卵菌引起的病害对农业生产危害严重,是农林业重点研究和防控对象。为探索卵菌研究现状和发展态势,本研究以Web of Science为数据源,对1985—2023年收录的卵菌相关文献进行计量学分析,并利用CiteSpace绘制知识图谱对结果进行可视化展示。发文量统计分析显示,美、中、德等国家在卵菌研究中占主导地位,近5年中国发文量呈快速增长态势,并于2022年跃居全球第一;在研究机构排名中,美国农业部、南京农业大学和加州大学系统的发文量位列前三,且研究成果具有较高影响力。进一步对研究热点进行分析,该领域被关注的主要病菌包括腐霉属(Pythium spp.)、致病疫霉(Phytophthora infestans)、辣椒疫霉(Ph. capsici)等10种常见致病卵菌,研究内容主要包括系统获得抗性、气候变化、抗菌活性等。文献共被引聚类分析表明,卵菌领域已逐步形成以RXLR效应蛋白、趋同进化、毒力因子等为代表的重要研究方向。此外,高被引文献分类分析揭示了效应子致病机制、病害防治方法、生物防治、免疫信号调控等正受到高度关注。这些工作有利于新的卵菌研究者快速了解该领域的研究现状和前沿热点,同时对预判卵菌潜在的研究方向提供一定的参考。

Viral diseases in cucumber in Qudi are more and more serious in recent years. To detect and identify the main viruses, the plant samples of cucumber were collected from Qudi town, Jiyang district, and next-gene-ration sequencing technology (NGS), RT-PCR amplification and analysis of viral genome sequences were carried out. The results showed that the viruses infecting cucumber in the spring were cucumber green mottle mosaic virus (CGMMV) and watermelon silver mottle virus (WSMoV). Besides CGMMV and WSMoV, cucumber plants in the autumn were also infected with zucchini yellow mosaic virus (ZYMV). The detection rates of CGMMV, WSMoV and ZYMV by RT-PCR were 68.2%, 45.5% and 50.0%, respectively, and the detection rate of complex infection was 50%. Genetic sequence analysis revealed that the coat protein (CP) gene sequence of CGMMV [JY2-6 (GenBank accession number: OR591512) isolated in this study was similar to the sequence of CGMMV [SDRZ (GenBank accession number: KX185151)] isolated from cucumber in Rizhao, and the identity was 100%. The nucleocapsid (N) gene sequence of WSMoV [JY2-4 (GenBank accession number: OR591517) isolated in this study was similar to the sequence of WSMoV [W6412 (GenBank accession number: AM113765)] isolated from watermelon in Thailand, and the identity was 99.1%. The CP gene sequence of ZYMV [JY2-7 (GenBank accession number: OR591522) isolated in this study was similar to the sequence of ZYMV [Yaz.Ashk.S.Z (GenBank accession number: KX495623)] isolated from cucumber in Iran, and the identity was 97%. This study demonstrated that the cucumber in Qudi was mainly infected by CGMMV, WSMoV and ZYMV, and complex infection was also common. This study provided a basis for virus prevention of cucumber in Qudi.

甘蔗镰孢菌(Fusarium sacchari)是引致甘蔗梢腐病的主要病原真菌之一。为明确F. sacchari中金属蛋白酶(metalloproteinase)类效应蛋白的功能,本研究前期利用F. sacchari基因组数据对其具有分泌性的金属蛋白酶基因进行预测,从中扩增得到一个锌依赖型金属蛋白酶类效应蛋白基因Fs03538,并对其功能进行了初步研究。结果显示:Fs03538含有一个典型的锌依赖型金属蛋白酶结构域(ZnMc super family),蛋白质N端的1-18个氨基酸序列含有特定的分泌信号序列,亚细胞定位显示Fs03538能够定位于植物细胞核中;qRT-PCR分析表明Fs03538在甘蔗镰孢菌侵染甘蔗12 h到达最高峰值,之后表达量持续维持在较高水平;根癌农杆菌(Agrobacterium tumefaciens)介导的烟草瞬时表达系统确定Fs03538可以抑制小鼠促凋亡蛋白BAX引起的烟草细胞坏死,在F. sacchari中敲除Fs03538后发现突变体在生长速度、产孢量与野生型无明显差异,但致病力显著下降。以上结果表明,Fs03538在F. sacchari入侵寄主的过程中高量表达,可能通过进入寄主细胞核中抑制寄主免疫响应,是F. sacchari重要的毒力因子。

茄腐镰孢菌(Fusarium solani)寄主范围广泛,可引发生产上的毁灭性病害—根腐病。分泌蛋白在病原菌对植物的侵入、定殖和扩展等致病过程中起着重要作用,本研究利用SignalP、TMHMM、WoLF PSORT和PredGPI等软件对F. solani全基因组编码的17654条蛋白序列进行了分泌蛋白和效应子的预测分析,结果表明:F. solani基因组中有1032个分泌蛋白基因,占编码蛋白基因总数的5.85%。进一步利用dbCAN3等软件对经典分泌蛋白中的碳水化合物活性酶 (Carbohydrate-active enzymes, CAZymes) 进行预测,发现其中258个为CAZymes,以糖苷水解酶亚家族成员最多。分泌蛋白中效应蛋白(effector)的预测结果表明,F. solani中有185个潜在的效应蛋白,其中183个蛋白的功能可被PHI数据库注释到。利用农杆菌介导的植物瞬时表达系统,在本氏烟中对其中5个注释为增加F. solani毒力的效应蛋白进行验证,发现其中2个候选效应蛋白(XP_046140852.1 和XP_046131041.1)能够抑制由Bcl2关联X蛋白BAX (BCL2-associated X protein) 引起的细胞程序性死亡,可能在F. solani侵染致病过程中起重要作用。研究结果有助于揭示F. solani的致病分子机制,同时为F. solani与植物互作的深入研究提供了理论依据。

