Zanthoxylum bungeanum is an economically and ecologically significant species, but its production and quality are increasingly threatened by widespread leaf defoliation disease in China. The absence of molecular identification and genomic characterization of the causal pathogen has hindered both fundamental research on host–pathogen interactions and the development of effective control measures. In this study, the fungal isolate PL-2024a was isolated from defoliated Z. bungeanum and established as the causal agent via Koch's postulates. Through an integrated morphological analysis that included histopathology (optical, scanning, and transmission electron microscopy) and in vitro culture characteristics, coupled with phylogenetic analyses, we provided the first molecular confirmation and robust characterization of the pathogen as Marssonina zanthoxyli, a species previously described solely by oversimplified morphological characteristics. Subsequent whole-genome sequencing, de novo assembly, and comprehensive annotation of M. zanthoxyli yielded a high-quality genome assembly spanning 80.49 Mb, comprising 19 contigs and encoding 8,494 putative protein-coding genes. Pathogenicity-related functional repertoire analysis identified 354 CAZymes, 100 effector proteins, 70 CYP450s, and 159 enzymes involved in secondary metabolic pathways. Comparative genomic analyses elucidated the phylogenomic evolutionary relationships, estimated divergence times, and characterized gene family expansion/contraction events within M. zanthoxyli. Molecular dating revealed that M. zanthoxyli diverged from its closest relatives approximately 18.5 MYA. Additionally, 221 lineage-specific genes were identified in M. zanthoxyli, with the most enriched functional domains including DNA/RNA polymerases and reverse transcriptases associated with long terminal repeats. This study identified and genomically characterized M. zanthoxyli, clarifying its taxonomic status and revealing pathogenicity’s genetic basis. These findings lay a crucial foundation for understanding Z. bungeanum-M. zanthoxyli interactions and developing targeted leaf defoliation management strategies.

Leaf rust caused by Coleosporium zanthoxyli is a destructive disease that threatens Zanthoxylum bungeanum plantations. To address this, screening for resistant cultivars and exploring their resistance mechanisms are crucial for effective disease management. However, the mechanisms underlying Z. bungeanum's resistance remain unclear. In this study, we conducted in vivo and in vitro experiments to screen for the resistant cultivar Qiujiao (QJ) and the susceptible cultivar Fengxian Dahongpao (FD). Subsequently, the resistance mechanisms of Z. bungeanum were analyzed by integrating transcriptome and metabolome, the result showed the flavonoid pathway served as the primary metabolic pathway for QJ to confer resistance against C. zanthoxyli. Upon infection with C. zanthoxyli, the key genes (PAL, CHI, and HCT) and enzymes (PAL, C4H, and 4CL) involved in the flavonoid pathway were upregulated in QJ, and the total flavonoid content was increased in QJ. Additionally, eight flavonoids from this pathway demonstrated inhibitory effects on C. zanthoxyli spore germination, with naringenin and phloretin exhibiting the stronger activity. Collectively, the flavonoid pathway plays a dominant role in the resistance of Z. bungeanum leaves against C. zanthoxyli.

BACKGROUND:Pine wood nematodes (PWD) cause significant threat to ecosystems and forestry economies, and the long-term use of commercial fungicides has led to environmental pollution and ecological imbalance. Therefore, it is urgent to develop effective and eco-friendly plant-based derivatives to control PWD. RESULT:A series of rosin-based nematicides were prepared, and their insecticidal activity was evaluated on pine wood nematodes. The result indicated that dehydroabietic acid-based amide derivatives-3q (DAAD-3q) exhibited the highest nematocidal activity, with the half-lethal concentration (LC50) of 95.9 μg/mL. Quantum chemical calculations revealed that the amide bond in DAAD-3q enhances binding to target sites. Physiological studies showed that DAAD-3q disrupted pine nematode microstructure, induced oxidative stress, and reduced glutathione S-transferase (GST) enzyme activities. Molecular docking revealed various interaction forces between DAAD-3q and GST, including hydrogen bonding and hydrophobic interactions. Metabolomic analysis indicated that DAAD-3q interferes with energy and lipid metabolism, while transcriptomic profiling showed alterations in genes related to development, metabolism, and antioxidant pathways. These molecular perturbations are associated with increased reactive oxygen species (ROS) production and decreased GST enzymatic activities, ultimately contributing to the death of pine wood nematodes. CONCLUSION:This research successfully prepared an efficient nematicide agent and explored its action mechanism, providing theoretical guidance for the green prevention and control of pine wood nematodes. © 2025 Society of Chemical Industry.

