Potato Rot Research Articles

Effects of Rotten Vegetable-Based Low-Cost Media on the Growth and Morphology of an Astaxanthin-Producing Green Alga, Monoraphidium Littorale

Growing microalgae on vegetable waste (rotten potatoes) media is not only a plausible technique to replace expensive commercial media but also a way of reducing feed costs for rearing zooplankton and fish larvae in aquaculture. As a way of starting an inevitable step up, Monoraphidium littorale was grown in 25% (T1), 50% (T2), and 75% (T3) of digested rotten potato supernatant (DRPS) and at the same time in Bold Basal Medium (BBM) as a control (T4) for 16 days. The highest cell density of M. littorale was recorded in T1, followed by T4, T2, and T3. A similar increasing trend of chlorophyll-a and optical density was also observed during the experimental period. The study also ascertained T1 as a potential growth medium where M. littorale showed superior biomass production which was significantly higher ( P < 0.05 ) than other treatments. It was also worth mentioning that the highest ( P < 0.05 ) protein content was determined in T1 at the end of the cultivation time. Similarly, a highly significant difference ( P < 0.05 ) was also found in the lipid content of the microalgae grown in T1 and T4. Furthermore, the morphology of the cells of M. littorale was found to be strongly affected by the DRPS concentrations and BBM. Thus, the lower concentration of the DRPS served as the best medium for enhancing the growth and biomass of M. littorale. Consequently, to expedite the sustainable progression of microalgal production, cost-effective culture techniques by using different wastes may be adopted.

Pectobacterium punjabense causing soft rot and blackleg of potato in Sinaloa, Mexico

Pectobacterium punjabense causing soft rot and blackleg of potato in Sinaloa, Mexico

Development of plant pathogen detection and diagnostic techniques for downy mildew of onion, foot rot of sweet potato, and citrus greening

Development of plant pathogen detection and diagnostic techniques for downy mildew of onion, foot rot of sweet potato, and citrus greening

Characterisation of Pectinolytic Bacillus pumilus and Paenibacillus amyloliticus Strains, New Pathogens of Potato in Tunisia

Soft rot disease in potato is a major problem in fields and warehouses all over the world. Although it is known that bacteria from the genera Pectobacterium and Dickeya are the main causative agents of soft rot diseases, recent studies indicate the involvement of pectinolytic Bacillus and Paenibacillus in this disease. In the present research, samples of potato with soft rot symptoms were collected from eight governorates of Tunisia. Two hundred and seventy bacterial isolates were acquired from tubers. Twenty of the isolated strains indicted pectinolytic activity by forming deep cavities on crystal violet pectate medium. All pectinolytic isolates were able to macerate potato tuber tissue. Phenotypic characterisation showed that these isolates were Gram-positive bacilli, exhibiting pectinolytic, cellulolytic, proteolytic and amylolytic activity. The majority of the isolates indicated swimming and swarming motility. The application of API test, MALDI-TOF MS and 16S rDNA sequencing allowed for the assignment of nineteen of the tested isolates to the species Bacillus pumilus and one to the species Paenibacillus amyloliticus. To the best of our knowledge, this is the first report of soft rot in potato caused by pectinolytic B. pumilus in Tunisia.

Identifying Early-Stage Changes in Volatile Organic Compounds of Ceratocystis fimbriata Ellis & Halsted-Infected Sweet Potatoes (Ipomoea batatas L. Lam) Using Headspace Gas Chromatography-Ion Mobility Spectrometry.

Ceratocystis fimbriata Ellis & Halsted is the pathogen causing black rot in sweet potatoes that can lead to flavor change and toxin release. This study detected the volatile organic compounds (VOCs) of C. fimbriata-infected sweet potatoes in the early stages using headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS). A total of 55 VOCs were identified, including aldehydes, alcohols, esters, ketones, and others. The content of aldehydes and ketones showed a decreasing trend, while alcohols and esters showed an increasing trend. An increase in infection time elevated the content of malondialdehyde (MDA) and pyruvate, while the starch content decreased, the content of soluble protein initially increased, then decreased, and the activities of lipoxygenase (LOX), pyruvate decarboxylase (PDC), alcohol dehydrogenase (ADH), and phenylalanine ammonia-lyase (PAL) increased. The changes in VOCs were closely related to the content of MDA, starch, pyruvate, and the activities of LOX, PDC, ADH, and PAL. Sweet potatoes showed a good discrimination effect by principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) from 0 to 72 h. Twenty-five differential VOCs could be used as early-stage characteristic compounds of C. fimbriata-infected sweet potatoes for early disease monitoring.

