This study isolated and characterized a novel positive-sense single-stranded RNA (+ ssRNA) mycovirus from Setosphaeria turcica , the phytopathogenic fungus causing maize northern leaf blight in Yunnan Province, which was tentatively designated as Setosphaeria turcica fusarivirus 2 (StFV2). The complete genome of StFV2 is 6,609 nucleotides in length with a GC content of 45%, and RACE amplification results confirmed that the viral genome lacks a poly(A) tail. Its genome comprises two open reading frames. ORF1 encodes a replication-associated protein that contains an RNA-dependent RNA polymerase domain with the conserved GDD motif and an SF2-type helicase domain. ORF2 encodes a putative hydrophilic auxiliary protein. Sequence alignment analysis revealed that StFV2 shares the closest phylogenetic relationship with Setosphaeria turcica fusarivirus 1 (StFV1, accession no. MW489564) derived from S. turcica. The overall genomic nucleotide identity between the two viruses is 60.86%, while the amino acid sequence identities of ORF1 and ORF2 are 69.12% and 54.21%, respectively. Phylogenetic analysis verified that StFV2 belongs to the genus Alphafusarivirus within the family Fusariviridae . In accordance with the species demarcation criteria of the International Committee on Taxonomy of Viruses (ICTV) for the genus Alphafusarivirus , a strain with more than 20% sequence divergence in the full-length RdRp protein is defined as a novel species member. Thus, StFV2 should be classified as a novel member of the genus Alphafusarivirus . This study enriches the mycovirus resource repertoire associated with S. turcica, and provides a theoretical foundation for further exploring the interaction mechanisms between mycoviruses and fungal pathogens, as well as for excavating biocontrol agents against maize northern leaf blight.

In February 2022, leaf zonate spot disease afflicted Aloe vera L. in Yunnan, China, endangering the $39 billion industry with 0.33ha under cultivation (Wan 2015). The disease manifested with watery spots progressing into oval or circular necrosis lesions, characterized by a dark center surrounded by a gray-brown zone. In the late stage of the disease, lesions regress in size and several small dark picnidia dots appeared on the gray-brown zone. The disease incidence ranged from 10% to 15% in three commercial plantations. If left uncontrolled, the disease could diminish the commercial value of Aloe vera plants. Eighteen symptomatic leaf samples underwent morphological and genetic identification. The samples were carefully washed with distilled water and 1×1 cm2 sections of tissue were excised using a sterile scalpel. The sections underwent surface-disinfection with 3% NaOCl for 3 min and 75% ethanol for 30 s. After three sterile water rinses the sections were air-dried. Subsequently, they were transferred to potato dextrose agar (PDA) before being incubated at 25 ℃ in the dark. Of the 18 samples, eight produced the colonies with similar morphological characteristics, named LH7. Isolate LH7 had downy to woolly aerial mycelia, initially pinkish white on the surface, and gradually turned greenish-olivaceous from the middle, and eventually turned dark brown to black after seven days. The fungus formed arthric chains in the aerial mycelium on PDA but did not produce conidiomata. The conidia, which occurred in arthric chains were 5.50-9.9 × 4.08-7.51 μm (mean 7.09× 5.26 μm, n=50) in size, cylindrical, brown, and 0-1 septate. To ascertain LH7’s pathogenicity, three healthy one-year old aloe plants were surface-sanitized with a 1% aqueous chlorine solution, rinsed with sterile water, and dried. Three leaves from each plant were punctuated and inoculated using conidial suspension (100 μl of 1x 106 conidial mL-1), while three control plants were inoculated with sterile distilled water. The pathogenicity tests were repeated twice. The inoculated plants were kept at 25 ℃ with a 12-hour light/12-hour dark cycle. After seven days, symptoms observed in the field appeared in the plants, while no disease occurred in the control plants. After 21 days, conidiomata formed on the inoculated leaves, averaging 116.92 μm (n=20) in diameter. These conidiomata were globose to subglobose, and brown to sub-brown. The fungus was successfully re-isolated from symptomatic tissue and the resulting colonies were morphologically consistent with isolate LH7. Based on the characteristics, the fungus was identified as Neoscytalidium dimidiatum (Philips et al. 2013). The specimen was deposited in China Center for Type Culture Collection ( CCTCC AF 2024001). This identification was confirmed through sequencing of ITS gene region of rDNA using ITS1/ITS4 (Imran et al. 2022). The sequence was submitted into GenBank database (ON878059). BLAST analysis of the LH7’s ITS amplicon showed 100% similarity with that of JN093303.1. A phylogenetic tree constructed using the maximum likelihood method revealed that ON878059 was clustered with JN093303.1. Previous studies have documented that pathogens such as Colletotrichum gloeosporioides (Penz.), Fusarium spp. and Rhizopus oryzae can also cause diseases in A. vera in China (Zhou et al. 2008; Ding et al. 2015). Additinonally, Cladosporium sphaerospermum, Pseudopestalotiopsis theae, and Lasiodiplodia theobromae have been identified as causal agents of aloe leaf spot diseases in India, Bangladesh and Malaysia (Avasthi et al. 2016; Ahmmed et al. 2022; Khoo et al. 2022). To our knowledge, this is the first report of N. dimidiatum causing leaf necrosis of aloe in China. Vigilant surveillance and disease control measures are imperative to mitigate potential losses in this region.

