Investigation of Main Fungal Diseases of Pepper (Piper nigrum L.) in Hainan Province and Their Pathogen Identification

[ Objective ] The paper was to confirm the current major diseases of pepper in Hainan Province and their corresponding pathogens. [ Method ] The pep- per gardens in 13 main cultivation regions of pepper in Hainan Province were systematically investigated, and the pathogens of the obtained specimens were isolated and identified. [ Result] Seven fungal diseases in pepper were totally investigated, including blast, anthracnose, blight, slow wilt, root rot, basal rot and scleretin- ia disease. Currently, the diseases with serious damage on pepper include blast, anthracnese, blight and slow wilt. [ Conclusion] The result provides the theoreti- cal basis for the integrated control of diseases in pepper, and is also benefit for scientific research workers to master the latest dynamic of diseases.

Pathogen Identification and Phylogenetic Analysis of Sugarcane Rust in Plateau Areas at Low Latitudes

[Objectives]This study was conducted to clarify the species,occurrence and distribution characteristics of sugarcane rust pathogens in low-latitude plateau sugarcane rust areas of Yunnan Province and the phylogenetic relationship between the pathogens and that between them and other rust fungi of the genus Puccinia.[Methods]Fifty seven sugarcane rust samples collected from the sugarcane areas of Baoshan,Lincang,Menghai,Menglian,Ximeng,Lancang and Wenshan in Yunnan were subjected to molecular identification.[Results]The four sugarcane rust samples from Haiyin1 hao in Menghai,Yunnan Province belonged to orange rust of sugarcane,and the pathogen was Puccinia kuehnii Butler.;and other 53 samples of sugarcane rust belonged to brown rust of sugarcane,and the pathogen was Puccinia melanocephala Syd.et P.Syd.The rDNA sequences of other rust fungi from the genus Puccinia were downloaded from GenBank and used for the construction of an NJ tree for systematic evolution analysis together with the sequences obtained in this study.The results showed that the four P.kuehnii sequences obtained in this study were clustered with Puccinia polysora(GenBank accession number:GU058024)into one group,and they were close genetically;the 53 P.melanocephala sequences were clustered with P.nakanishikii(GenBank accession number:GU058002),P.rufipes(GenBank accession number:AJ296545),Aecidium deutziae(GenBank accession number:KU309317)and P.coronata(GenBank accession number:DQ354526)into one group,and they had a close genetic relationship;and the genetic relationship of the two species of sugarcane rust fungi identified in this study was relatively distant.[Conclusions]This study provides a scientific basis for sugarcane rust epidemic prediction,disease resistance breeding,and precise prevention and control.

Preliminary Identification of Loquat Leaf Mould Pathogenic Fungus in Mengzi City of Yunnan Province

[Objective] The study aimed to investigate the Ioquat leaf mould disease in Mengzi City of Yunnan Province and lay the foundation for determination of effective prevention and control methods.[Method] Loquat leaf mould pathogenic fungus was isolated by tissue separation method and inoculated with conidial suspension.The pathogenicity of Ioquat leaf mould pathogen was verified by Koch＇s postulate.Under a microscope,mycelial morphology and conidial fructification were observed,spore sizes were measured,and Ioquat leaf mould pathogen was identified according to the morphological characteristics.[Result] Velvet-like,olive green fungal colonies were generated on PDA medium.Conidiophores erect,apex curved,dark brown,smooth,with obvious spore marks and no diaphragm,（33.0-152.8） μm×（2.6-4.0）μm.Cladosporium was brown or pale olive with spore marks,monocelled or with one diaphragm,（7.1-19.0） μm × （1.9-5.9） μm.Conidia concatenate （2-4）,oval or spherical,with no spore mark,light olive,monocelled,smooth,（2.1-9.4） μm × （1.2-2.6） μm.[Conclusion] Loquat leaf mold disease began to occur in the germination period of spring shoots and summer shoots and became serious in the germination period of autumn shoots.Sooty mold-like layer grew on both front and back surfaces and densely covered the whole leaves,thus seriously affecting the photosynthesis of plants.The pathogen was preliminarily identified as Cladosporium eriobotryae Pass.＆ Beltrani.

Isolation and Preliminary Identification of the Pathogen of Anthracnose in Camellia sp.

The pathogens of anthraenose sampled from leaves and fruits of Camellia oleifera in Cenxi City and C. vietnamensis in Ningming country, Guangxi Prov- ince, were isolated via tissue methods and four isolates were obtained. Morphological description and phylogenetic analysis were made based on rDNA ITS se- quences. The results showed that the strains 742, GW2 and CR1 isolated from leaves were clustered into one group, and the strain CRF1 isolated from fruits was clustered into another group. All the four strains belonged to Colletotrichum gloeosporioides complex.