First report of Geotrichum candidum causing rubbery rot of potato (Solanum tuberosum) in Michigan.

In April 2018, rotted 'Lamoka' tubers were received from a commercial storage facility (<1% incidence) in St. Joseph County, Michigan by the MSU Potato & Sugar Beet Pathology and Plant & Pest Diagnostics programs. Dense circular colonies of white fungal-like growth were observed on the surface of the tubers, and internal tissues were watery and spongy with gray to brown discoloration (Supplemental Figure 1). Tubers had a strong, sweet alcoholic odor. External and internal tuber tissues were surface disinfested in 0.825% sodium hypochlorite for 1 min, rinsed twice in sterile distilled water, blotted on sterile filter paper, and placed onto 1.5% (w/v) water agar (WA). After 3 days at 21-24°C and ambient light conditions, septate, branched mycelia and hyaline, cylindrical, single-celled conidia 5.2-8.9 µm x 3.6-5.2 µm (n=20 arthrospores) were observed singly or in chains (Supplemental Figure 2A&B). On potato dextrose agar (PDA), colonies were white, circular, and dense (Supplemental Figure 2C). These observations matched morphological descriptions of Geotrichum candidum (Carmichael 1957). No Pythium or Phytophthora spp. were detected. A mono-conidial isolate of the fungus was obtained and maintained on PDA. DNA was extracted from mycelia using a DNeasy plant mini kit (QIAGEN). Fragments of the internal transcribed spacer (ITS) and 18S ribosomal RNA gene regions were amplified using primers ITS1F/4 primers and NS3/8, respectively (White et al. 1990). Purified PCR products (QIAquick PCR purification kit, QIAGEN) were submitted for Sanger sequencing at the Genomics Research Technology Support Facility (East Lansing, MI). The ITS1F/4 and NS3/8 consensus sequences (OP142324 and OP153873) aligned with GenBank accessions of G. candidum KY103456.1 (100% identity) and JF262193.1 (99.75% identity), respectively. Healthy 'Lamoka' tubers were rinsed with tap water, surface disinfested in 0.825% sodium hypochlorite for 15 min, rinsed twice in sterile distilled water, and blotted dry on sterile paper towel. Ten tubers were inoculated by placing 10-mm diameter fully colonized agar plugs, excised from the margin of a 9-day-old PDA culture, onto the surface of each tuber (Duellman et al. 2021). Ten tubers were mock-inoculated using sterile PDA. Tubers were placed in a moist chamber and incubated in the dark at room temperature. After nine days, inoculated tubers exhibited white colony growth on tuber surfaces and an alcoholic scent was present. After 27 days, internal tissues were rubbery, but no discoloration was observed. No rubbery rot symptoms were observed on the control tubers. Samples were excised 1 cm laterally from and vertically beneath the inoculation site. Tissues were surface disinfested as described above and plated on 1.5% WA. After 9 days, a Geotrichum sp. identical to the original isolate was confirmed in 50% of samples from inoculated tubers. No Geotrichum sp. were detected from mock-inoculated tubers. Since 2018, G. candidum has been confirmed in commercial storages in three counties in the Lower Peninsula (incidences up to 1-2%). Geotrichum candidum was recently reported causing rubbery rot of potato in Idaho (Duellman et al. 2021); however, to our knowledge this is the first report of rubbery rot in Michigan. Despite increasing detection frequencies, incidences remain low and spread in storage appears limited. Seed decay leading to stand loss (incidence 1-3%) was observed after planting infected lots, which should be avoided or minimized.