水稻是世界上重要的粮食作物。虽然针对水稻上为害严重的稻瘟病和白叶枯病,目前已克隆并鉴定了一些抗病基因,但相应的抗病资源依旧匮乏。本研究发现乙烯途径转录因子OsEIL4参与调控水稻对稻瘟病和白叶枯病的抗性反应。通过实时荧光定量PCR(quantitative real-time PCR, qPCR)检测发现OsEIL4基因在稻瘟菌(Magnaporthe oryzae)和白叶枯菌(Xanthomonas oryzae pv. oryzae)侵染时均诱导表达。所构建OsEIL4转基因水稻植株的抗病性分析结果显示,相比于野生型材料,OsEIL4基因编辑(OsEIL4敲除)和基因沉默水稻植株对这两种病原菌的抗性减弱,而OsEIL4过表达植株对二者的抗性增强。此外,qPCR检测发现,乙烯信号通路标记基因和防御基因OsPR1a和OsPR5在OsEIL4基因编辑稻株中下调表达,而在OsEIL4过表达稻株中上调表达,表明OsEIL4作为乙烯途径的正调控因子可通过调控防御基因表达介导水稻抗病性。亚细胞定位和酵母单杂交结果表明OsEIL4具有转录因子的特性,预示其可能通过行使转录调控功能参与水稻免疫反应。本研究挖掘到了一个具有广谱抗性的基因资源,将为水稻抗病分子育种提供新思路。

为了阐明灰葡萄孢(Botrytis cinerea)蛋白质-蛋白质之间的互作关系,深入探究B. cinerea致病的分子机理,本研究使用同源映射(Interolog)方法,构建了一个包含2 296个蛋白和9 376对互作的B. cinerea蛋白质-蛋白质互作网络(PPI)图谱;并使用结构域-结构域相互作用(Domain-domain interactions)方法,对构建的B. cinerea蛋白质-蛋白质互作网络图谱进行了进一步的筛选和优化,构建了一个包含1 233个蛋白和2 585对互作的高可信度的蛋白质-蛋白质互作网络,利用MCODE算法将该网络图划分为27个功能模块,并对已知致病相关蛋白GB1、RAS2、BMP1和BMP3的互作蛋白子网络进行了分析;利用酵母双杂交技术对该蛋白质互作网络中BofuT4_P103090与BofuT4_P056160和BofuT4_P007800蛋白之间的互作关系进行验证,确定了BofuT4_P103090与BofuT4_P056160和BofuT4_P007800蛋白存在互作关系,验证了本研究所构建的蛋白质-蛋白质互作网络的可靠性。研究结果为阐明B. cinerea致病分子机理研究奠定基础,并为其他物种的蛋白质-蛋白质互作网络及其致病机理研究提供参考。

群结腐霉(Pythium myriotylum)是一种植物病原卵菌,可侵染大豆、番茄、小麦等多种重要经济、粮食作物,引起根腐、茎基腐病,造成严重危害。本研究报道一个来源于P. myriotylum的碳酸酐酶家族蛋白(Carb anhydrase)-PmCA1,发现其在P. myriotylum侵染植物过程中上调表达,同时其可抑制flg22诱导的活性氧迸发及防御相关基因表达,促进辣椒疫霉(Phytophthora capsici)的侵染。以上结果表明PmCA1可能是P. myriotylum的毒性因子,通过抑制植物PTI免疫反应来促进病原菌侵染定殖。研究结果将为P. myriotylum分泌蛋白的功能研究提供思路,为探究P. myriotylum的致病机制提供理论支撑。

苹果再植病是土壤微生态失衡造成的典型病害,调控土壤微生物群落,培育抑病土壤是有效防控该病的关键。为明确抑病土中起关键防控作用的微生物群体的种类及作用机理,本研究比较了7种不同类型的土壤生物调控措施对苹果砧木八棱海棠(Malus micromalus)生长、土壤理化性质、根际土壤微生物多样性的季节性动态变化的影响,结果表明:这7种措施均提高了苹果再植土壤中主要养分的含量和酶活性,增加了土壤微生物的多样性,促进了抑病土壤的形成。在门水平上,抑病土壤优势细菌包括变形菌门和酸杆菌门,优势真菌有子囊菌门和担子菌门;在属水平上,细菌以MND1、Nitrospira和Sphingomonas为主,而Fusarium、Ilyonectria和Alternaria等潜在病原真菌的相对含量降低。相关性分析表明,抑病土壤中硝化螺旋菌(Nitrospira)、木霉菌(Trichoderma)等55属为关键优势微生物,以Nitrospira为抑病土壤微生物互作调控的核心;其中,32属根际细菌分为3个功能群,通过土壤全局概览通路、碳水化合物代谢和氨基酸代谢等功能与土壤氮磷等营养元素转换呈极显著正相关,共生和腐生营养型类群等23属真菌与土壤有机质以及蔗糖酶、脲酶、碱基磷酸酶和过氧化氢酶活性呈正相关。关键土壤抑病微生物组通过拮抗病原菌、激活植物免疫、产生特殊代谢产物等促进植物生长以及抑制病害的发生。

黄瓜猝倒病是黄瓜苗期主要土传病害之一,随着设施黄瓜栽培面积的扩大,猝倒病的发生与危害在逐年加重。本研究从杭州地区茄子种植地的健康茄子植株根际土壤中分离筛选获得一株细菌ZF514,通过二分皿平板对峙法发现其挥发性物质对瓜果腐霉菌(Pythium aphanidermatum)有显著的拮抗效果。根据形态特征、生理生化特性,以及基于多基因(16S rDNA、gyrA和rpoB)的系统发育分析结果,确定ZF514菌株为贝莱斯芽胞杆菌(Bacillus velezensis)。ZF514菌株对多种病原真菌具有明显的拮抗作用。进一步将模拟微生物熏蒸处理的土壤用于盆栽试验,结果显示,盆栽所用土壤经ZF514菌株熏蒸处理后可显著降低黄瓜猝倒病的发生率,防效达63.69%。综上所述,产抑菌性挥发物质的B. velezensis ZF514菌株在微生物熏蒸防治土传病害方面具有一定的开发潜力。

