Spot Of Pepper Research Articles

First report of Xanthomonas euvesicatoria pv. euvesicatoria causing bacterial leaf spot of pepper in Kosovo

First report of Xanthomonas euvesicatoria pv. euvesicatoria causing bacterial leaf spot of pepper in Kosovo

Insights into bs5 resistance mechanisms in pepper against Xanthomonas euvesicatoria through transcriptome profiling

BackgroundBacterial spot of pepper (BSP), caused by four different Xanthomonas species, primarily X. euvesicatoria (Xe), poses a significant challenge in pepper cultivation. Host resistance is considered the most important approach for BSP control, offering long-term protection and sustainability. While breeding for resistance to BSP for many years focused on dominant R genes, introgression of recessive resistance has been a more recent focus of breeding programs. The molecular interactions underlying recessive resistance remain poorly understood.ResultsIn this study, transcriptomic analyses were performed to elucidate defense responses triggered by Xe race P6 infection by two distinct pepper lines: the Xe-resistant line ECW50R containing bs5, a recessive resistance gene that confers resistance to all pepper Xe races, and the Xe-susceptible line ECW. The results revealed a total of 3357 upregulated and 4091 downregulated genes at 0, 1, 2, and 4 days post-inoculation (dpi), with the highest number of differentially expressed genes (DEGs) observed at 2 dpi. Pathway analysis highlighted DEGs in key pathways such as plant-pathogen interaction, MAPK signaling pathway, plant hormone signal transduction, and photosynthesis – antenna proteins, along with cysteine and methionine metabolism. Notably, upregulation of genes associated with PAMP-Triggered Immunity (PTI) was observed, including components like FLS2, Ca-dependent pathways, Rboh, and reactive oxygen species (ROS) generation. In support of these results, infiltration of ECW50R leaves with bacterial suspension of Xe led to observable hydrogen peroxide accumulation without a rapid increase in electrolyte leakage, suggestive of the absence of Effector-Triggered Immunity (ETI). Furthermore, the study confirmed that bs5 does not disrupt the effector delivery system, as evidenced by incompatible interactions between avirulence genes and their corresponding dominant resistant genes in the bs5 background.ConclusionOverall, these findings provide insights into the molecular mechanisms underlying bs5-mediated resistance in pepper against Xe and suggest a robust defense mechanism in ECW50R, primarily mediated through PTI. Given that bs5 provides early strong response for resistance, combining this resistance with other dominant resistance genes will enhance the durability of resistance to BSP.

Effect of ethylene production by four pathogenic fungi on the postharvest diseases of green pepper (Capsicum annuum L.)

Ethylene produced by plants generally induces ripening and promotes decay, whereas the effect of ethylene produced by pathogens on plant diseases remains unclear. In this study, four ethylene-producing fungi including Alternaria alternata (A. alternata, Aa), Fusarium verticilliodes (F. verticillioides, Fv), Fusarium fujikuroi 1 (F. fujikuroi 1, Ff-1) and Fusarium fujikuroi 2 (F. fujikuroi 2, Ff-2) were severally inoculated in potato dextrose broth (PDB) media and postharvest green peppers, the ethylene production rates, disease indexes and chlorophyll fluorescence parameters were determined. The results showed that Ff-2 and Fv in the PDB media had the highest and almost the same ethylene production rates. After inoculation with green peppers, Ff-2 treated group still exhibited the highest ethylene production rate, whereas Aa treated group had a weak promotion effect on ethylene production. Moreover, the ethylene production rate of green peppers with mechanical injury was twice that without mechanical injury, and the ethylene production rates of green peppers treated with Aa, Ff-1, Ff-2 and Fv were 1.2, 2.6, 3.8 and 2.8 folds than those of green peppers without treatment, respectively. These results indicated that pathogen infection stimulated the synthesis of ethylene in green peppers. Correlation analysis indicated that the degreening of Fusarium-infected green pepper was significantly positively correlated with the ethylene production rate of green pepper, whereas the disease spot of Aa-infected green pepper had a significant positive correlations with the ethylene production rate of green peppers. Chlorophyll fluorescence results showed that the green peppers already suffered from severe disease after being infected with fungi for 4 days, and Fusarium infection caused early and serious stress, while the harm caused by A. alternata was relatively mild at the early stage. Our results clearly showed that α-keto-γ-methylthiobutyric acid (KMBA)-mediated ethylene synthesis was the major ethylene synthesis pathway in the four postharvest pathogenic fungi. All the results obtained suggested that ethylene might be the main infection factor of Fusarium spp. in green peppers. For pathogenic fungi, stimulating green peppers to produce high level of ethylene played a key role in the degreening of green peppers.