Inhibitory Effect of Potato Sprouting Inhibitor Chlorpropham on Dry Rot

Potato dry rot is one of the potato storage diseases caused by Fusarium species and is a representative pathological disorder that induced post-harvest loss during storage. Chlorpropham treatment for sprouting inhibition is mainly used for room temperature storage of potatoes for processing. In this study, the inhibitory effect of chlorpropham on Fusarium-induced dry rot of potato ‘Dano’. To investigate the mycelial growth rate of the dry rot fungus (Fusarium solani Appel & Wollenw), mycelial growth was investigated in a chlorpropham (5.0, 50.4, 503.8, and 5,038 ppm) and prochloraz (0.1, 1.0, 10.0, and 100.0 ppm) medium containing F. oxysporum mycelia. Mycelia were more inhibited as the concentration of chlorpropham and prochloraz increased during incubation at 20°C, and the inhibition rate was 98.2% and 100% when treated with 503.8 ppm of chlorpropham and 10ppm of prochloraz in 14 days, respectively. Potato Dano tubers inoculated with F. oxysporum were dipped in chlorpropham (5.0, 50.4, and 503.8 ppm) and prochloraz (100 ppm) to investigate the effect of preventing dry rot during cold storage at 20°C and 4°C in vivo. The disease diameter of potatoes stored at room temperature (about 20°C) was reduced to 13.0 mm in the prochloraz 100 ppm teatment, and 10.7 mm in the chlorpropham 50.4 ppm treatment compared to 13.7 mm in the control tuber at 70 days of storage. The disease progression in all treatments including control was similar with no statistically significant difference at 4°C air temperature. From the results of this study, it is considered that treatment with 50.4 ppm of chlorpropham after harvest will be useful for suppressing dry rot of stored potatoes.

Post-harvest sour rot in sweet potato is caused by Geotrichum candidum in Brazil

Post-harvest sour rot in sweet potato is caused by Geotrichum candidum in Brazil

A Novel Based Synthesis of Silver/Silver Chloride Nanoparticles from Stachys emodi Efficiently Controls Erwinia carotovora, the Causal Agent of Blackleg and Soft Rot of Potato.

In recent years, the biological synthesis of silver nanoparticles has captured researchers' attention due to their unique chemical, physical and biological properties. In this study, we report an efficient, nonhazardous, and eco-friendly method for the production of antibacterial silver/silver chloride nanoparticles utilizing the leaf extract of Stachys emodi. The synthesis of se-Ag/AgClNPs was confirmed using UV-visible spectroscopy, DPPH free radical scavenging activity, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). An intense peak absorbance was observed at 437 nm from the UV-visible analysis. The Stachys emodi extract showed the highest DPPH scavenging activity (89.4%). FTIR analysis detected various bands that indicated the presence of important functional groups. The SEM morphological study revealed spherical-shaped nanoparticles having a size ranging from 20 to 70 nm. The XRD pattern showed the formation of a spherical crystal of NPs. The antibacterial activity performed against Erwinia carotovora showed the maximum inhibition by centrifuged silver nanoparticles alone (se-Ag/AgClNPs) and in combination with leaf extract (se-Ag/AgClNPs + LE) and leaf extract (LE) of 98%, 93%, and 62% respectively. These findings suggested that biosynthesized NPs can be used to control plant pathogens effectively.

Identification and characterization of opportunistic pathogen Pectobacterium polonicum causing potato blackleg in China.