由芸薹根肿菌(Plasmodiophora brassicae)侵染引起的根肿病是严重威胁十字花科蔬菜生产的一种病害,筛选具有应用价值和开发潜力的生防菌对于该病害的绿色防控具有重要意义。本研究从根肿病发生的重病田中健康白菜的根组织中分离内生细菌,以辣椒疫霉(Phytophthora capsici)为指示菌,利用平板对峙和温室盆栽试验筛选出1株对白菜根肿病具有生防效果的菌株,命名为JP2。结合形态学特征、生理生化特性以及16S rDNA基因序列分析,将JP2菌株鉴定为油菜假单胞菌(Pseudomonas brassicacearum)。JP2菌株培养48 h后的发酵液中几丁质酶活为0.034 U·mL^-1,纤维素分解能力H值为1.89,铁载体相对活性为57.24%。JP2菌株编码荧光嗜铁素(PVD)和2, 4-二乙酰间苯三酚(DAPG)合成基因。此外,该菌株对6种常见的病原真菌均有较好的抑制作用,抑菌谱较广,其粗提物对P. brassicae休眠孢子也有较好的致死效果,致死率达44.44%。JP2接种30 d时,其在白菜根际土中的定殖密度仍稳定在3.03×10² CFU·g^-1,能够显著降低土壤中P. brassicae休眠孢子的数量,对白菜根肿病的盆栽防效为58.83%。表明JP2菌株对白菜根肿病具有较好的生防潜力。

为进一步明确广藿香酮农用抑菌活性,本研究用一步法合成了广藿香酮,通过¹H和¹³C NMR、HRMS和X射线单晶衍射确证了其结构,并测定了其对常见植物病原菌的活性。离体活性结果表明,广藿香酮对油菜菌核病菌、立枯丝核菌和固执腐霉的菌丝生长抑制效果较为显著,EC₅₀值分别为5.32、5.53和7.83 μg·mL^-1,均优于对照药剂香芹酚。室内药效结果表明,广藿香酮在200 μg·mL^-1下对油菜菌核病的离体叶片保护作用药效为97.9%,与对照药剂啶酰菌胺15 μg·mL^-1(99.0%)和香芹酚1 000 μg·mL^-1(99.7%)下的效果相当。盆栽试验结果表明,广藿香酮在500 μg·mL^-1下对大豆立枯病和烟草猝倒病的保护作用防效分别为94.6%和91.8%,与香芹酚1 000 μg·mL^-1下效果相当(93.1%和91.2%);在100 μg·mL^-1下对小麦白粉病的保护作用防效为94.1%,与50 μg·mL^-1下多菌灵(93.5%)和500 μg·mL^-1下香芹酚(93.0%)的防效相当。本研究为广藿香酮在植物源杀菌剂中的开发和利用提供参考。

咯菌腈是目前生产上防控由灰葡萄孢(Botrytis cinerea)引起的蔬菜灰霉病的主要药剂。为了明确山西省B. cinerea对咯菌腈产生抗药性的情况,本文采用菌丝生长速率法测定了来自山西各地312个B. cinerea菌株对咯菌腈的抗性水平,并对抗性菌株Bos1基因的突变位点、生物学性状,以及与其它杀菌剂的交互抗性进行了研究。结果表明:供试菌株对咯菌腈的抗性频率为7.37%,抗性水平主要为低、中抗,仅检测到2个高抗菌株;所有咯菌腈抗性菌株Bos1基因均发生了突变,突变发生区域包括TAR、HAMP和REC结构域,抗性类型包括F127S、V287G、I365N、I365S、Q369P+N373S、V1136I和A1259T;抗性菌株在菌丝生长、产菌核能力、产孢量和致病力方面均低于敏感菌株,生物适合度下降;咯菌腈与吡唑醚菌酯、苯醚甲环唑、嘧霉胺、咪鲜胺4种作用机制不同的杀菌剂之间均不存在交互抗性,因此可通过药剂轮换和复配使用来防治灰霉病。本研究为蔬菜灰霉病化学防治的科学、合理用药提供了理论依据。

人参链格孢(Alternaria panax)是人参黑斑病的主要致病菌之一,可侵染人参地上部的叶片、茎秆和果实,引起叶枯、茎秆坏死及果实干瘪,对人参产量及品质影响很大。本研究以人参链格孢为研究对象,建立根癌农杆菌介导的遗传转化方法。为了进一步验证遗传转化体系的可行性,对人参链格孢赖氨酸合成相关基因ApLYS2进行了敲除。结果表明,当共培养时间为48 h,共培养温度为22 ℃,农杆菌菌液浓度OD₆₀₀为0.6,原生质体浓度为10⁶个·mL^-1时,转化效率最高,转化率约为23个/10⁶个·mL^-1,潮霉素抗性基因成功转入人参链格孢中;采用本研究所构建的遗传转化方法,成功实现了赖氨酸合成相关基因ApLYS2的敲除。所获得的基因缺失突变体ΔAplys2-4和ΔAplys2-7无法在缺乏赖氨酸的培养基上生长,外源添加赖氨酸突变体生长得到恢复。本研究成功构建了农杆菌介导的人参链格孢遗传转化体系并以赖氨酸合成相关基因ApLYS2的成功敲除进行了验证,为其致病机制研究提供了有效的技术手段。

In this study, the fungal strain LD-11 was isolated from the infected plant of Lonicera caerulea (cv Lanjingling) collected in the horticulture experimental station of Northeast Agricultural University, Harbin, Heilongjiang Province. The strain was identified as Epicoccum nigrum by morphology, rDNA-ITS, LSU, TUB, RPB2 gene sequence amplification and phylogenetic tree construction. The experimental results showed that E. nigrum LD-11 could grow on PDA, OA and MEA medium. The optimal culture medium was OA, and the optimal culture conditions were growth temperature of 25 ℃, pH 6, carbon source is starch and nitrogen source is yeast extract, and full light conditions were conducive to mycelial growth. This study is the first time to isolate and identify E. nigrum, the pathogen of leaf spot disease in L. caerulea, which will provide an important source of pathogenic fungi for future research on control of plant disease.

Polygonatum kingianum Coll. et Hemsl., a perennial herbaceous plant belonging to the family Liliaceae, has special medicinal and dietary values. Rhizome rot, usually leading to the decrease of yield and quality, is a frequently occurred disease on P. kingianum in Yunnan Province. In this study, diseased P. kingianum samples with typical symptoms of rhizome rot were collected, and a representative fungal strain 19-1 was obtained by tissue isolation and single spore purification. The pathogenicity of strain 19-1 to P. kingianum was tested and confirmed by irrigating inoculation of plant seedlings with spore suspension (1×10⁶ spores·mL^-1). According to morphological characteristics and multigene-based phylogenetic analysis results, strain 19-1 was identified as Fusarium concentricum. This is the first report of F. concentricum causing rhizome rot on P. kingianum. Our results provide a theoretical basis for further investigation of the epidemiology and integrated control of the disease.