Xanthomonas as a Model System for Studying Pathogen Emergence and Evolution.

In this review, we highlight studies in which whole-genome sequencing, comparative genomics, and population genomics have provided unprecedented insights into past and ongoing pathogen evolution. These include new understandings of the adaptive evolution of secretion systems and their effectors. We focus on Xanthomonas pathosystems that have seen intensive study and improved our understanding of pathogen emergence and evolution, particularly in the context of host specialization: citrus canker, bacterial blight of rice, and bacterial spot of tomato and pepper. Across pathosystems, pathogens appear to follow a pattern of bursts of evolution and diversification that impact host adaptation. There remains a need for studies on the mechanisms of host range evolution and genetic exchange among closely related but differentially host-specialized species and to start moving beyond the study of specific strain and host cultivar pairwise interactions to thinking about these pathosystems in a community context.

The pathogenic diversity and host range of Colletotrichum spp. causing pepper spot and anthracnose of lychee (Litchi chinensis) in Australia

AbstractLychee pepper spot, a field disease affecting lychee fruit skin, pedicels and petioles, is caused by Colletotrichum siamense, a fungal pathogen within the gloeosporioides species complex. Members of Colletotrichum from the gloeosporioides species complex and occasionally those from the acutatum species complex also cause postharvest anthracnose of lychee. Pepper spot was first described in Australia many years after anthracnose on lychee was first described, giving rise to the hypothesis that a novel species or strain within the gloeosporioides species complex causes pepper spot. In the present study, 19 isolates of Colletotrichum spp., collected from pepper spot and anthracnose symptoms on lychee fruit, representing 13 different genotypes across five species, were inoculated onto lychee fruit in the field or on detached fruit in the laboratory, to understand more about their pathogenic diversity. We found that symptoms were specific to genotype of the pathogen, as three genetically similar isolates of C. siamense consistently caused pepper spot and anthracnose, whilst other isolates caused anthracnose only. Cross‐inoculation studies on detached fruit of lychee, banana, avocado and mango also provided some evidence of host specialization in isolates of C. siamense infecting lychee in Australia. Our experiments provided further evidence that detached fruit assays cannot be used as a reliable proxy for field inoculation studies. This research confirms that C. siamense is a causal agent of both lychee pepper spot and lychee anthracnose in Australia, and Colletotrichum alienum and Colletotrichum queenslandicum are reported as causal agents of anthracnose of lychee for the first time.

Draft genomes announcement of Vietnamese Xanthomonas euvesicatoria strains causing bacterial spot on pepper.

Xanthomonas euvesicatoria the primary causal agent of bacterial spot of pepper (BSP), poses a significant global challenge, resulting in severe defoliation and yield losses for pepper growers. We present the whole genome sequences of eight X. euvesicatoria strains associated with BSP in Vietnam. These genomes contribute to representation of pepper production regions in the global sample of X. euvesicatoria genomes, enabling the development of precise global disease management strategies.

Disease Occurrence, Incidence and Severity in Vegetable Gardens of Green-the-Home Project Beneficiaries in Baybay City and Hilongos, Leyte, Philippines