Blackleg and aerial stem rot of potato (Solanum tuberosum L.), caused by soft rot enterobacteria of the genera Pectobacterium and Dickeya, has recently increased years in Hebei Province, China. Field surveys were performed during the 2021 potato growing season in Hebei to identify and characterize bacterial pathogens. Sixteen potato plants showing blackleg or aerial stem rot were collected from three potato-producing areas, and ten representative pectinolytic bacteria were isolated from symptomatic plants. 16S rDNA sequencing and multilocus sequence analysis were performed to determine the taxonomic position of the bacterial isolates. The isolates belonged to the genus Pectobacterium, including Pectobacterium atrosepticum, Pectobacterium carotovorum, Pectobacterium brasiliense, and Pectobacterium parmentieri. The exceptions were isolates BY21311 and BY21312, which belonged to a new species of Pectobacterium polonicum previously found in groundwater. The taxonomy of isolate BY21311 was confirmed using whole genome-based analysis. P. polonicum has only been identified in potato plants on one farm in Baoding region in China. Isolates BY21311 and BY21312 displayed similar physiological and biochemical traits to the type strain DPMP315T. Artificial inoculation assays revealed that isolate BY21311 fulfilled Koch's postulates for potato blackleg. These findings represent the first time P. polonicum, a water-associated Pectobacterium species may be the cause of blackleg in the field. Interestingly, P. polonicum BY21311 has reduced ability to macerate potato tubers when compared to P. atrosepticum, P. brasiliense, P. versatile, and P. parvum, which is more virulent in tubers than the type strain DPMP315T. The host range of isolate BY21311 was determined by injection method, which can impregnate five plants. Although the genome of isolate BY21311 harbors gene clusters encoding a type III secretion system, it did not elicit a hypersensitive response (HR) in Nicotiana benthamiana or N. tabacum leaves. T3SS effector AvrE and T4SS effector PilN were obtained by predicting isolate BY21311 genome. P. polonicum appears to show significant variations in gene content between two genomes, and gene content varies between isolates BY21311 and DPMP315T, with strain specific-genes involved in many aspects, including lipopolysaccharide biosynthesis, substrate translocation, T4SS and T6SS among others, suggesting that isolates BY21311 and DPMP315T might represent distinct clades within the species.

ЗАЩИТА КАРТОФЕЛЯ В ПЕРИОД ЕГО ВЕГЕТАЦИИ И ХРАНЕНИЯ

The paper analyzes well-known and new chemical preparations of foreign and domestic production, on the basis of which the justification for the need to develop a new effective domestic preparation for the protec-tion of potatoes during its growing season and storage is given. It is noted that increasing the resistance of potatoes to diseases can be achieved by specialized crop rotations, high-quality varieties, agrotechnical and technological techniques, as well as biological and microbiological preparations, agrochemicals and plant growth regulators. However, the use of only agrotechnical techniques does not provide high protection of potatoes from diseases. Therefore, a new drug "Amophenone" was justified for use, which has a number of advantages over the standard standard tetramethylthiuram disulfide (TMTD). It is shown that "Amophe-non" is highly effective against dry fusarium rot of potatoes, which is confirmed by the experimentally ob-tained results of inhibition of the growth of Fusarium Sambucinum mycelium.

Determination of the severity of soft rot and blackleg caused by Pectobacterium brasiliense in some potato genotypes from Turkey

Pectobacterium species are one of the main bacterial agents of soft rot and blackleg diseases that cause economic damage to potato crops. Farmers around the world suffer losses from both diseases and use different strategies to control. In this study, local potato genotypes were evaluated for disease severity of soft rot and blackleg. We discovered putative genotypes with low disease severity for both diseases. In the tuber experiment, the lowest soft rot was determined for genotype 18 with 34% disease severity. The highest soft rot was found in the cultivars Natasha, Laperla and Sultanecem. In the plant experiment, the lowest lesion length was measured in the cultivars Sultannur, Orchestra and Marabel. The 33% disease severity for these cultivars was also calculated for genotypes 18 and 32. With regard to soft rot and blackleg of potato, this is the first study to determine disease severity of Turkish local potato genotypes.

Phytochemical Screening and Antibacterial Activity of Taxus baccata L. against Pectobacterium spp. and Dickeya chrysanthemi