Pittosporum tobira is used as a evergreen plant in urban landscape. In recent years, a serious leaf disease was found on P. tobira in Chongqing, which seriously affected the ecological and landscape benefits. Disease incidence ranged from 20% to 50% in the affected fields. In this study, the pathogens of this disease were isolated and verified by Koch’s rule. The strain were identified as Colletotrichum fioriniae based on morphological characteristics and rDNA-internal transcribed space(ITS)、actin(ACT)、β-tubulin(TUB2) and glyceraldehyde-3-phosphate dehydrogenase(GAPDH) gene sequence analysis. The identification of the pathogen of anthracnose in P. tobira will provide theoretical basis for further study of disease monitoring and control.

Avena sativa is an important crop for food and feed in the world. During the investigation of oat diseases in Hohhot in 2022, a new disease was found which produced long spindle-shaped necrotic lesions on oat sheath with black spots in the center. More strains with the same colony morphology were generated from the diseased sheath tissues. One representative strain QSH2-3-2 was selected for pathogenicity test. The results show that strain QSH2-3-2 can cause necrotic spots on oat leaves and sheaths. It was identified as Didymella glomerata by morphological characteristics and multi-locus DNA sequence analysis. To our knowledge, this is the first report that D. glomerata was the pathogen of oat spot blight.

Grapevine (Vitis vinifera L.), is known as the first of the world’s four fruits, both fruit and medicinal value. Recently, ‘shine muscat’ and ‘Christmas Rose’ were premium varieties of grapevine. From May 2022 to May 2023, a fruit drop and rot disease was found on grapevine in Zhaoqin city, Guangdong province. To clarify the reason of this phenomenon, the pathogen was isolated and purified by tissue separation method, and its pathogenicity was confirmed based on the Koch’s postulates. According to morphological features and phylogenetic analysis of rDNA-ITS and EF-1α gene, the pathogen was identified as Aspergillus aculeatus. To our knowledge, this is the first report of A. aculeatus causing fruit rot on grapevine in China. The results will provide scientific basis for effective control of the disease on grapevine.

In 2023, a typical sample of root rot of Idesia polycarpa was collected in Zunyi city, Guizhou Pro-vince, China, and the pathogenic strain was obtained by tissue separation method. According to Koch’s rule, pathogenicity test, morphological characteristics and ITS, TEF1-α and TUB multigene phylogenetic analysis, the pathogen was identified as Fusarium solani. The results provided a theoretical basis for the field control of the root rot of Idesia polycarpa. This is the first time to report the root rot of I. polycarpa induced by F. solani in China.

Xinjiang wild apricot (Prunus armeniaca) has strong resistance to drought and cold. It is an important genetic resource for breeding. In 2021, twenty leaf samples of Xinjiang wild apricot were collected in the wild forests of Tianshan Mountain in YiLi, Xinjiang. Using high-throughput sequencing and RT-PCR, peach chlorotic leaf spot virus (PCLSV) and mume-associated luteovirus (MaLV) were identified. Whole genomes of these two viruses were obtained by RT-PCR and RACE. After removing poly (A), the genome of PCLSV from Prunus armeniaca (PCLSV-YX) contains 7 462 nucleotides (nts) with three overlapping open reading frames (ORFs). The genome of MaLV from Prunus armeniaca (MaLV-YX) contains 5 753 nts, and has six ORFs. Phylogenetic analysis showed that PCLSV-YX was closely related to isolates of ‘PR19-2’ and ‘TaTao’. MaLV-YX was closely related to cherry-associated luteovirus (ChALV), prunus mahaleb-associated luteovirus (PmALV), peach-associated luteovirus (PaLV) and peach-associated luteovirus 2 (PaLV2).

大豆是重要的粮油作物,人类优质植物蛋白的来源。我国自2019年起实施“大豆振兴计划”,以扩大大豆种植面积,提升单产水平,应对复杂多变的国际贸易环境。大豆疫霉(Phytophthora sojae)等病原菌引起的大豆根腐病是严重制约大豆产量和质量提升的因素之一。本文综述了大豆疫霉及与其复合侵染引起大豆根腐病的其他病原菌种类、危害症状,以及大豆疫霉根腐病在全球大豆主产区的发生现状和综合防治的相关研究进展,探讨了目前大豆疫霉根腐病防治过程中存在的问题及未来的发展方向,以期为该病害的科学监测和综合防控提供重要参考。

桃枝枯病主要由桃间座壳菌(Diaporthe amygdali, 无性态为Phomopsis amygdali)侵染引发,是我国南方各桃主产区最重要的真菌病害之一。该病害严重制约了我国南方桃产业发展,给桃农带来了巨大的经济损失。本文综述了桃枝枯病的发生历史、分布及危害、病原及生物学特性、病害循环和发病规律、病害检测、综合防控等方面的研究进展,对潜在问题进行了分析,并对未来研究方向进行了展望,以期为该病害的深入研究提供参考。

番茄褐色皱纹果病毒(tomato brown rugose fruit virus,ToBRFV)近年来在全球番茄产区快速发生蔓延,造成严重的经济损失。云南建水番茄上出现疑似ToBRFV感染的症状,并对周边番茄产区产生危害。本研究对云南建水田间疑似ToBRFV感染的番茄果实样品进行电子显微镜观察及RT-PCR检测鉴定,并进一步对分离株进行全基因组测序分析,构建系统进化树分析其与其它ToBRFV分离株的进化关系。结果表明,从感病的番茄果实上发现杆状病毒粒体,大小约18 nm×300 nm,具有烟草花叶病毒属病毒的典型形态特征;用ToBRFV特异性检测引物进行RT-PCR扩增得到591 bp目的片段,经NCBI blast比对,与ToBRFV具有最高一致率(达99%以上),将该分离株命名为ToBRFV-2022-JS(GenBank登录号:OR593752)。测序发现ToBRFV-2022-JS基因组全长6 386 nt,具有4个ORFs,分别编码126 kDa和183 kDa复制酶,30 kDa运动蛋白MP和17.5 kDa外壳蛋白CP。进化树分析显示该分离株与ToBRFV银川分离株(GenBank登录号:OR500698.1)的亲缘关系最近,核苷酸序列一致率为99.73%。上述结果表明云南建水番茄果实受到ToBRFV感染。该结果为ToBRFV在云南番茄产区的监测与防控提供了依据。