Pathogenic Identification of Leaf Tip Blight of Red-fleshed Kiwifruit in Qiandongnan Prefecture

[Objective]The paper was to investigate and identify new diseases in kiwifruit producing areas in Qiandongnan Prefecture to reduce the harm of diseases and ensure the quality of red-fleshed kiwifruit products.[Method]The pathogenic fungus was isolated from diseased leaves of redfleshed kiwifruit by tissue separation method,and DNA was sequenced by ribosomal rDNA-ITS(internal transcribed spacer)sequencing.Molecular evolutionary trees were built using MEGA4.0 software,and the pathogenic fungus was classified and identified combined with morphological obser-vation.[Result]Leaf tip blight was a new disease caused by Epicoccum sorghinum.It caused serious damage on red-fleshed kiwifruit.[Conclusion]The study supplements diseases of red-fleshed kiwifruit,and provides support for disease prevention and control in late stage.

Identification of Pathogens on Dry Blight Disease in Leaf Tip of Red-fleshed Kiwifruit in Qiandongnan Prefecture

In order to reduce the harm of diseases in red-fleshed kiwifruit in Qiandongnan Prefecture and ensure product quality, a new disease in the producing areas were investigated, and pathogen identification were carried out. The pathogen was isolated from diseased leaves by a tissue separation method. DNA sequencing was performed by the sequence analysis of ribosomal rDNA-ITS(Internal transcribed spacer) region, and a molecular evolutionary tree was constructed by the MEGA 4.0 software. The pathogenic fungus was classified and identified by combining morphological observation finally. The results showed that the dry blight disease in leaf tip was a new disease, which was caused by Epicoccum sorghinum, and it had a serious damage to red-fleshed kiwifruit.

Molecular Characterization,Morphology and Pathogenicity of Curvularia pseudobrachyspora,A New Causal Agent of Leaf Spot on Banana

[Objectives]The paper was to study molecular characterization,morphology and pathogenicity of Curvularia pseudobrachyspora,a new causal agent of leaf spot on banana.[Methods]Banana(Musa acuminate)leaves with streaks or long ellipse-shaped lesions were sampled in an orchard of Danzhou City,Hainan Province,China in 2021.Fungus isolates were isolated from the diseased tissues and further identified as C.pseudobrachyspora based on morphological characteristics of colony,conidiophore and spore,phylogenetic analyses of the ITS region,GAPDH and TEF-1αgenes.[Results]In the pathogenicity test,the fungus re-isolated from inoculated leaves with necrotic lesions was identified morphologically and molecularly,fulfilling Koch's postulates.[Conclusions]C.pseudobrachyspora is a new pathogen causing leaf spot of banana in China and the world.

Pathogenicity Assay and Molecular Identification of Fungi and Bacteria Associated with Diseases of Tomato in Malaysia

This study was conducted in order to determine the fungi and bacteria associated with tomato plants at Cameron Highlands Malaysia. The fungi which have been isolated and detected from tomato plants were: Fusarium oxysporum, F. solani, F. acuminatum, Rhizoctonia solani, Colletotrichum boninense, C. acutatum and Phoma destructiva. The bacteria which have been isolated and detected from tomato plants were: Ralstonia solanacearum, Xanthomonas vesicatoria, X. gardneri and Pseudomonas syringae. While the most pathogenic fungi were C. boninense, P. destructive and F. oxysporum with the disease incidence (89.6%, 86.6%, 85.6%) respectively, the most pathogenic bacteria were X. vesicatoria and R. solanacearum with the disease incidence (96.6% and 87.6%) respectively.

Identification of the Pathogen of Wufeng Maryland Tobacco Hollow Stalk

The morphological characteristics, pathogenicity and biological characteristics of the pathogen isolated from Maryland tobacco in Wufeng County of Hubei Province were studied in the laboratory. After cultivation on LB medium at 28℃ for48 h, the colonies were light yellow, circular or amorphous, translucent, with smooth and slightly concaved surface and neat edge. Observation under electron microscope showed that the isolates was red-shaped, decapsulated and gram-nega- tive in the size of （0.5 - 1.0） μm × （2.2 -3.0） μm, with 2 -8 flagella. After cultivation on CVP medium at 28 ℃ for 48 h, the colonies were sunken like a cup. The pathogen was able to grow in 5% NaCl medium at 37 ℃, and produced acid through glucose fermentation; it was facuhative anaerobic, and could use citrates, but could not produce indole. It was preliminarily confirmed that the pathogen causing Wufeng Maryland tobacco hollow stalk was Pectobacterium carotovorum subsp. carotovorum.