This survey aimed to identify the major diseases affecting the Green-the-Home (GTH) vegetable gardens project beneficiaries in Barangays Guadalupe and Marcos in Baybay City, Leyte, and Barangay Liberty, Hilongos, Leyte, Philippines. The study documented the occurrence, incidence, and severity of various vegetable diseases, including the existing pest management practices of vegetable growers. Disease incidence and severity observed in vegetable gardens varied depending on the type of disease, crop, and site. The surveyed crops included okra, upo, ampalaya, tomato, string beans, sweet pepper, chili, eggplant, and cucumber, which are common in the sampling areas. The most common diseases found within the three project sites were okra leaf mold, Cercospora leaf spot of ampalaya, Cercospora leaf spot of sweet pepper, and Cercospora leaf spot of chili. The majority of vegetable growers employed physical and cultural pest management approaches, such as weeds removal (66.6%), the use of nets (63.3%), intercropping (60%), tillage (50%) and bagging (46.6%). Disease occurrence in the areas was influenced by environmental factors such as rainfall, temperature, humidity, and poor management practices of vegetable gardens. Since Baybay and Hilongos have the same climatic pattern, such environmental factors are consistent in both areas. It is recommended that the Government and other lead agencies, such as the Department of Agriculture (DA) and the Agricultural Training Institute (ATI), assist GTH in promoting pests and diseases literacy programs among vegetable growers. They should also provide adequate access to extension services and disseminate appropriate, safe, and long-term pest management strategies to vegetable growers.

Assessing the Impact of Futures Trading Availability on Spot Market Dynamics of Indian Pepper

Modern agricultural tools boost productivity across crops. Pepper, a lucrative cash crop, attracts global cultivation, bolstering yields. However, heightened productivity brings risks like price fluctuations and supply-demand imbalances, impacting the market's stability and success. Utilizing futures contracts is a common strategy to mitigate risks, yet the challenge lies in ensuring the availability of futures aligned with the specific commodity and contract size. In the Indian context, where pepper futures have been introduced and withdrawn multiple times, this study seeks to examine the impact of the presence or absence of pepper futures trading on pepper spot prices. Econometric techniques such as the Johansen cointegration test, VECM, Granger causality test, and ARIMA modeling were employed to analyze market integration and price autocorrelation. Findings indicate short-term cointegration between pepper spot and futures markets, striving for long-term equilibrium. Futures were found to influence the pepper spot market. ARIMA modeling recommended ARIMA(11,1,7) during futures presence and ARIMA(1,2,2) during absence for representing distinct periods.

Correction for article ‘Identification of Colletotrichum siamense causing litchi pepper spot disease in mainland China’

Correction for article ‘Identification of <i>Colletotrichum siamense</i> causing litchi pepper spot disease in mainland China’

Characterization of Pseudomonas capsici strains from pepper and tomato.

Disease outbreaks of bacterial leaf spot and blight of pepper and tomato often occur in both transplant- and field-production systems worldwide. In some cases, the outbreaks are caused by novel bacterial species. Characterization of these novel bacterial species are critical in developing diagnostic assays and identifying management options for pathogen monitoring and sustainable production, respectively. We characterized strains belonging to novel Pseudomonas species that are responsible for outbreaks in pepper and tomato both in transplant-houses and in production fields in Georgia, USA. Phylogenomic analyses and whole genome sequence indices demonstrated that the pepper and tomato strains belonged to P. capsici. The whole-genome comparison revealed that 13 Pseudomonas strains from diverse isolation sources that were curated in NCBI were indeed P. capsici indicating a potential wide-host range for this bacterial species. Our greenhouse-based host-range assay also indicated that P. capsici strains were pathogenic on pepper, tomato, eggplant, cabbage, lettuce, and watermelon corroborating a wide-host-range. A phylogenetic tree inferred from the whole genome sequence data showed that the P. capsici strains from Georgia (pepper and tomato) were genetically diverse, and were closely related to tomato P. capsici strains from Florida. Genomic presence of traditional bacterial virulence factors in P. capsici strains was also determined. Pseudomonascapsici strains encode one set of type I secretion system, two sets of type II secretion systems, one set of type III secretion system, two sets of type V secretion systems, three sets of type VI secretion systems, and various secondary metabolite gene clusters including lipopeptides. In in-vitro assays, it was demonstrated that six out of seven P. capsici strains (pepper and tomato strains from Georgia) were not sensitive to 0.8 mM CuSO4. When the genomes of copper-tolerant strains were compared with the copper-sensitive strains, it was observed that the former strains encode a cluster of genes related to copper tolerance, which were absent in the genomes of copper-sensitive strains. Considering the ability of P. capsici strains to infect a range of vegetable hosts and possession of a wide range of bacterial virulence factors, secondary metabolites, and copper-tolerance genes, we envision that the management of this pathogen might potentially be a challenge.

