0.79 µm (n=50). The morphological features were consistent with the description of Pestalotiopsis scoparia Maharachch., K.D. Hyde & Crous, (Maharachchikumbura et al. 2014). The pathogen was confirmed to be P. scoparia by amplification and sequencing of the internal transcribed spacer region (ITS), the partial ß-tubulin (TUB), and the partial translation elongation factor 1-alpha (TEF) genes using primers ITS4/ITS5, T1/Bt-2b, and EF1-728F/EF-2, respectively. Sequences from PCR amplification were deposited in GenBank with accession numbers OP048045 (ITS), OP058111 (TUB) and OP058114 (TEF), respectively. BLAST searches of the sequences revealed 99% (549/552 nt), 99% (711/714 nt), and 82% (130/158 nt) homology with those of P. scoparia CBS 176.25T form GenBank (KM199330, KM199393, and KM199478), respectively. Phylogenetic analysis (MEGA 7.0) using the maximum likelihood method placed the isolate GUDJ 61 in a well-supported cluster with P. scoparia. The pathogen was thus identified as P. scoparia based on the morphological characterization and molecular analyses. The pathogenicity of GUDJ 61was tested through a pot assay. Ten healthy R. delavayi plants were scratched with a sterilized needle (0.45 mm in diameter) on three leaves per plant. Plants were inoculated by spraying a spore suspension (106 spores mL-1) of GUDJ 61 onto leaves until runoff, and the control leaves sprayed with sterile water. The plants were maintained at 25°C and 75% relative humidity in a growth chamber. The pathogenicity test was repeated three times (Fang 2007). After 12 days, the treated leaves developed brown lesions similar to those in the field, while the control had no symptoms. The same fungus was reisolated from the infected leaves and identified based on a morphological characterization and molecular analyses. These results fulfilled Koch's postulates. To our knowledge, this is the first report of leaf spot on R. delavayi caused by P. scoparia in China. The fungal pathogen identification will provide valuable information for prevention and management of leaf spot disease associated with R. delavayi.