Juniperus przewalskii, a keystone species in China's ecologically fragile Sanjiangyuan region, faces severe threats from Gymnosporangium pleoporum rust. This study establishes chitooligosaccharides (COS) as potent antifungal agents against G. pleoporum, dose-dependently suppressing teliospore germination and viability. Integrated physiological analyses revealed COS-induced severe membrane damage evidenced by electrolyte leakage, soluble protein efflux, SEM-confirmed structural deformities, and elevated malondialdehyde indicating lipid peroxidation. Concurrently, COS triggered oxidative catastrophe via reactive oxygen species accumulation with suppression of antioxidant enzymes, while collapsing energy metabolism through adenosine triphosphate depletion and inhibition of electron transport chain enzymes. Transcriptomics identified concentration-dependent differential expression in energy metabolism pathways (glycolysis, oxidative phosphorylation, fatty acid degradation), alongside disrupted protein synthesis and redox homeostasis. Crucially, nine viability-correlated downregulated core genes, including putative orthologs for oxidative defense and aromatic amino acid biosynthesis, exhibited lineage-specific functions. Collectively, COS acts as a multi-target antifungal agent directly disrupting membrane integrity, redox homeostasis, and energy / protein metabolism in rust fungi, distinct from plant-induced resistance. This study establishes the scientific foundation for COS deployment against J. przewalskii rust disease, highlighting its eco-compatible potential through targeted exploitation of essential pathogen vulnerabilities. Furthermore, it positions COS as a cornerstone for precision forestry therapeutics that concurrently achieve pathogen suppression and ecological integrity preservation in vulnerable montane ecosystems.

Prickly ash, an economically significant industrial crop valued for its culinary, medicinal, and essential oil applications, is widely cultivated across numerous countries. However, its sustainable production is increasingly threatened by various diseases, with Fusarium solani-induced root rot emerging as one of the most devastating pathogens. The escalating prevalence of root rot, compounded by the lack of effective control measures, underscores the urgent need for sustainable management strategies. This study explored the potential of rhizosphere microorganisms as biocontrol agents against F. solani, with a particular focus on Bacillus species as environmentally friendly alternatives for integrated disease management. Through comprehensive screening and characterization, B. velezensis P87 was identified as the most potent antagonist, exhibiting stable antifungal activity through the production of lipopeptides that effectively inhibit F. solani growth and spore germination. Greenhouse experiments demonstrated that B. velezensis P87 exhibits significant therapeutic and protective efficacy against root rot in prickly ash, with pre-inoculation priming of seedlings resulting in higher control efficiency. Additionally, B. velezensis P87 enhanced chlorophyll content, defensive enzyme activities, and the accumulation of osmolytes (soluble sugars, proteins, and proline) and lignin, thereby promoting plant growth and health. Transcriptomic analysis revealed that B. velezensis P87 priming activated key defense-related pathways, including MAPK signaling, plant hormone signal transduction, and phenylpropanoid biosynthesis, leading to the significant upregulation of defense- and growth-related genes. This study highlights the potential of B. velezensis P87 as an effective biocontrol agent for managing root rot and promoting growth in prickly ash, offering a promising solution for sustainable cultivation practices.

Stem canker of Zanthoxylum bungeanum is a destructive forest disease, caused by Fusarium zanthoxyli, poses a serious threat to the cultivation of Z. bungeanum. The lack of research on effector proteins in F. zanthoxyli has severely limited our understanding of the molecular interactions between F. zanthoxyli and Z. bungeanum, resulting in insufficient effective control technologies for this disease. In this study, a total of 137 effector proteins (FzEPs) were predicted and characterized based on whole genome of F. zanthoxyli, with an average length of 215 amino acids, 8 cysteine residues, and a molecular weight of 23.06 kD. Besides, the phylogenetic evolution, conserved motifs, domains and annotation information of all the 137 effectors were comprehensively demonstrated. Moreover, transcriptomic analysis indicated that 24 effector genes were significantly upregulated in the early infection stages of F. zanthoxyli, which was confirmed by RT-qPCR. Following, the 24 effector DEGs were cloned and transiently over-expressed in the leaves of tobacco to evaluate their effects on the plant’s innate immunity. It was found that effector proteins FzEP94 and FzEP123 induced pronounced programmed cell death (PCD), callose deposition, and reactive oxygen species (ROS) burst in tobacco leaves, whereas FzEP83 and FzEP93 significantly suppressed PCD induced by INF1, accompanied by a less pronounced callose accumulation and ROS burst. In this study, we systematically characterized and functionally analyzed the effector proteins of F. zanthoxyli, successfully identifying four effector proteins that can impact the innate immune response of plants. These findings enhance our understanding of effector protein functions in F. zanthoxyli and offer valuable insights for future research on molecular interactions between F. zanthoxyli and Z. bungeanum.