Whole-Genome-Sequence-Based Classification of Xanthomonas euvesicatoria pv. eucalypti and Computational Analysis of the Type III Secretion System.

Xanthomonas spp. infect a wide range of annual and perennial plants. Bacterial blight in young seedlings of Eucalyptus spp. in Indonesia was originally identified as X. perforans. However, these strains failed to elicit a hypersensitive response (HR) on either tomatoes or peppers. Two of the strains, EPK43 and BCC 972, when infiltrated into tomato and pepper leaves, failed to grow to significant levels in comparison with well-characterized X. euvesicatoria pv. perforans (Xp) strains. Furthermore, spray inoculation of 'Bonny Best' tomato plants with a bacterial suspension of the Eucalyptus strains resulted in no obvious symptoms. We sequenced the whole genomes of eight strains isolated from two Eucalyptus species between 2007 and 2015. The strains had average nucleotide identities (ANIs) of at least 97.8 with Xp and X. euvesicatoria pv. euvesicatoria (Xeu) strains, both of which are causal agents of bacterial spot of tomatoes and peppers. A comparison of the Eucalyptus strains revealed that the ANI values were >99.99% with each other. Core genome phylogeny clustered all Eucalyptus strains with X. euvesicatoria pv. rosa. They formed separate clades, which included X. euvesicatoria pv. alangii, X. euvesicatoria pv. citrumelonis, and X. euvesicatoria pv. alfalfae. Based on ANI, phylogenetic relationships, and pathogenicity, we designated these Eucalyptus strains as X. euvesicatoria pv. eucalypti (Xee). Comparative analysis of sequenced strains provided unique profiles of type III secretion effectors. Core effector XopD, present in all pathogenic Xp and Xeu strains, was absent in the Xee strains. Comparison of the hrp clusters of Xee, Xp, and Xeu genomes revealed that HrpE in Xee strains was very different from that in Xp and Xeu. To determine if it was functional, we deleted the gene and complemented with the Xee hrpE, confirming it was essential for secretion of type III effectors. HrpE has a hypervariable N-terminus in Xanthomonas spp., in which the N-terminus of Xee strains differs significantly from those of Xeu and Xp strains.

Developing Fermentation Liquid of Bacillus amyloliquefaciens PMB04 to Control Bacterial Leaf Spot of Sweet Pepper

Sweet pepper is an important vegetable in the world. Bacterial leaf spot, caused by the pathogen Xanthomonas perforans, is a limiting factor that significantly reduces the quality and yield of sweet peppers. The use of chemical fungicides is currently the main disease-control method for bacterial leaf spot disease. It is important to develop an eco-friendly biocontrol method by using antagonistic microorganisms. Bacillus amyloliquefaciens PMB04 has strong antagonistic effects against pathogens and can inhibit the occurrence of diseases. B. amyloliquefaciens PMB04 has the potential for the development of a disease-control product. Primarily, PMB04 contained a strong inhibitory effect against all isolated X. perforans strains. In the inoculation assay, the severity of bacterial leaf spot disease on sweet peppers was reduced by PMB04 bacterial suspensions. To increase the convenience of field applications in future prospects, the development of the PMB04 fermentation liquid was carried out using different ratios of brown sugar and yeast extract in a 30 L fermentation tank. The results exhibited that the fermentation liquid of the 3-1 and 2-1 formulas obtained the highest bacterial population in a 30 L fermentation tank. The fermentation liquid of the 0.5-0.5 formula was the most stable formula for two different conditions in terms of a consistent bacterial population and sporulation. In addition, the 200-fold dilution of the 3-1 and 0.5-0.5 fermentation liquids revealed the best control efficacy on bacterial leaf spot disease of sweet peppers. Additionally, the results of the 0.5-0.5 fermentation liquid (PMB4FL) with different dilution concentrations also demonstrated that the 200- and 500-fold dilutions had the best control efficacy. To understand the effect of commonly used copper-containing fungicides on sweet peppers on the application of microbial agent PMB4FL, the effects of copper hydroxide and tribasic copper sulfate on the growth of X. perforans strains and B. amyloliquefaciens PMB04 were assayed. The results exhibited that the above two fungicides did not have any inhibitory effect on the growth of PMB04 but had a strong inhibitory effect on the X. perforans strain. In the follow-up control experiment, the treatment of copper hydroxide had no synergistic effect with PMB4FL to control bacterial leaf spot disease. We concluded that the use of the PMB4FL fermentation liquid alone on the leaves could effectively control the occurrence of bacterial leaf spots in sweet pepper crops.