Isolation and Identification of Pathogenic Fungi Causing Decayin Luotian Chestnut during Late Storage Period and Research on Pathogenicity

In order to explore moldy mechanism of chestnut from Luotian County in storage process,the strains of pathogenic fungi were isolated from chestnuts after storage at room temperature for 70d.Six genera of fungi were found in chestnut through experimental identification,which were Ozoniumsp.,Fusarium sp.,Aspergillus sp.,Penicilliumsp.,Rhiopus sp.and Stachybotrys sp.,respectively.The re-inoculation tests had been conducted on pathogenic fungi whose isolating rate was greater than 10%.The result showed that the rest genera of fungi generally had no pathogenicity except Penicilliumsp.could infect non-injured chestnut with a lower moldy rate and lighter symptoms;but the moldy rate of strains was above 60% in injured inoculation and they showed heavy symptoms,among which the moldy rate of Ozoniumsp.and Aspergillus sp.were higher than 80%.The experimental results showed that injured chestnut were more likely to decay.Ozoniumsp.and Aspergillus sp.were important pathogenic fungi causing decay during storage process of chestnut.

Isolation and Identification of Pathogenic Bacteria Causing Bovine Subclinical Mastitis in Eastern Hebei Province

In this study, the milk samples of 1 021 cows in eight dairy farms in Eastern Hebei Province were collected and detected with LMT reagent and somatic cell count for subclinical mastitis. Pathogenic bacteria in subclinical mastitis positive milk samples were isolated and identified.The results showed that 60.63%（619/1 021） of the sampled cows were diagnosed with subclinical mastitis, and mixed infections accounted for 88.21%（546/619） of the cases. In addition, 82 strains of 14 species were isolated from the subclinical mastitis positive milk samples, including 36 strains of Staphylococcus（43.90%）, 33 strains of Streptococcus（40.24%）, 8 strains of Enterobacteriaceae（9.76%） and 5 strains of Corynebacterium（6.10%）, respectively. The results proved that Staphylococcus aureus and Streptococcus agalactiae are the main pathogenic bacteria causing bovine subclinical mastitis in Eastern Hebei Province.

Isolation and Identification of Root Rot Fungus of Astragalus membranaceus

The perennial root of Astragalus membranaceus is used as a medicine, while root rot is a main factor causing reduction of quality and commodity value of A. membranaceus . The screening and research of the pathogenic species and their characteristics could provide theoretical and practical basis for the control of this disease. A pathogenic strain was isolated and purified from the root part of four-year-old A. membranaceus , and identified by morphological and molecular biological methods as Fusarium oxysporum . This study will provide a theoretical basis for the research of the biological characteristics and control of F. oxysporum .

Identification of a new Hazelnut disease in Liaoning Province:Hazelnut husk brown rot

Hazelnut husk brown rot has been identified as a new disease in Liaoning Province in recent years.The objective of this study as to identify the pathogen.[Method]In this study,a standard sample of hazelnut husk brown rot was collected from Songmudao Base in Dalian City,Liaoning Province.The pathogen was identified by the studies of the morphology,pathogenicity,and analyses of ITS and LSU sequences.The pathogen was isolated and purified,which was confirmed by Koch’s postulates.The symptoms after inoculation were the same as those collected directly from a diseased tree,which showed that it was the pathogenic fungus.The cultural characteristics and conidia and the morphology of the pathogenic fungi were similar to those of Botrytis cinerea’s.The ITS sequences and LSU sequences were compared to the associated strain sequences in GenBank,with 100%identity to Botrytis cinerea(GenBank accession number:MN589848.1)and Botrytis cinerea(GenBank accession number:KU140653.1),respectively.The infection status of the pathogen on the hazelnut husks was also observed.The studies suggested that the pathogen leading to the hazelnut husk brown rot as a new disease in Liaoning Province was Botrytis cinerea.

Morphological and Molecular Identification of Curvularia geniculata Associated with Leaf Spot Disease of Banana in China

[Objectives]The paper was to identify the causal agent of leaf spot of banana in Hainnan,China.[Methods]Fungus isolates were isolated from the diseased tissues,and morphological characteristics of colony and spore were observed.Furthermore,phylogenetic analyses and pathogenicity test were conducted to confirm the pathogen.[Results]The fungus isolates from the diseased tissues was identified as Curvularia geniculata.[Conclusions]C.geniculata is a new pathogen causing leaf spot of banana in Hainan,China.This finding will help to broaden the distribution and host range of C.geniculata,indicating that it poses potential damage to banana in China.