以分别单独感染甘薯褪绿矮化病毒(sweet potato chlorotic stunt virus,SPCSV)和甘薯羽状斑驳病毒 (sweet potato feathery mottle virus,SPFMV)以及复合感染两种病毒的甘薯植株为材料,研究了SPCSV和SPFMV协生对甘薯光合作用等生理特征以及叶片表皮亚显微结构、叶绿体超微结构等细胞病理学变化的影响。结果表明,SPCSV和SPFMV复合侵染显著降低了净光合速率(A)、气孔导度(Gs)、蒸腾速率(E)、CO₂利用效率(CUE)和叶绿素(ChI)含量;提高了甘薯叶片超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)、多酚氧化酶(PPO)和苯丙氨酸解氨酶(PAL)的活性及丙二醛(MDA)含量。扫描电镜观察结果显示,与健康对照相比,SPFMV和SPCSV单侵染时甘薯叶片表皮细胞和气孔无明显变化,而两种病毒的复合侵染可引起甘薯叶片外表皮气孔关闭,叶片表面凹陷,保卫细胞萎缩。透射电镜观察发现,与健康对照相比,SPFMV和SPCSV单独侵染时叶绿体数量没有明显变化,但对其超微结构有一定影响,包括淀粉粒增多,体积膨大、部分基质和基粒片层排列疏松;当SPCSV和SPFMV复合侵染则可导致叶绿体数量明显减少,叶绿体内部结构和膜遭到严重破坏,细胞质中发现大量风轮状内含体。

灰葡萄孢(Botrytis cinerea)是一种寄主范围广泛的死体营养型植物病原真菌,可在多种重要农作物上引发灰霉病。灰葡萄孢通过分泌大量的细胞死亡诱导蛋白(CDIPs)诱发寄主细胞死亡,从而促进其侵染。本研究通过对灰葡萄孢侵染阶段的分泌蛋白组进行分析,筛选到一个分泌蛋白BcXYG3。BcXYG3含有GH12和fCBD结构域,在本氏烟草叶片中瞬时表达BcXYG3可诱导叶片细胞死亡,而瞬时表达去掉信号肽的BcXYG3则无法诱导叶片坏死,推测该蛋白可能是被分泌到植物质外体空间发挥作用。BcXYG3基因在灰葡萄孢侵染阶段上调表达,但将其敲除或过量表达后,病菌的致病力、生长速度、产孢量和抗逆性无明显变化。此外,在本氏烟草叶片中注射纯化的BcXYG3能诱导植物对灰葡萄孢的抗性。综上所述,灰葡萄孢分泌蛋白BcXYG3可引起植物细胞坏死并参与诱导植物产生抗病性,在灰葡萄孢与植物互作中起着重要作用。研究结果为进一步阐明灰葡萄孢-寄主植物互作机理,以及为灰霉病害的有效防治提供理论依据和基因资源。

桃褐腐病是桃树主要病害之一,其大规模流行给果农带来巨大损失。目前,关于褐腐病的研究主要集中在病原菌的分离鉴定、抗药性、防治等方面,而对褐腐病菌致病机制的研究相对较少。本研究基于前期获得的桃褐腐病菌(Monilinia fructicola)侵染果实的早期转录组数据及基因组数据,通过PHI注释分析发现自噬相关基因MfATG1在M. fructicola侵染过程中可能发挥重要作用。通过基因敲除技术,获得MfATG1基因的敲低阳性转化子,并比较其与野生型菌株生长发育、致病力和其他抗逆性的差异,以解析其生物学功能。研究结果表明:MfATG1基因敲低影响M. fructicola菌丝形态和自噬过程,降低菌丝生长速率和致病力,但不影响孢子萌发。在NaCl胁迫条件下,MfATG1敲低提高了M. fructicola对NaCl的敏感性,表明MfATG1基因参与M. fructicola对盐胁迫的应答。在H₂O₂、SDS和刚果红胁迫条件下,敲低MfATG1降低了M. fructicola对其敏感性,表明MfATG1基因参与调控M. fructicola的细胞壁完整性以及氧化应激反应。

核转录因子Y (nuclear transcription factor Y, NF-Y) 在植物生长发育和非生物胁迫应答中起着重要的作用, 但对其参与昆虫、微生物互作的机制研究较少。本研究旨在鉴定高粱NF-Y家族的基因成员,分析其序列特征,测定在高粱组织基因表达时空差异及响应高粱蚜(Melanaphis sacchari)侵染和丝轴黑粉菌(Sporisorium reilianum)侵染,并分析了自然等位DNA变异和蛋白互作网络。在高粱基因组筛选到9个NF-YA、15个NF-YB和12个NF-YC亚家族成员,在10条染色体上不均匀分布,同一亚家族中的成员基因结构相似,且大多数亲缘关系较近的SbNF-Ys的外显子-内含子结构较为相似。蛋白结构域分析结果显示,CBFB_NFYA为NF-YA亚家族的保守结构域,CBFD_NFYB_HMF为NF-YB和NF-YC亚家族的保守结构域;对基因启动子顺式作用元件分析发现,SbNF-Ys的启动子区域含有大量核心元件,如光响应元件和多种响应环境和激素的元件;系统进化树分析表明,SbNF-Ys在进化过程上较为保守,单子叶和双子叶植物间不存在明显分化,高粱与玉米的NF-Ys关系最近;基因表达分析表明,高粱NF-Y家族成员在不同高粱品种和组织中的表达量存在显著差异。高粱蚜侵染后抗、感蚜品系SbNF-YB3.2g、SbNF-YB11.7g的表达水平显著升高;感丝黑穗病品系较抗病品系SbNF-YB10.2g和SbNF-YB11.7g的表达水平显著升高。检测到SNP/INDEL DNA变异可建立分子辅助育种标记。本研究初步分析了高粱NF-Y家族的基因结构与表达,旨在为高粱抗蚜虫、抗丝黑穗病育种提供理论基础。