Identification of species and physiological races of Xanthomonas isolated from tomato (Solanum lycopersicum) and chili pepper (Capsicum annuum) in Sinaloa, Mexico

Bacterial spot of tomato and chili pepper, caused by four species of Xanthomonas and various races, is one of the diseases with the greatest impact on horticulture worldwide. The aim of this study was to identify the species and physiological races of Xanthomonas present in tomato (Solanum lycopersicum) and chili pepper (Capsicum annuum) crops in Sinaloa, Mexico. For this purpose, samples with typical symptoms of bacterial spot were collected in commercial fields of the different municipalities in the state of Sinaloa. Ninety-three bacteria were isolated on semi-selective medium as nutrient agar and yeast extract-dextrose. A total of 47 bacteria were identified as Xanthomonas by a combination of morphological, pathogenic, biochemical, physiological, and molecular tests. In addition, to characterize the morphological race of each strain, differential tomato (four) and chili pepper (six) lines were used. Molecular diagnostic using specific primers indicated that 83% corresponded to X. euvesicatoria, 10.6% to X. perforans, and 6.4% to X. vesicatoria. At the physiological race level, races T1, T2, T3, and T5 were detected in tomato; while the Xanthomonas races detected in chili pepper were P0, P3, P6, P8 and P10. This information updates previous data on the distribution of races of Xanthomonas that infect chili peppers in Sinaloa, since races P6 and P10 are reported for the first time.

Utilization of a New Hundred-Genomes Pipeline to Design a Rapid Duplex LAMP Detection Assay for Xanthomas euvesicatoria and X. vesicatoria in Tomato.

Xanthomonas euvesicatoria (Xe) and X. vesicatoria (Xv) are two economically important causal agents of bacterial spot (BS) of tomato and pepper. Management of BS in the field requires rapid and accurate detection. This work therefore aimed to develop a pipeline to design a simple, fast, and reliable assay for the detection of Xe and Xv by Loop-Mediated Isothermal Amplification (LAMP). A total of 109 publicly available whole genomic sequences of 24 different species of bacterial pathogens were used to design primers that would amplify the DNA of the two target species. Laboratory testing of the assay was performed on pure bacterial cultures and artificially infected plants, and amplification was conducted with both a sophisticated laboratory instrument and a simple mobile platform. The testing of the assay confirmed its specificity with a sensitivity reaching 1 pg μL-1 for both pathogens with an assay duration of 40 minutes on a mobile detection platform. Our diagnostics development pipeline enables the easy and fast design of a reliable detection assay in the genomics age. By validating the pipeline with Xe and Xv pathogens, we have simultaneously developed an assay with high specificity, sensitivity, and speed, which will allow it to be deployed, contributing to successful management of BS.

Mapping of the bs5 and bs6 non-race-specific recessive resistances against bacterial spot of pepper.

Bacterial spot caused by Xanthomonas euvesicatoria is a major disease of pepper (Capsicum annuum L.) in warm and humid production environments. Use of genetically resistant cultivars is an effective approach to manage bacterial spot. Two recessive resistance genes, bs5 and bs6, confer non-race-specific resistance against bacterial spot. The objective of our study was to map these two loci in the pepper genome. We used a genotyping-by-sequencing approach to initially map the position of the two resistances. Segregating populations for bs5 and bs6 were developed by crossing susceptible Early CalWonder (ECW) with near-isogenic lines ECW50R (bs5 introgression) or ECW60R (bs6 introgression). Following fine-mapping, bs5 was delimited to a ~535 Kbp interval on chromosome 3, and bs6 to a ~666 Kbp interval in chromosome 6. We identified 14 and 8 candidate resistance genes for bs5 and bs6, respectively, based on predicted protein coding polymorphisms between ECW and the corresponding resistant parent. This research enhances marker-assisted selection of bs5 and bs6 in breeding programs and is a crucial step towards elucidating the molecular mechanisms underlying the resistances.