Abstract Background Fusarium zanthoxyli is a destructive pathogen causing stem canker in prickly ash, an ecologically and economically important forest tree. However, the genome lack of F. zanthoxyli has hindered research on its interaction with prickly ash and the development of precise control strategies for stem canker. Results In this study, we sequenced and annotated a relatively high-quality genome of F. zanthoxyli with a size of 43.39 Mb, encoding 11,316 putative genes. Pathogenicity-related factors are predicted, comprising 495 CAZymes, 217 effectors, 156 CYP450s, and 202 enzymes associated with secondary metabolism. Besides, a comparative genomics analysis revealed Fusarium and Colletotrichum diverged from a shared ancestor approximately 141.1 ~ 88.4 million years ago (MYA). Additionally, a phylogenomic investigation of 12 different phytopathogens within Fusarium indicated that F. zanthoxyli originated approximately 34.6 ~ 26.9 MYA, and events of gene expansion and contraction within them were also unveiled. Finally, utilizing conserved domain prediction, the results revealed that among the 59 unique genes, the most enriched domains were PnbA and ULP1. Among the 783 expanded genes, the most enriched domains were PKc_like kinases and those belonging to the APH_ChoK_Like family. Conclusion This study sheds light on the genetic basis of F. zanthoxyli’s pathogenicity and evolution which provides valuable information for future research on its molecular interactions with prickly ash and the development of effective strategies to combat stem canker.

Stem canker is a highly destructive disease that threatens prickly ash plantations in China. This study demonstrated the effective control of stem canker in prickly ash using chitosan priming, reducing lesion areas by 46.77 % to 75.13 % across all chitosan treatments. The mechanisms underlying chitosan-induced systemic acquired resistance (SAR) in prickly ash were further investigated. Chitosan increased H2O2 levels and enhanced peroxidase and catalase enzyme activities. A well-constructed regulatory network depicting the genes involved in the SAR and their corresponding expression levels in prickly ash plants primed with chitosan was established based on transcriptomic analysis. Additionally, 224 ZbWRKYs were identified based on the whole genome of prickly ash, and their phylogenetic evolution, conserved motifs, domains and expression patterns of ZbWRKYs were comprehensively illustrated. The expression of 12 key genes related to the SAR was significantly increased by chitosan, as determined using reverse transcription-quantitative polymerase chain reaction. Furthermore, the activities of defensive enzymes and the accumulation of lignin and flavonoids in prickly ash were significantly enhanced by chitosan treatment. Taken together, this study provides valuable insights into the chitosan-mediated activation of the immune system in prickly ash, offering a promising eco-friendly approach for forest stem canker control.

Pine wilt disease (PWD) is a globally significant quarantine forest disease caused by Bursaphelenchus xylophilus ( PWN ), resulting in substantial ecological and economic losses. Traditional nematode management practices are neither cost-effective nor environmentally friendly, prompting the exploration of biocontrol as a promising alternative for managing this devastating forest disease. Obtaining novel and specific biocontrol agents is extremely crucial for the effective and precise control of PWD. In the present study, a total of 136 endophytic isolates were obtained from the roots, stems and needles of Pinus tabuliformis in the Qinling Mountains of China , which were then subjected to nematocidal activity assay against PWN in vitro . Nine endophytic bacterial isolates exhibited exceptionally strong nematocidal capacity, with a corrected mortality rate exceeding 90 %, which were then identified as the genus of Bacillus through morphological features, endospore staining, and 16S rDNA sequencing, with one strain as B. mycoides , two as B. cereus , and six as B. velezensis . Additionally, the inhibition effects of the three Bacillus species on the reproduction of PWN in vitro was assessed using an original detection model, with B. velezensis Pt-RP9 identified as the most promising strain. Subsequently, the biocontrol efficacy of B. velezensis Pt-RP9 against PWD was evaluated in greenhouse experiments. Pt-RP9 demonstrated significant biocontrol effectiveness against PWD, with control efficiencies ranging from 31.25 % to 68.89 % across all treatments, particularly showing improved efficacy when pine seedlings were pre-treated with Pt-RP9 before PWN inoculation. Furthermore, pine seedlings treated with Pt-RP9 exhibited significantly reduced PWN density and lipid peroxidation levels in cell membranes compared to the control groups, along with increased activities of peroxidase, catalase, and polyphenol oxidase. To our knowledge, this study is the first to showcase the nematocidal activity of endophytes from P. tabuliformis against PWN and their biocontrol efficacy against PWD, marking a significant advancement in the field. The findings highlight the potential of B. velezensis Pt-RP9 as a crucial biological control agent against PWD, presenting a novel and sustainable disease management approach for pine forests.