由落叶松-杨栅锈菌(Melampsora larici-populina)侵染杨树叶片引起的杨树叶锈病是一种分布广泛且危害严重的杨树叶部病害。简单重复序列(Simple sequence repeats,SSRs)广泛分布于基因组中,不仅常作为遗传标记用于群体遗传学分析,也在基因和基因组的进化中发挥重要作用。本研究针对M. larici-populina在全基因组水平鉴定出10 628个SSR位点,发现单核苷酸重复占比最大,为53.2%,并且A/T重复是最丰富的碱基类型。SSR位点频率和分布类型在基因组不同区域中各具特色,如3'转录非翻译区(3'UTR)的SSR频率最高,平均2.16 kb分布一个SSR位点,在基因编码区中三核苷酸重复是主要的类型。富集分析显示,与信号传递和细胞周期相关基因中出现SSR的几率更高。结合M. larici-populina全基因组InDel信息,预测出3 126个具有潜在多态性的SSR位点,随机选取10个位点设计引物进行多态性验证,显示7个SSR标记具有较高多态信息含量及3个SSR标记具有一定多态信息含量。研究结果有助于从全基因组水平上了解M. larici-populina的SSR特征,同时为后续该锈菌群体遗传学研究提供新颖且高效的SSR标记。

条锈病和白粉病是世界范围内小麦上的重要病害,培育和种植抗病品种是防治病害最经济有效的方法。为明确我国小麦条锈病主要流行区陕西、甘肃、四川、青海等地小麦主栽和区试品种对条锈病和白粉病的抗性水平及抗性基因的分布,分别利用小麦条锈菌(Puccinia striiformis f. sp. tritici,Pst)和小麦白粉菌(Blumeria graminis f. sp. tritici, Bgt)流行小种对194份小麦品种(系)进行苗期及成株期抗病性鉴定,结果表明,苗期有81份(41.80%)小麦材料对Pst混合小种表现抗性,33份(17.00%)对Bgt混合小种表现抗性;成株期分别有137份(70.60%)及111份(57.20%)小麦材料对Pst和Bgt混合小种表现抗性。利用Genotyping by Targeted Sequencing (GBTS)液相芯片技术对194份小麦材料进行分子检测,结果显示,携带Yr17、Yr26、Yr29、Yr30、Yr75、Yr78、Yr80、Yr82、YrAK58、YrSP 和Pm21基因的材料分别有16、9、68、62、31、88、3、5、16、9和1份,携带QYrsn.nwafu-1BL、QYrsn.nwafu-2AS、QYrqin.nwafu-2AL、QYrhm.nwafu-2BC、QYrsn.nwafu-3DL、QYr.nwafu-4BL、QYrsn.nwafu-6BS等抗条锈QTL位点的材料分别有85、30、145、47、8、78和89份,未检测到Yr18、Pm2a、Pm5e和PmV抗性基因。本研究为小麦抗病育种及抗病基因的合理布局提供了理论依据。

辣椒炭疽病是辣椒生产中主要病害之一,严重影响辣椒的产量和品质。为了明确目前山西省辣椒炭疽病主要病原Colletotrichum scovillei对于生产上常用防治辣椒炭疽病杀菌剂的敏感性现状,以及对戊唑醇的抗药性风险,本研究采用菌丝生长速率法,测定了山西省不同辣椒产区的93个C. scovillei菌株对4种常用杀菌剂的敏感性。通过室内药剂驯化获得抗戊唑醇C. scovillei菌株,研究这些抗性菌株的适合度,并分析它们和其它3种供试杀菌剂之间是否存在交互抗性。结果表明,戊唑醇、苯醚甲环唑和咪鲜胺对C. scovillei的平均EC₅₀值分别为0.364 1±0.019 2、3.126 7±1.221 2和0.817 1±0.328 3 μg·mL^-1,供试C. scovillei菌株对这3种杀菌剂的敏感性频率分布均为连续的单峰曲线,呈近似正态分布,未出现敏感性降低的亚群;对吡唑醚菌酯的平均EC₅₀值为0.123 6±0.190 8 μg·mL^-1,最大值与最小值相差2 930.98倍,敏感性分布呈左偏态,已出现敏感性降低亚群。室内药剂驯化获得10株抗戊唑醇C. scovillei菌株(低抗6株,中抗4株),其中有6株对戊唑醇的抗性可稳定遗传;和对戊唑醇表现敏感的亲本菌株相比,抗性菌株菌丝生长速率、产孢量及致病力均降低。交互抗性研究结果表明,对于C. scovillei菌株,戊唑醇与苯醚甲环唑之间存在交互抗性,与咪鲜胺、吡唑醚菌酯之间无交互抗性。研究结果为山西省辣椒炭疽病的防治提供了参考。

为了明确中国柑橘褐斑病菌的种群组成及优势种对琥珀酸脱氢酶抑制剂 (SDHIs) 的敏感性,本研究针对7个柑橘主产区的135个柑橘褐斑病样品进行了病原分离鉴定和优势种群的药剂敏感性测试。在本次分离获得的155个链格孢属(Alternaria)菌株中,盖森链格孢 (A. gaisen) 的数量已超越交链格孢 (A. alternata),成为新的优势病原种群。采用菌丝生长速率法测定了100个盖森链格孢菌株对啶酰菌胺和氟吡菌酰胺的敏感性,结果表明:啶酰菌胺对供试菌株的EC₅₀值范围为0.4129~4.7137 mg·L^-1,平均值为1.9257 mg·L^-1;氟吡菌酰胺对供试菌株的EC₅₀值范围为0.1272~3.3648 mg·L^-1,平均值为1.1149 mg·L^-1。盖森链格孢群体对这两种药剂的敏感性分布均为连续的单峰曲线,且通过K-S检验 (Kolmogorov-Smirnov test) 验证符合正态分布,未发现抗药性菌株。因此,1.9257 mg·L^-1和1.1149 mg·L^-1可分别被确定为盖森链格孢对啶酰菌胺和氟吡菌酰胺的敏感性基线。此外,来自不同地区的盖森链格孢对这两种药剂的敏感性差异不显著 (P＞0.05),所有供试菌株对氟吡菌酰胺的敏感性普遍高于啶酰菌胺。本研究为利用啶酰菌胺和氟吡菌酰胺防治柑橘褐斑病提供了重要的数据支持和技术依据。