云南省玉溪市是我国草地贪夜蛾周年繁殖区.在2019-2021年,利用田间调查、性诱、高空灯诱等手段,对玉溪市草地贪夜蛾发生动态进行了调查.结果表明,草地贪夜蛾主要为害玉米,零星为害甘蔗、小麦、皇竹草;草地贪夜蛾在玉溪市可周年发生,在夏、秋季出现成虫诱捕高峰,2020、2021年发生程度轻于2019年;草地贪夜蛾成虫以夜间活动为主,18:00至翌日4:00成虫诱集量占24h总诱集量的82.55％,在19:00-20:00和23:00至翌日2:00各具1个诱集量高峰.

云南是全国杧果种植的重要区域,种植面积达11.5万hm2.通过调查,云南省杧果主要病虫害为蓟马、橘小实蝇、炭疽病和细菌性角斑病等,在分析研究主要病虫害的发生规律基础上,针对现阶段杧果登记用药情况及农药使用存在的问题,提出了杧果主要病虫害的绿色防控措施.

The complete genome sequence of a putative novel closterovirus, tentatively named "Dregea volubilis closterovirus 1" (DvCV1, GenBank accession no. MZ779122), infecting Dregea volubilis in China was determined using high-throughput sequencing (HTS). The complete genome sequence of DvCV1 consists of 16,165 nucleotides (nt) and contains nine ORFs. The genome structure of DvCV1 is typical of members of the genus Closterovirus. Complete genome sequence analysis showed that DvCV1 shares 41.4–48.4% nucleotide sequence identity with other known closteroviruses. The putative RNA-dependent RNA polymerase (RdRp), heat shock protein 70-like protein (HSP70h), and coat protein (CP) of DvCV1 share 46.80-62.65%, 31.06–51.80%, and 28.34–37.37% amino acid sequence identity, respectively, with the RdRp, HSP70h and CP of other closteroviruses. Phylogenetic analysis based on HSP70h aa sequences placed DvCV1 alongside other members of the genus Closterovirus in the family Closteroviridae. These results suggest that DvCV1 is a new member of the genus Closterovirus. This is the first report of a closterovirus infecting D. volubilis.