HomePlant DiseaseAhead of PrintFirst Report of Colletotrichum fructicola Causing Fruit Anthracnose on Chinese Prickly Ash (Zanthoxylum bungeanum) in China PreviousNext DISEASE NOTE OPENOpen Access licenseFirst Report of Colletotrichum fructicola Causing Fruit Anthracnose on Chinese Prickly Ash (Zanthoxylum bungeanum) in ChinaXia Yang, Lulu Lu, Yun Wang, Yan Sun, Zhaojun Geng, Bingyao Wei, Guanghui Tang, and Peiqin LiXia Yanghttps://orcid.org/0000-0002-4555-1522Key Laboratory of National Forestry and Grassland Administration on Management of Western Forest Bio-Disaster, College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, ChinaGuizhou Institute of Walnut, Guizhou Academy of Forestry, Guiyang, Guizhou 550005, China, Lulu LuKey Laboratory of National Forestry and Grassland Administration on Management of Western Forest Bio-Disaster, College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China, Yun WangKey Laboratory of National Forestry and Grassland Administration on Management of Western Forest Bio-Disaster, College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China, Yan SunKey Laboratory of National Forestry and Grassland Administration on Management of Western Forest Bio-Disaster, College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China, Zhaojun GengKey Laboratory of National Forestry and Grassland Administration on Management of Western Forest Bio-Disaster, College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China, Bingyao WeiKey Laboratory of National Forestry and Grassland Administration on Management of Western Forest Bio-Disaster, College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China, Guanghui Tang†Corresponding authors: G. H. Tang; E-mail Address: [email protected], and P. Q. Li; E-mail Address: [email protected]Key Laboratory of National Forestry and Grassland Administration on Management of Western Forest Bio-Disaster, College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China, and Peiqin Li†Corresponding authors: G. H. Tang; E-mail Address: [email protected], and P. Q. Li; E-mail Address: [email protected]Key Laboratory of National Forestry and Grassland Administration on Management of Western Forest Bio-Disaster, College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, ChinaAffiliationsAuthors and Affiliations Xia Yang1 2 Lulu Lu1 Yun Wang1 Yan Sun1 Zhaojun Geng1 Bingyao Wei1 Guanghui Tang1 † Peiqin Li1 † 1Key Laboratory of National Forestry and Grassland Administration on Management of Western Forest Bio-Disaster, College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China 2Guizhou Institute of Walnut, Guizhou Academy of Forestry, Guiyang, Guizhou 550005, China Published Online:1 Apr 2024https://doi.org/10.1094/PDIS-10-23-2125-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleChinese prickly ash (Zanthoxylum bungeanum; Rutaceae) has been cultivated in China for a long time (Sun et al. 2020). It is mostly planted in underdeveloped areas of western China to increase farmer income. However, with increased planting, a new fruit disease has emerged. This disease primarily caused fruits to prematurely turn red and fall off in a Chinese prickly ash orchard (Research Center for Engineering and Technology of Zanthoxylum, National Forestry Administration, Feng County, Shaanxi Province, 33°59′N, 106°39′E). Infected fruits have small, scattered, round to irregular black spots. The spots develop and expand as the disease progresses, forming large black patches, which we named fruit anthracnose. In June 2021, three symptomatic fruits of cv. Fengxian Dahongpao were collected in Feng County, cut into 5 × 5 mm pieces, surface sterilized for 1 min with 3% NaClO and 30 s with 75% ethanol, washed three times in sterile water, plated onto PDA plates and incubated at 25°C in the dark. Isolates Zb-Cf1 and Zb-Cf2 were selected for further analysis. Their colonies had abundant aerial mycelia on PDA and were initially white and cottony, the mycelia became light yellow to olive green over time at the edge of the front, and the reverse side became olive green. The colonies produced pale orange conidial masses after 10 days. Conidia (n = 30) were oblong with blunt ends, smooth walled, hyaline, without septa, and 3.35 to 5.48 × 8.26 to 23.85 (average 4.44 × 15.57) μm. The morphological characteristics matched descriptions of Colletotrichum fructicola (Lin et al. 2021). For molecular identification, DNA was extracted using Fungi Genomic DNA Extraction Kit (Solarbio, China). The internal transcribed spacer gene (ITS) (White et al. 1990), partial β-tubulin gene (TUB2) (O'Donnell and Cigelnik 1997), glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH) (Guerber et al. 2003), chitin synthase gene (CHS-1), and actin genes (ACT) (Carbone and Kohn 1999) were selected as conserved sequences and amplified by their primers. The PCR progress was: predenaturation at 95°C for 3 min, denaturation at 95°C for 30 s, annealing at 55°C for 20 s, and extension at 72°C for 1 min. The PCR products were sequenced by Sanger sequencing (Sangon Biotech, China). The sequences were assembled by DNAMAN and uploaded to NCBI (ITS: OQ652929 and PP060598, GAPHD: OQ702522 and PP058674, ACT: OQ702520 and PP058668), CHS-1: OQ702521 and PP058671, and TUB2: OQ702523 and PP058677). The genes were concatenated by Geneious Primer 9.0.2 and a maximum likelihood phylogenetic tree was constructed by the JC model of IQ-Tree2 version 2.2.2.6. The pathogen of fruit anthracnose of Chinese prickly ash was identified as C. fructicola based on morphology and DNA sequence analysis. The pathogenicity of Zb-Cf1 and Zb-Cf2 was tested according to Chen et al. (2017). Healthy 3-year-old Chinese prickly ash seedlings were selected for testing. From each direction of the tree (southeast, northwest, and southwest), three clusters of fruits were randomly selected, with each cluster having 10 to 20 fruits. The fruits were wounded by toothpick and spraying with conidial suspension (1 × 106 CFU/ml). Wounded healthy fruits were inoculated with sterile distilled water as a control. Each treatment included three trees. All plants were kept in a greenhouse at 25°C following inoculation. They were regularly watered and observed on a daily basis for signs of disease development. After 5 days, the plants that had been inoculated by two strains showed typical symptoms, while the control plants remained asymptomatic. To confirm pathogenicity, the same pathogen was reisolated from the infected areas of the artificially inoculated fruits, fulfilling Koch's postulates. To our knowledge, this is the first report of C. fructicola causing fruit anthracnose on Chinese prickly ash in China.The author(s) declare no conflict of interest.References:Carbone, I., and Kohn, L. M. 1999. Mycologia 91:553. https://doi.org/10.1080/00275514.1999.12061051 Crossref, ISI, Google ScholarChen, Y., et al. 2017. Plant Dis. 101:1022. https://doi.org/10.1094/PDIS-12-16-1824-RE Link, ISI, Google ScholarGuerber, J. C., et al. 2003. Mycologia 95:872. https://doi.org/10.1080/15572536.2004.11833047 Crossref, ISI, Google ScholarLin, S. R., et al. 2021. Plant Dis. 105:710. https://doi.org/10.1094/pdis-06-20-1288-pdn Link, ISI, Google ScholarO'Donnell, K., and Cigelnik, E. 1997. Mol. Phylogenet. Evol. 7:103. https://doi.org/10.1006/mpev.1996.0376 Crossref, ISI, Google ScholarSun, J., et al. 2020. J. Agric. Food Chem. 68:6403. https://doi.org/10.1021/acs.jafc.0c02026 Crossref, ISI, Google ScholarWhite, T. J., et al. 1990. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA. Crossref, Google ScholarFunding: This work was financed by General Projects of Shaanxi Provincial Key Research and Development Program (2022NY-130, and 2023-YBNY-057), Science and Technology Innovation and Achievement Transformation Project of Northwest A&F University Experimental Demonstration Station (TGZX2021-23), and Guizhou Forestry Research Project (QLKH2022-10).The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Just PublishedSubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Published: 1 Apr 2024Accepted: 19 Jan 2024 Information© 2024 The American Phytopathological SocietyFundingGeneral Projects of Shaanxi Provincial Key Research and Development ProgramGrant/Award Number: 2022NY-130Grant/Award Number: 2023-YBNY-057Science and Technology Innovation and Achievement Transformation Project of Northwest A&F University Experimental Demonstration StationGrant/Award Number: TGZX2021-23Guizhou Forestry Research ProjectGrant/Award Number: QLKH2022-10KeywordsColletotrichum fructicolafruit anthracnoseZanthoxylum bungeanumThe author(s) declare no conflict of interest.PDF download