Identification and Mapping of bs8, a Novel Locus Conferring Resistance to Bacterial Spot Caused by Xanthomonas gardneri.

Although cultivars possessing recessive resistance alleles provide effective control of bacterial spot of pepper (Capsicum annuum), the deployed resistance gene, bs5, is ineffective against Xanthomonas gardneri, one of the pathogenic species. Resistance against X. gardneri was identified in C. annuum accession PI 163192, and this study sought to characterize this novel resistance and to map the resistance gene(s) to the pepper genome. We crossed PI 163192 with the susceptible cultivar Early Calwonder (ECW) to develop resistant near-isogenic lines (NILs) of ECW, designated ECW80R. The novel resistance in ECW80R was determined to be quantitative, recessively inherited, and non-hypersensitive-response causing, and inhibits lesion expansion and chlorosis. Presence of the resistance in NILs decreased the in planta bacterial population by ninefold compared with ECW. Bulked segregant analysis of resistant and susceptible individuals from an F2 population using whole genome single nucleotide polymorphisms identified a major resistance locus within an approximate 6-Mbp interval on the subtelomeric region of chromosome 11. We developed markers spanning this region and used these to genotype backcross F2 populations, which further delimited the resistance locus within a 2.3-Mbp interval. The novel resistance locus has been designated bs8. ECW80R and the linked markers developed in this study should prove useful for breeders seeking to advance this resistance into commercially relevant germplasm and for pyramiding bs8 with other resistance alleles such as bs5 and bs6. The allele bs8 will help prolong the durability of bacterial spot resistance in pepper and improve resistance to multiple species of Xanthomonas.

First report of Stemphylium lycopersici causing gray leaf spot of pepper in Taiwan

First report of Stemphylium lycopersici causing gray leaf spot of pepper in Taiwan

Incorporation of engineered nanoparticles of biochar and fly ash against bacterial leaf spot of pepper

In agriculture, the search for higher net profit is the main challenge in the economy of the producers and nano biochar attracts increasing interest in recent years due to its unique environmental behavior and increasing the productivity of plants by inducing resistance against phytopathogens. The effect of rice straw biochar and fly ash nanoparticles (RSBNPs and FNPs, respectively) in combination with compost soil on bacterial leaf spot of pepper caused by Xanthomonascampestris pv. vesicatoria was investigated both in vitro and in vivo. The application of nanoparticles as soil amendment significantly improved the chili pepper plant growth. However, RSBNPs were more effective in enhancing the above and belowground plant biomass production. Moreover, both RSBNPs and FNPs, significantly reduced (30.5 and 22.5%, respectively), while RSBNPs had shown in vitro growth inhibition of X.campestris pv. vesicatoria by more than 50%. The X-ray diffractometry of RSBNPs and FNPs highlighted the unique composition of nano forms which possibly contributed in enhancing the plant defence against invading X.campestris pv. vesicatoria. Based on our findings, it is suggested that biochar and fly ash nanoparticles can be used for reclaiming the problem soil and enhance crop productivity depending upon the nature of the soil and the pathosystem under investigation.

Bacterial Spot of Tomato and Pepper in Africa: Diversity, Emergence of T5 Race, and Management.