The yew tree (Taxus baccata L.) is considered in folklore a symbol of immortality due to its qualities of longevity and regeneration. Despite its poisonous reputation, the yew tree has a long history of medicinal use, particularly in the form of extracts from its leaves and bark. In the work presented herein, gas chromatography–mass spectrometry (GC–MS) chemical profiling was applied to the aqueous ammonia/hydromethanolic extracts of several plant organs of T. baccata, leading to the identification of different bioactive compounds than those previously characterized by high-performance liquid chromatography with tandem mass spectrometry (HPLC–MS/MS) in other extraction media. The leaf aqueous ammonia extract was rich in 2-hexylthiophene and 3-O-methyl-d-fructose; 9-octadecenoic and hexadecanoic acid were the main constituents of the bark aqueous ammonia extract; and the fruit hydromethanolic extract contained methyl 2-O-methyl-α-d-xylofuranoside, 1,3-dioxolane derivatives, and erysimoside. The antimicrobial activity of the extracts was assayed against four bacterial pathogens responsible for the soft rot and blackleg diseases of potatoes, viz. Pectobacterium carotovorum subsp. carotovorum, Pectobacterium atrosepticum, Pectobacterium parmentieri, and Dickeya chrysanthemi, resulting in minimum inhibitory concentration (MIC) values as low as 187 μg·mL−1. Bioassays on potato slices confirmed the efficacy of the leaf extract at this dose when applied as a preventive treatment before artificial inoculation with P. carotovorum subsp. carotovorum. In view of this high activity, these extracts may find application in the integrated pest management of soft rot Pectobacteriaceae (SRP) diseases.

Potato bacterial wilt in Ethiopia: history, current status, and future perspectives.

Potato is an essential food staple and a critical tuber crop for rural livelihoods in Ethiopia, where many pathogenic pests are threatening production. Bacterial wilt, also known as brown rot of potato, ranks among the diseases that most affect many potato farmers in Ethiopia and the disease losses dramatically threatening the vibrant potato sector even in the highlands of the country where it has been uncommon so far. To devise a strategy towards boosting potato productivity in Ethiopia where food insecurity is most prevalent, production constraints should be investigated and properly addressed. Hence, we have used existing reviews and reports on the subjects, such as textbooks, and proceeding and conference abstracts in Plant Protection Society of Ethiopia; Web of Science; Google Scholar; Research Gate and CIP's database to document most relevant information on the occurrence, distribution, and disease management of bacterial wilt in Ethiopia. Provision of comprehensive information on potato bacterial wilt occurrence, distribution, and management techniques are crucial for potato growers, researchers and stakeholders engaged on potato industry. In this review, we provided insights on the history, status, and future perspectives of potato bacterial wilt in Ethiopia. Awareness of potato bacterial wilt and integrated disease management approaches could bring a fundamental impact to the farming community mostly to smallholder farmers in developing countries. This document compiled such imperative information targeting bacterial wilt management techniques to ensure food security.

POTENTIALLY DANGEROUS CAUSES OF BACTERIAL DISEASES OF POTATOES IN UKRAINE

An overview of bacterial causative agents of soft (wet) rot of potatoes is given, the epidemiological and etiological aspects of the diseases caused by them are analyzed. When preparing the article, general scientific methods were used: generalization, comparison, system analysis. Data from the European and Mediterranean Plant Protection Organization (EOPO), as well as data from phytosanitary services of EU countries and Ukraine, scientific literature served as material for the analytical study. Trade in plant materials, including potato seed tubers and ornamental plants, is largely responsible for the widespread distribution of pathogens. Locally, pathogens are also spread through plant debris, soil, waterways, aerosols, alternative hosts, and/or farm machinery. The main causative agents of bacterial wet rot of potatoes are gram-negative bacteria of the genera Pectobacterium and Dickeya and quarantine phytopathogens of the genera Clavibacter and Ralstonia. The main methods of detection and identification in asymptomatic potato tubers on an industrial scale are: phytopathological (visual examination of plantations and registration of symptoms of soft rot), microbiological (cultural-morphological and biochemical method, use of test systems for accelerated identification of microorganisms), immunoenzymatic ( enzyme immunosorbent assay), molecular genetic (PCR with specific primers, BIOLOG, DNA fingerprinting and nucleotide sequencing). To date, there are no completely effective pesticides to control all pathogens, so disease control measures will continue to rely primarily on avoiding infection during plant cultivation, and especially during the production of healthy certified seed. For a crop like potatoes, this is primarily based on obtaining bacteria-free minibulbs, applying strict seed certification schemes and strict phytosanitary restrictions. Knowledge of the sources of pathogens and routes of infection should be the basis for the application of phytosanitary measures, especially during and after harvest. Control of quarantine phytopathogens requires special attention. Soft rot pathogens are the main cause of limiting potato production in many regions of the world, particularly Clavibacter michiganensis subsp. sepedonicum and R. solanacearum are quarantine objects of the A-2 list of the European and Mediterranean Organization for Quarantine and Plant Protection. Upon entering our country, R. solanacearum has a high probability of acclimatization and spread in the country.