[目的]鉴定陕西凤县花椒产区黑胫病的病原,筛选该病害的有效防治药剂,为花椒黑胫病的有效防控提供指导依据.[方法]采用组织分离法和致病性检验获得花椒黑胫病的病原菌,结合形态学特征和ITS-rDNA、COXⅡ、TEF1-α和β-tubulin序列分析对病原菌进行鉴定;采用菌落生长速率法测定了15 种杀菌剂对花椒黑胫病菌的室内毒力.[结果]从花椒黑胫病组织中分离纯化到4株菌落形态不同的菌株,经柯赫氏法则验证,明确菌株Zb-P1 为花椒黑胫病的病原菌;基于Zb-P1 菌落形态和繁殖体显微结构特征观察,发现Zb-P1 菌落呈花瓣状,菌丝无隔膜,无性繁殖时产生典型的柠檬状游动孢子囊,故将Zb-P1鉴定为疫霉属Phytophthora菌物;通过对Zb-P1 的ITS、COXⅡ、TEF1-α和β-tubulin序列分析,将Zb-P1 鉴定为柑橘褐腐疫霉P.citrophthora.复配化学杀菌剂40%烯酰·氰霜唑悬浮剂、68.75%氟菌·霜霉威悬浮剂、2%霜脲·锰锌可湿性粉剂和78%烯酰·吡唑酯水分散粒剂对花椒黑胫病的室内毒力较强,其EC50 值分别为 0.390 1、0.385 6、0.216 6 和 0.182 0 mg·L-1;生物源杀菌剂 5%香芹酚可溶液剂、0.4%蛇床子素可溶液剂、0.5%小檗碱水剂和 0.3%苦参碱乳油对花椒黑胫病的室内毒力较差,EC50 均值分别为 13.246 7、9.411 7、8.244 3 和 8.231 5 mg·L-1.[结论]引起陕西凤县花椒黑胫病的病原菌为柑橘褐腐疫霉P.citrophthora,对花椒黑胫病菌抑菌作用显著的杀菌剂为烯酰·氰霜唑、氟菌·霜霉威、霜脲·锰锌和烯酰·吡唑酯.