Paris mitovirus 1 (ParMV1) is a positive-sense RNA virus isolated from diseased Paris polyphylla var. yunnanensis plants in Wenshan, Yunnan. The complete genome sequence of ParMV1 consists of 2,751 nucleotides with a genome structure typical of the mitoviruses. ParMV1 genome has a single open reading frame (ORF: 358-2,637 nt) that encodes RNA-dependent RNA polymerase (RdRp) with a molecular mass of 86.42 kDa. ParMV1 contains six conserved motifs (Ι-VΙ) that are unique to mitoviruses. In addition, the 5′and 3′ terminals of the genome have a stable secondary structure, and the reverse complementary sequence forms a panhandle structure. Comparative genome analysis revealed that ParMV1 shares 23.1–40.6% amino acid (aa) and 32.3–45.7% nucleotide (nt) sequence identities with the RdRp of other mitoviruses. The phylogenetic tree inferred from RdRp aa sequence showed that ParMV1 clusters with mitoviruses, and hence should be considered as a new member of the genus Mitovirus in the family Motiviridae . This is the first report of a novel mitovirus infecting Paris polyphylla var. yunnanensis .

为明确云南省引起滇重楼(Paris polyphylla var.yunnanensis)病毒病的病原,以昆明市发现的花叶、斑驳症状的滇重楼叶片为样品,进行透射电镜观察、高通量测序和反转录(RT-PCR)检测.结果表明,观察到大小约(700～1000)nm×13 nm的线状病毒粒子;基于高通量测序结果设计特异性引物进行RT-PCR扩增并克隆,得到1条全长为10066个核苷酸(nt)的病毒序列,将该病毒暂命名为Paris virus 1(ParV1);BLAST比对分析表明,ParV1与马铃薯Y病毒属(Potyvirus)中的浙贝母花叶病毒(Thunberg fritillary mosaic virus,TFMV)具有最高为65.1％、68.9％的核苷酸及氨基酸(aa)序列同源性;多序列比对分析显示,ParV1多聚蛋白与potyviruses具有49.6％～65.1％的nt序列同源性及47.1％～68.9％的aa序列同源性;基于多聚蛋白氨基酸序列构建的系统发育树表明,该病毒与TFMV亲缘关系较近且聚为一个单独的分支.综上所述,确定ParV1属于Potyvirus的一种新病毒.将含ParV1的病毒汁液以机械摩擦的方法接种到心叶烟、本氏烟上对ParV1进行致病性初步测定.接种后的心叶烟植株叶片表现出明显病毒病症状,经RT-PCR及分子克隆在接种的心叶烟中检测到ParV1的存在,表明心叶烟植株受到ParV1的侵染,而接种的本氏烟上暂未检测到该病毒的存在.

柑橘病虫害的蔓延危害是柑橘生产的重要制约因素.近些年,随着云南省玉溪市柑橘种植面积的不断增加,柑橘病虫害发生种类增多,危害加重,致使玉溪市柑橘存在果实品质差、产量低等问题.2014-2020年采取定点调查和普查相结合的方法,对玉溪市柑橘主要病虫害进行详细调查反复核实,共发现病虫害127种,包括病害30种、蛛形纲、昆虫纲、腹足纲3纲10目44科有害生物97种,其中危害较重的病害有溃疡病Xanthomonas axonopodis pv.citri、黄龙病Candidatus Liberibacter spp.、疫菌褐腐病Phytophthora itrophthora、炭疽病Colletotrichumn gloeosporioides等4种,占病害种数13.3％;危害较为严重的虫害有柑橘全爪螨Panonychus ciri(McGregor)、柑橘潜叶蛾 Phyllocnistis citrella stainton、柑橘小实蝇Dacus dorsaliis(Hcndal)、橘蚜Toxoptera citricidus(Kirkaldy)、斜纹夜蛾Prodenia litura(Fabricius)、蓟马Scirtothrips citri(Moulton)等6种,占虫害种数的6.2％;虫害重于病害,优势种群集中.