Bacterial spot disease was first reported from South Africa by Ethel M. Doidge in 1920. In the ensuing century after the initial discovery, the pathogen has gained global attention in plant pathology research, providing insights into host–pathogen interactions, pathogen evolution, and effector discovery, such as the first discovery of transcription activation-like effectors, among many others. Four distinct genetic groups, including Xanthomonas euvesicatoria (proposed name: X. euvesicatoria pv. euvesicatoria), Xanthomonas perforans (proposed name: X. euvesicatoria pv. perforans), Xanthomonas gardneri (proposed name: Xanthomonas hortorum pv. gardneri), and Xanthomonas vesicatoria, are known to cause bacterial spot disease. Recently, a new race of a bacterial spot pathogen, race T5, which is a product of recombination between at least two Xanthomonas species, was reported in Nigeria. In this review, our focus is on the progress made on the African continent, vis-à-vis progress made in the global bacterial spot research community to provide a body of information useful for researchers in understanding the diversity, evolutionary changes, and management of the disease in Africa.

First Report of Xanthomonas euvesicatoria Causing Bacterial Leaf Spot of Pepper (Capsicum annuum) in Montenegro.

Leaf spot of pepper was observed on different pepper cultivars in central Montenegro during summer and early autumn in three consecutive growing seasons (2017 - 2019). Necrotic spots were numerous, varying in size, irregular in shape, brown, and surrounded by a weak halo. The most intensive symptoms were observed on lower leaves. In conditions conducive or the infection, the lesions merged resulting in the leaf drop. Symptoms were not observed on pepper stems and fruits. A total of seventeen bacterial strains were isolated from infected pepper leaves collected in seven different localities in the seasons of 2017-19. They formed yellow, convex, and mucoid colonies on yeast extract-dextrose-CaCO3 (YDC) medium and induced hypersensitive reaction in tobacco leaves. They were Gram negative, strictly aerobic, oxidase negative, catalase-positive, hydrolyzed gelatine and esculin and did not reduce nitrate, nor grew on 0.1% TTC and at 37°C. Out of tested 17 strains, eight hydrolyzed starch and three showed pectolytic activity, thus differing in these biochemical traits from Xanthomonas euvesicatoria (Xe) the reference strain KFB 1 (Obradović et al., 2004) used in all tests as a positive control. PCR analysis, with primer pair XeF/XeR, produced a single characteristic band of 173 bp in all 17 strains (Koenraadt et al. 2009). Additionally, the BOX-PCR profile of all the strains produced with the BOX A1R primer (Schaad et al. 2001) showed 100% homology with KFB 1. Based on the locality and year of isolation, nine strains were selected for amplification and partial sequencing of the gyrB gene using sets of primers described by Parkinson et al. (2007). Obtained partial DNA sequences showed that all nine strains (GenBank nos. MZ569011, MZ574079, MZ574080, MZ574081, MZ574082, MZ574083, MZ574084, MZ574085, and MZ574086) share 99.86 to 100% identity of gyrB sequence with Xe type strain ICPM:109 as well as 98.71 to 100 % of gyrB sequence identity with Xe strain LMG930 isolated from pepper in The United States. Pathogenicity of all strains was confirmed by spraying young pepper plants (cv. Slonovo uvo) using a handheld sprayer with the bacterial suspension (108 CFU/ml of sterile tap water), in three replicates. Sterile distilled water and reference Xe strain (KFB 1) were used as negative and positive controls, respectively. The inoculated plants were incubated under plastic bags in the greenhouse providing high humidity conditions for 48h. Symptoms were monitored for two weeks after inoculation. Lesions surrounded by a halo appeared on leaves of all inoculated plants within 10 to 15 days after inoculation, while plants inoculated with SDW remained symptomless. Koch's postulates were confirmed by reisolation of the pathogen from necrotic tissue and identity check by PCR using primer set of Koenraadt et al. (2009). The pathogen race was determined according to the reaction of cv. Early Calwonder (ECW) and its isogenic lines (ECW-10R, ECW-20R, ECW-30R) (Stall et al. 2009). Obtained results indicated that all tested strains and reference strain Xe (KFB 1) belong to the pepper race P8. Based on pathogenic, biochemical, and molecular characteristics, the strains isolated from pepper leaves in Montenegro were identified as X. euvesicatoria. Pepper production is particularly significant for small farmers in Montenegro. Favorable climate, use of noncertified seed and lack of crop rotation contributes to the disease occurrence and severity. The disease has probably been around for years but the etiology was not confirmed so far. This is the first report of X. euvesicatoria affecting pepper in this country.