小麦茎基腐病(Fusarium crown rot)是由假禾谷镰孢(Fusarium pseudograminearum)为主引起的土传病害,其侵染小麦产生各种毒素并造成小麦白穗现象,对小麦产量与粮食安全造成严重威胁。为明确戊唑醇对F. pseudograminearum不同生长发育时期的抑菌作用与对防治小麦茎基腐病的效果,本文研究了戊唑醇对F. pseudograminearum的菌丝生长、孢子萌发、芽管伸长、产孢的影响,建立了F. pseudograminearum对戊唑醇的敏感性基线,并进行了戊唑醇防治小麦茎基腐病的田间防效试验。结果表明,戊唑醇对F. pseudograminearum菌丝生长的EC₅₀值为(0.056 0±0.032 1) μg·mL^-1,对F. pseudograminearum孢子萌发的EC₅₀值＞50 μg·mL^-1;通过比较3株供试F. pseudograminearum的菌丝生长、孢子萌发、芽管伸长与产孢对戊唑醇的敏感性,发现孢子萌发的EC₅₀值最高,EC₅₀值＞8 μg·mL^-1;芽管伸长与产孢的EC₅₀值最低,EC₅₀值＜0.01 μg·mL^-1;且不同质量浓度戊唑醇处理使F. pseudograminearum菌丝、芽管与分生孢子均造成不同程度的畸形,戊唑醇质量浓度越高致畸作用越明显;430 g·L^-1戊唑醇悬浮种衣剂(Flowable concentrate for seed treatment,FS)对小麦不同生长时期小麦茎基腐病的田间防效结果表明,拔节期时伊川试验田的相对防效为67.38%,新安试验田的相对防效为71.85%;灌浆后期时伊川试验田的相对防治效果为37.19%,新安试验田的相对防效为36.89%;乳熟期时伊川试验田的小麦白穗率均为6.30%,新安试验田的小麦白穗率为7.21%;430 g·L^-1戊唑醇FS防治效果与对照药剂25 g·L^-1咯菌腈FS之间无显著差异;两种杀菌剂处理后与对照相比千粒质量无显著变化,表明小麦经过戊唑醇FS拌种后不影响来年麦粒的质量。结果表明戊唑醇对F. pseudograminearum的菌丝生长、产孢和芽管伸长具有较强的抑制作用,戊唑醇拌种可有效防治小麦茎基腐病。研究结果为戊唑醇在小麦茎基腐病防治中的合理应用提供了参考。

为确定贝莱斯芽孢杆菌(Bacillus velezensis)C11菌株产生的挥发性有机化合物(volatile organic compounds,VOCs)对番茄灰葡萄孢(Botrytis cinerea)的生防效果,采用双皿对扣法测定VOCs对番茄灰葡萄孢菌丝生长、分生孢子形成、细胞膜通透性、菌丝显微形态的影响,对番茄灰霉病的防治效果,以及对番茄体内抗性相关的POD、CAT酶活的影响。结果表明,B. velezensis C11 VOCs能显著抑制番茄灰葡萄孢菌丝生长,抑制率达78.35%;可造成番茄灰葡萄孢产孢量下降、细胞膜受损、菌丝形态改变等;对番茄灰霉病的防效达76.9%。进一步通过SPME-GC-MS检测B. velezensis C11 VOCs成分,共鉴定出27种物质,其中8种(2-庚酮、2-壬酮、6甲基-2-庚酮、2-甲氧基酚、2-乙基-5甲基吡嗪、2-十一醇、2-十三烷酮、2-十一酮)相对含量较高(占总含量5.43%)。当浓度为0.5 nmol·mL^-1时,这8种物质对番茄灰葡萄孢均有较好的抑菌活性。本研究明确了B. velezensis C11菌株可通过产生具有抑菌活性的VOCs发挥生防作用,同时初步分析鉴定了其VOCs中主要的活性抑菌组分,为深入解析该菌株的生防机制以及将其应用于生产实践提供了理论依据。

裸粒大麦(Hordeum vulgare L. var. nudum)在青藏高原俗称青稞,是在该区域内唯一被广泛种植的禾谷类主粮作物。穗腐病是近年来在青藏高原流行的一种青稞新病害,由禾生指葡孢霉(Dactylobotrys graminicola)侵染引起。该病菌的传播介体为穗螨(Siteroptes spp.),二者是互利共生关系,目前尚无有效防治穗腐病的方法。研究穗螨共生细菌的多样性,确定优势菌的种类,有助于揭示保持穗螨-病原菌复合体稳定性的调控机制,从而为穗腐病绿色防控技术体系的建立提供新线索。本研究中,从穗腐病流行区表层土壤和青稞病穗中收集穗螨的成螨,采用2种方法,即培养活体穗螨或经表面彻底消毒的穗螨研磨组织,分离来自穗螨(体表+体内)或仅来自体内的共生细菌,再通过16S rDNA特异引物测序,对分离所获菌株进行鉴定。结果显示,来自土壤中的穗螨,(体表+体内)共生细菌为23个属,体内共生细菌为16个属,其中有9个属在体表和体内均有分布。土壤穗螨(体表+体内)共生细菌群体中,放线菌门的微杆菌属(Microbacterium)、红球菌属(Rhodococcus)和链霉菌属(Streptomyces)是优势菌属,其次是假单胞菌门的假单胞菌属(Pseudomonas)和寡养单胞菌(Stenotropho-monas);土壤穗螨体内共生菌群中,Microbacterium(52.1%)和Pseudomonas(22.1%)比例明显高于穗螨(体表+体内)中的比例33.7%和6.8%,而Streptomyces仅分布于土壤穗螨的体表。来自青稞病穗中的穗螨,(体表+体内)共生细菌有16个属,体内共生细菌为18个属,其中有14个属在穗螨体内、外均有分布;假单胞菌门的3个属Stenotrophomonas、Pseudomonas和产碱杆菌属(Alcaligenes)是病穗中穗螨的优势共生细菌,而且所占比例显著高于土壤穗螨,其次是放线菌Microbacterium和Rhodococcus,二者所占比例显著低于土壤穗螨。从穗腐病流行区域土壤穗螨上检测到的放线菌门菌株数量是假单胞菌门的2.3~2.8倍,但青稞病穗中穗螨共生的假单胞菌门菌株数量是放线菌门的1.9~2.4倍。因此,表层土壤和青稞病穗中穗螨的共生细菌群体组分存在较大差异,其中Microbacterium、Rhodococcus、Streptomyces、Pseudomonas和Stenotrophomonas是优势共生菌,它们可能在促进穗螨赖以存活的营养来源D. graminicola侵染青稞幼穗和大量繁殖中发挥关键性作用。