根际微生物是土壤生态系统的重要组成部分,明确植物根际土壤微生物的群落结构及影响因素对农林生态系统的可持续发展具有重要的意义.结合高通量测序技术及土壤理化性质测定,分析不同林龄花椒根际土壤理化性质的变化与微生物的群落结构差异.结果表明,随着林龄增加,花椒根际土壤呈现弱酸化,土壤养分整体表现出先增加而后降低的趋势,以8 a林龄根际土的养分最高;花椒根际土中含真菌OTU 1229个,归属于12门、35纲、78目、149科、321属和466种;细菌OTU 1298个,归属于22门、49纲、71目、163科和277属.Alpha多样性分析发现,林龄对花椒根际土壤真菌的物种丰富度和多样性影响显著,以8 a林龄的物种丰富度和多样性最高,15 a林龄的次之,3 a林龄的最低;而林龄对花椒根际土壤细菌的物种丰富度和多样性影响不显著.在3个不同林龄的花椒根际土壤中,优势真菌门均为子囊菌门(Ascomycota)和罗兹菌门(Rozellomy-cota),优势属均为缘刺盘菌属(Cheilymenia)和镰孢菌属(Fusarium);优势细菌门为变形菌门(Proteobacteria)和酸杆菌门(Acidobacteria),优势属为鞘氨醇单胞菌属(Sphingomonas)、酸杆菌门Gp6和Gp4群组和芽单胞菌属(Gemmatimonas);且发现不同林龄花椒根际土壤微生物的群落结构分离明显,说明林龄是微生物群落结构的主要影响因子.与花椒根际土壤微生物的Alpha多样性显著相关的土壤理化因子为pH、有机质、速效磷和速效钾,而影响花椒根际土壤微生物群落结构的重要土壤理化因子为有机质、总氮和pH.研究不仅阐明了林龄对花椒根际土壤理化性质与微生物群落结构的影响,还揭示了土壤理化性质与花椒根际土壤微生物群落结构之间的关系,不仅能为椒园土壤质量变化的动态监测提供依据,还能为花椒根际土壤微生物资源的功能开发奠定基础.