First Report of Botryosphaeria dothidea Causing Sweet Osmanthus Leaf Dieback in China

Sweet osmanthus is one of the ten traditional famous flowers in China.The occurrence of the diseases caused by fungi other than Botryosphaeria spp.has been reported mainly from China on sweet osmanthus.A leaf dieback of sweet osmanthus caused by Botryosphaeria sp.was found for the first time in 2007 in Nanning City,Guangxi,China.The objectives of the present study were to isolate and characterize the causal organism of sweet osmanthus leaf dieback.The fungus was isolated from the lesions of affected sweet osmanthus leaves and its pathogenicity to sweet osmanthus was confirmed using a detached-leaf-inoculation method.The identification of the pathogen was carried out mainly based on the morphological characters and molecular analysis of internal transcribed spacer （ITS） sequences.The morphological characters of the pathogenic isolate GHX6 were agreed with that of Botryosphaeria dothidea.The ITS sequence of the isolate was amplified with primers ITS1 and ITS4,and submitted to GenBank （accession no.GQ368251）.Molecular analysis based on ITS sequence comparison between the isolate GHX6 and the other related fungi derived from GenBank supported that the causal agent of the sweet osmanthus leaf dieback belonged to Botryosphaeria dothidea.This is the first report of Botryosphaeria dothidea causing leaf dieback on sweet osmanthus in China.

Nanopore techniques as a potent tool in the diagnosis and treatment of endophthalmitis:a literature review

Endophthalmitis is a serious ophthalmic disease characterized by changes in the eye's posterior segment,such as hypopyon and intraocular inflammation,vitritis being a hallmark.Infection-caused endophthalmitis can lead to irreversible vision loss,accompanied by eye pain or eye distention,and in the most severe cases the removal of the eyeball.Microorganisms such as bacteria,fungi,viruses,and parasites typically account for the disease and the entry pathways of the microbial can be divided into either endogenous or exogenous approaches,according to the origin of the etiological agents.Exogenous endophthalmitis can be derived from various occasions(such as postoperative complications or trauma)while endogenous endophthalmitis results from the bloodstream which carries pathogens to the eye.This review aims to summarize the application of new technology in pathogen identification of endophthalmitis so as to prevent the disease and better guide clinical diagnosis and treatment.

云南甘蔗褐条病病原菌鉴定

褐条病是甘蔗生长中后期叶部主要真菌病害之一。近年来因多雨高湿及感病品种大面积种植导致褐条病在我国第二大糖料基地云南暴发为害成灾,减产减糖严重[1],严重制约云南蔗糖产业的高质量发展。以病原菌研究为基础的种植和选育抗病品种是防治这种病害最经济有效的措施。有关云南蔗区褐条病病原菌研究甚少,有效防控依据缺乏。本研究从云南不同蔗区采集褐条病病样进行分离与鉴定,旨在明确病原菌种类,以期为甘蔗褐条病的流行预测及综合防治提供科学依据。

南天竹一种新的叶斑病病原菌的分离鉴定

南天竹(Nandina domestica)为小檗科南天竹属,常绿灌木,形态优雅,果实球形鲜红且经冬不落,是赏果观叶的园林绿化植物。南天竹具有重要的药用价值,有“镇咳止喘、兴奋神经、强壮身体”之效[1]。在生长过程中,南天竹叶片易受炭疽病(Colletotrichum)危害[2]。

山东省草莓根腐病病原菌Mucor irregularis的鉴定

草莓(Fragria ananassa Duch)是蔷薇科草莓属植物,因其丰富的营养价值和较高的经济效益而被广泛种植于世界各地[1]。随着草莓产业的迅速发展,特别是设施栽培特殊环境及草莓的连茬种植,导致草莓根腐病逐年加重,对我国草莓产量增长和品质提高造成了严重威胁[2-3]。

Rapid and label-free classification of pathogens based on light scattering,reduced power spectral features and support vector machine

The rapid identification of pathogens is crucial in controlling the food quality and safety.The proposed system for the rapid and label-free identification of pathogens is based on the principle of laser scattering from the bacterial microbes.The clinical prototype consists of three parts:the laser beam,photodetectors,and the data acquisition system.The bacterial testing sample was mixed with 10 mL distilled water and placed inside the machine chamber.When the bacterial microbes pass by the laser beam,the scattering of light occurs due to variation in size,shape,and morphology.Due to this reason,different types of pathogens show their unique light scattering patterns.The photo-detectors were arranged at the surroundings of the sample at different angles to collect the scattered light.The photodetectors convert the scattered light intensity into a voltage waveform.The waveform features were acquired by using the power spectral characteristics,and the dimensionality of extracted features was reduced by applying minimal-redundancy-maximal-relevance criterion(mRMR).A support vector machine(SVM)classifier was developed by training the selected power spectral features for the classification of three different bacterial microbes.The resulting average identification accuracies of E.faecalis,E.coli and S.aureus were 99%,87%,and 94%,respectively.The ove rall experimental results yield a higher accuracy of 93.6%,indicating that the proposed device has the potential for label-free identification of pathogens with simplicity,rapidity,and cost-effectiveness.