利用光合细菌分离培养基从云南省玉溪市猕猴桃根际土中分离光合细菌,并测试其对烟草花叶病毒 (tobacco mosaic virus,TMV) 的抑制效果;同时,对分离到的光合细菌进行次生代谢产物5-氨基乙酰丙酸(5-aminolevulinic acid,5-ALA)产量测定;随后,对分离到的光合细菌菌株及其次生代谢产物5-ALA开展抗TMV的抑制效果测试,并对其抗病毒机理进行初步分析。所分离到的光合细菌菌株YN-1经形态学鉴定、革兰氏染色、碳源、氮源等生理生化测试以及16S rDNA序列分析,鉴定其为沼泽红假单胞菌 (Rhodopseudomonas palustris);YN-1的5-ALA产量高达4.37 mg·L^-1。分别喷施YN-1发酵原液和次生代谢产物5-ALA后均能降低供试本氏烟上烟草花叶病的发病率,结果显示YN-1发酵原液较清水和5 %氨基寡糖素水剂300倍液分别降低69.88%和24.24%;40 mg·L^-1 5-ALA较清水、5%氨基寡糖素水剂300倍液分别降低74.70%、36.37%。通过对供试本氏烟相关抗病基因复制水平的检测,发现喷施了YN-1发酵原液和5-ALA后,供试本氏烟SA途径抗病基因较对照有显著的上调。结果表明,所分离到的沼泽红假单胞菌YN-1菌株发酵原液及其40 mg·L^-1的次生代谢产物5-ALA能有效降低TMV对烟草的侵染。

In order to clarify the occurrence of root rot disease in Yunnan apple producing areas, the types of pathogens and the existence of new pathogens, this study aims to investigate the presence of root rot pathogens in Yunnan apple orchards and identify any potential new pathogens. Disease samples were collected from apple producing areas in Yunnan. The pathogens were obtained by tissue isolation, and the pathogenicity was verified by Koch's rule. The identification of pathogen was preliminarily determined by combining morphology. Furthermore, molecular biology identification was carried out based on the method of internal transcribed spacer and large subunit multi-locus gene joint construction. Phytopythium was isolated from Jian chuan County, Dali City, and Ning lang County, Lijiang City. It was confirmed through pathogenicity determination so that it could cause apple root rot. Through morphology combined with molecular biology characters. It was identified as Phytopythium litorale and P. cucurbitacearum. This study represents the first report of apple root rot caused by the pathogens P. litorale and P. cucurbitacearum in China. The results provide a theoretical basis for the development of monitoring disease occurrence and comprehensive control technology.

Broomcorn millet (Panicum miliaceum L.), one of the world's oldest cultivated crops, has excellent water use efficiency and is mainly used for dryland farming. In 2021, a new foliar disease of broomcorn millet occurred in Longdong of Gansu Province, China. The diseased leaves showed variably-sized, nearly circular brown blotches with dark brown margins, and the adaxial surfaces of blotches had small black dots. Based on morphological characteristics and multi-locus phylogenetic analysis involving ITS, LSU and RPB2, and the pathogenicity test, the pathogen of broomcorn millet causing leaf spot was identified as Boeremia exigua. To our knowledge, this is the first report of B. exigua causing leaf spot on broomcorn millet in China.

Prunus tomentosa is a deciduous shrub native to China that has been widely cultivated for an extended period throughout Eastern Asia for its flowers and fruit. Between 2021 and 2023, fruit anthracnose was observed in the Beijing and Shandong provinces of China. Symptoms initially presented as yellow, caviar-like patches on the fruit surface, which gradually enlarged into sunken brown spots, ultimately leading to fruit rot. To identify the causal agent, fungal isolate MYT24 as a representative strain was obtained from symptomatic fruits and identified as Colletotrichum fioriniae based on morphological characteristics and molecular phylogenetic analysis. The C. fioriniae was re-isolated from the disease fruit and the morphology was consistent with the original, fulfilling Koch’s postulates, which was confirmed as the causal agent of this disease. To our knowledge, this is the first report of C. fioriniae causing fruit anthracnose in P. tomentosa in China.

Hydrangea macrophylla, as one of the three major garden plants worldwide, has high ornamental and economic value. In March 2023, severe leaf spots were observed on H. macrophylla in the greenhouse in Xiqing District, Tianjin. Tissue separation was carried on to gain a pure strain that caused brown leaf spot on H. macrophylla, and its pathogenicity was confirmed based on Koch's postulates. According to morphological features and phylogenetic analyses of rDNA-ITS, GAPDH, and Alt a1 gene, the pathogen was identified as Alternaria alternata. This is the first report of A. alternata causing leaf spot on H. macrophylla in China, which is going to pave the road for disease diagnosis and effective control strategies.

Cigar is an important economic crop in Yunnan province. Recently, the wilt disease occurred seriously on cigar in Lincang city, Yunnan province, China. To explore the main pathogenic fungi of cigar wilt, pure strains were obtained from the disease samples by using the tissue isolation method. Twenty-one representative isolates were subsequently obtained and exhibited identical morphological characteristics. All isolates produced large conidia with sickle shap, small conidia with kidney shape, chlamydospores with round or oval shape; A representative isolate (YX39-1) was selected for molecular identification and the rDNA-ITS (GenBank accession No. ON918599), EF-1α (OR808022), β-tubulin (OP053690) and RPB2 (OP369287) gene sequences were 99.25%, 99.86%, 98.42% and 98.17% similar to those of Fusarium solani isolates (MT896771, ON843639, ON366357 and XM_046273849, respectively). Thus, the fungus represented by isolate YX39-1 was identified as F. solani based on cultural and morphological features. Pathogenic test showed that all inoculated plants exhibited symptoms similar to those observed in the field and YX39-1 was a strong pathogenic strain. The morphological and molecular identification of the fungal reisolated from inoculated plants confirmed its identity as F. solani, fulfilling Koch’s postulates. This is the first report of cigar wilt disease caused by F. solani causing in Lincang, Yunnan Province, China, which provides important information on the pathogen for disease management.