近几年,根腐病在我国花椒产区大面积发生,严重影响了花椒的产量和质量.为明确引起花椒根腐病的病原,本研究从陕西省凤县花椒示范基地采集花椒根腐病标本,采用组织分离法和致病性检验获得花椒根腐病菌.通过对花椒根腐病菌的形态学观察及ITS、β-tubulin和TEF1-a序列分析,将花椒根腐病菌鉴定为腐皮镰刀菌(Fusarium solani).杀菌剂室内抑菌活性筛选结果表明,选用的十种杀菌剂对F.solani的菌落生长均表现出一定的抑制作用,其中以6％丙唑·多菌灵悬乳剂、30％苯甲·丙环唑悬乳剂、50％多菌灵可湿性粉剂和80％代森锰锌可湿性粉剂对花椒根腐病菌的抑制作用较强,EC50值分别为0.48、0.66、1.40和1.61 mg-L-1.本研究结果为花椒根腐病的有效防控提供了科学依据.

干腐病是花椒Zanthoxylum bungeanum种植中的重大病害,为了开发防治花椒干腐病的绿色生物农药,采用菌落生长速率法和显微观察法检测壳寡糖对花椒干腐病菌Fusarium zanthoxyli的菌落生长、孢子活力和孢子萌发的影响,并检测壳寡糖对花椒盆栽苗干腐病的防治效果.结果表明:壳寡糖对干腐病菌菌落生长的抑制率随质量浓度增加而增加,最适施用质量浓度为0.4～0.6 mg/mL,菌落生长抑制率可达65％以上;0.7 mg/mL的壳寡糖溶液与孢子共培养24 h时,孢子死亡率可达100％;孢子萌发率随壳寡糖质量浓度的升高而降低,芽管生长长度显著缩短,当使用0.5 mg/mL壳寡糖溶液处理孢子12 h时,对孢子萌发的抑制率可达100％;当壳寡糖的施用质量浓度为0.5 mg/mL,对花椒盆栽苗干腐病防治效果可达65.02％.壳寡糖能显著地抑制花椒干腐病菌的菌落生长,降低病菌孢子活力和萌发能力,并能减轻花椒盆栽苗干腐病的发生,可为壳寡糖在花椒干腐病的田间防治应用中提供依据.

[目的]明确黄帝陵侧柏叶枯病的病原菌及其培养特性,筛选对该病害具有较好防治效果的药剂,为黄帝陵古柏群的保护提供指导.[方法]采用组织分离培养法从采集的侧柏叶枯病叶中分离病菌,通过回接试验和柯赫氏法则,证明分离物是否为引起侧柏叶枯病的病原菌;通过形态学和分子生物学对黄帝陵侧柏叶枯病病原菌进行鉴定,并研究其在不同培养基上的生长速率;采用带毒平板法和田间试验筛选对黄帝陵侧柏叶枯病具有较好防治效果的药剂.[结果]经形态学和分子生物学鉴定,黄帝陵侧柏叶枯病病原菌为互隔交链孢(Alternariaalternata)和芍药生拟盘多毛孢(Pestalotiopsispaeoniicola),这2种病原菌可单独侵染,也可共同复合侵染.互隔交链孢和芍药生拟盘多毛孢在黄豆(SA)培养基和马铃薯蔗糖琼脂(PSA)培养基上生长速率均较高.室内抑菌活性测定结果表明,戊唑醇对互隔交链孢和芍药生拟盘多毛孢抑菌活性较高,其有效中浓度(EC50)分别为1.13和1.38 mg/L;咪鲜胺次之,其EC50分别为1.58和1.44 mg/L.田间试验结果表明,80％戊唑醇可湿性粉剂750倍液和25％咪鲜胺乳油3 000倍液对侧柏叶枯病的防效最佳,喷药4次后其防治效果均在80％以上.[结论]黄帝陵侧柏叶枯病由互隔交链孢(A.alternata)和芍药生拟盘多毛孢(P.paeoniicola)单独或共同侵染引起,为弱寄生菌,这2种病原菌均在SA和PSA培养基生长良好;侧柏为芍药生拟盘多毛孢(P.paeoniicola)的新寄主;戊唑醇和咪鲜胺对黄帝陵侧柏叶枯病具有良好的防治效果.