旨在揭示胁迫培养后的镰刀菌与常规培养的镰刀菌对土壤熏蒸剂的敏感性差异.通过室内简易干燥器检测3种熏蒸剂(30％氯化苦乳油、30％1,3-二氯丙烯油悬浮剂、50％氰氨化钙颗粒剂)对镰刀菌的抑菌效果,筛选出EC50最小的熏蒸剂.对在不同pH、极端温度、不同盐浓度胁迫下培养的镰刀菌用EC50最小的熏蒸剂熏蒸72 h后再接种到常规条件下(pH 7,盐浓度为0,温度28℃)培养120 h,用十字交叉法测量菌饼直径.结果表明:30％氯化苦乳油对镰刀菌的EC50值最小,为0.21 mg/L.镰刀菌经过不同胁迫处理后用30％氯化苦乳油熏蒸,接种常规培养后,其抑制率在pH 5、6、7、8、9分别为15.82％、10.42％、24.37％、19.52％、15.13％,抑制率在盐胁迫0、10、100、200、400、800 mmol/L下分别为27.04％、28.84％、15.60％、21.33％、14.38％、11.12％;温度40℃15、10、5天培养120 h,4℃15、10、5天培养120 h的抑制率分别为87.52％、21.65％、26.85％,24.17％、24.35％、29.14％.不同胁迫处理后的镰刀菌对同一浓度的熏蒸剂的敏感性表现出差异,胁迫处理后的镰刀菌对熏蒸剂的敏感性比对照低,抑菌率比对照的抑菌率低.

柑橘溃疡病是由柑橘黄单胞柑橘属亚种引起的致病力最强、蔓延最广泛的危害柑橘产业的重要细菌性病害,被列为国内外检疫对象.近年随着冰糖橙、茂谷柑、沃柑种植面积的不断扩大,云南玉溪市柑橘溃疡病的发生逐年增加.2014-2018年,我们对柑橘溃疡病发生进行监测,分析其发生规律和特点,开展防治技术研究,并有针对性的提出了综合防治对策.

通过对玉溪市低热河谷区桔小实蝇种群动态规律进行监测,研究结果表明,桔小实蝇在此区可常年发生,11月至翌年5月种群数量相对较低,5月以后种群数量开始增长,至7月达到高峰.同时,不同海拔不同作物桔小实蝇发生危害也不同,为桔小实蝇科学防控提供理论依据.

对不同诱捕器及诱芯诱捕柑橘小实蝇进行试验.结果表明,4种处理对桔小实蝇都有一定的诱捕效果,但以处理A:果实蝇专用诱捕器+实蝇性诱剂的诱捕效果最佳,差异性显著,其次是处理C:实蝇粘胶板;处理B:黄板+实蝇性诱剂;处理D:黄板诱捕效果最差.

In this paper,made bacterial strain Klebsiella variicola SH -1 which was selected before as materi-al,explored colonization trends of Klebsiella variicola SH -1 on Dendrobium alternaria by rifampicin labeling,and then potting and greenhouse trials were conducted to discuss its control efficiency for Dendrobium alternaria.The results showed that SH -1 could colonize in Dendrobium,and the colonization trended to increase firstly and then decrease.After inoculation,colonization quantity reached the highest at 11d,15d and 20d,in roots,stems and leaves respectively,and then followed by a downward trend.Kept the relatively stable colonization level in Den-drobium,with 4.3 ×104 CFU /g,2.32 ×104 CFU /g and 1.84 ×104 CFU /g in roots,stems and leaves after 35d, respectively.The result of potted tests on prevention of the Dendrobium alternaria showed that SH -1 had obvious control effect on Dendrobium alternaria,the control effect was the same as conventional medicine Dimetachlone that the relative control effect reached 72%,which could reach 71.53%.

<正>洼垤乡位于元江县东南部,乡政府驻地距县城74km,平均海拔1380m,年平均气温18℃,年平均降雨量600～980mm,总耕地面积1174.5hm2。2007年全乡种植烤烟1002.7hm2,收购烟叶总量1387079kg,该乡是我县主要种烟乡,同时,也是水利条件较差的乡,历年来在烤烟收后大部分土地是空闲着,种植小麦、油菜等作物因干旱产量低,农民