Stem canker of Zanthoxylum bungeanum is a devastating disease that seriously affects the plantation and industrial development of Z. bungeanum due to a lack of effective control measures. The objective of this study was to screen out resistant Z. bungeanum varieties and further explore their resistance mechanisms against stem canker. Results showed that the most resistant and susceptible varieties were, respectively, Doujiao (DJ) and Fengxian Dahongpao (FD). Combining transcriptomic and metabolomic analyses, we found that the genes and metabolites associated with the phenylpropanoid metabolism, especially flavonoid biosynthesis, were highly significantly enriched in DJ following pathogen infection compared with that in FD, which indicated that the flavonoid metabolism may positively dominate the resistance of Z. bungeanum. This finding was further confirmed by quantitative real-time polymerase chain reaction analysis, through which higher expression levels of core genes involved in flavonoid metabolism in resistant variety were observed. Moreover, by analyzing the differences in the flavonoid content in the stems of resistant and susceptible varieties and the antifungal activities of flavonoids extracted from Z. bungeanum stems, the conclusion that flavonoid metabolism positively regulates the resistance of Z. bungeanum was further supported. Our results not only aid in better understanding the resistance mechanisms of Z. bungeanum against stem canker but also promote the breeding and utilization of resistant varieties.

《微生物学》是林学院森林保护专业的一门核心专业基础必修课,与人类日常生活和林业生产密切相关.为了有效发挥课堂育人主渠道作用,将课程思政理念融入《微生物学》,文章从教学内容中思政元素的挖掘、课程思政教育的实现途径和举措、课程思政注意事项等几方面提出一些自己的看法和观点,旨在提高《微生物学》课堂教学的育人效果,并为其他自然科学课程的课程思政提供借鉴和参考.

为了提高高校办学水平,培养具有国际竞争力的高水平专业技术人才,各高等院校已陆续开展专业课的全英文教学.《微生物学》是农林院校一门重要的专业基础课,文章在教学实践的基础上,结合林学院森林保护学专业的特点,对《微生物学》全英文课程进行了教学模式与教学方法等方面的初步探索,总结了一些经验和体会,分析了一些存在的问题,并提出了一些建议,以期为《微生物学》全英文教学质量的提高提供参考.

In this study, two respective groups of RNA aptamers have been selected against two main classes of glycosaminoglycans (GAGs), heparosan, and chondroitin, as they have proven difficult to specifically detect in biological samples. GAGs are linear, anionic, polydisperse polysaccharides found ubiquitously in nature, yet their detection remains problematic. GAGs comprised repeating disaccharide units, consisting of uronic acid and hexosamine residues that are often also sulfated at various positions. Monoclonal antibodies are frequently used in biology and medicine to recognize various biological analytes with high affinity and specificity. However, GAGs are conserved across the whole animal phylogenic tree and are nonimmunogenic in hosts traditionally used for natural antibody generation. Thus, it has been challenging to obtain high affinity, selective antibodies that recognize various GAGs. In the absence of anti-GAG antibodies, glycobiologists have relied on the use of specific enzymes to convert GAGs to oligosaccharides for analysis by mass spectrometry. Unfortunately, while these methods are sensitive, they can be labor-intensive and cannot be used for in situ detection of intact GAGs in cells and tissues. Aptamers are single-stranded oligonucleotide (DNA or RNA) ligands capable of high selectivity and high affinity detection of biological analytes. Aptamers can be developed in vitro by the systematic evolution of ligands by exponential enrichment (SELEX) to recognize nonimmunogenic targets, including neutral carbohydrates. This study utilizes the SELEX method to generate RNA aptamers, which specifically bind to the unmodified GAGs, heparosan, and chondroitin. Binding confirmation and cross-screening with other GAGs were performed using confocal microscopy to afford three specific GAGs to each target. Affinity constant of each RNA aptamer was obtained by fluorescent output after interaction with the respective GAG target immobilized on plates; the K D values were determined to be 0.71-1.0 μM for all aptamers. Upon the success of chemical modification (to stabilize RNA aptamers in actual biological systems) and fluorescent tagging (to only visualize RNA aptamers) of these aptamers, they would be able to serve as a specific detection reagent of these important GAGs in biological samples.