Prevalence and Eco-friendly Management of Dry Rot of Potato in Rawalpindi and Islamabad

The dry rot disease of potato is caused by Fusarium species is a disastrous disease of potato as postharvest disease that can contribute huge losses of potato during storage. During current study market based survey was done in Rawalpindi and Islamabad during year 2021to estimate the disease prevalence and diseases losses during storage of different potato verities in different months. It revealed that maximum dry rot disease prevalence of potato was 1.90%, 1.86% in Rawalpindi and Islamabad respectively. Fungi isolates were isolated from diseases samples and were preserved and identified on the basis of cultural and morphological keys. The pathogenicity test confirmed the virulence of pathogenic fungal isolates. Among the cultivars, average loss of dry rot of potato within the three months; August and September, October were found in cultivar Kuroda and Lady Rosetta was 1.36% and 1.21% respectively in Rawalpindi while 1.86% and 1.48% average loss was estimated in Kuroda and Lady Rosetta respectively in Islamabad. During disease management studies in which biocontrol agent (Pseudomonas fluorescence, Bacillus subtilis and Bacillus cereus) were used during the dual culture technique and P. fluorescence was found most effective which reduced the 70% growth of fungal isolates and the maximum zone of inhibition 16mm was calculated. These preliminary postharvest disease studies will ultimately a source of information for the researchers and industrialist to develop cost effective and ecofriendly management against dry rot disease of potato during storage conditions.

Biological control of soft rot in potato by κ-carrageenan carriers encapsulated microbial predators.

The Pectobacterium and Dickeya pectinolytic bacteria are phytopathogens responsible for several macerating diseases on a wide range of crops and ornamental plants. Recently, bacterial predators belonging to the Bdellovibrio and like organisms (BALOs) were shown to efficiently prey on these rot-causing bacteria and reduce soft rot-induced potato slice maceration. In the current research, our novel approach aimed at developing and studying a κ-carrageenan-based encapsulation system for fast-release of entrapped B. bacteriovorus HD100 in high numbers to prevent bacterial soft-rot infections. κ-carrageenan-dried carriers swelled and dissolved upon immersion in water due to a loss of potassium ions which are the main cross-linking agents. Survival rates of the predators after drying were higher for immobilized bdelloplasts (e.g., predator inside the host) compared to attack phase (host-searching, AP) cells, and with the addition of the osmoprotectant trehalose to the carriers. Released encapsulated predators preyed efficiently on soft rot bacteria, with bdelloplasts performing better as compared to AP cells. However, predation dynamics were influenced by the type of added osmoprotectant. Carrageenan-trehalose carriers encapsulating predators were able to reduce soft-rot disease in situ using a potato slice assay. To our knowledge, this research is the first to explore the potential of encapsulated BALOs against phytopathogens. KEY POINTS: • Dissolution of the carriers was affected by potassium concentration in the system. • Encapsulation of bdelloplasts with trehalose best maintained the predator viability. • The encapsulated predators efficiently controlled soft rot in vitro and in situ.

Complete Genome Sequence of Brachybacterium sp. Strain NBEC-018, Isolated from Nematode-Infected Potatoes.

Brachybacterium species are ubiquitous Gram-positive bacteria. Here, we report the complete genome sequence of Brachybacterium sp. strain NBEC-018. The strain was isolated from rotten potatoes that were infected with potato rot nematodes (Ditylenchus destructor). The genome sequence will be beneficial to clarify the ecological role of Brachybacterium species.

Pectobacterium versatile Bacteriophage Possum: A Complex Polysaccharide-Deacetylating Tail Fiber as a Tool for Host Recognition in Pectobacterial Schitoviridae

Novel, closely related phages Possum and Horatius infect Pectobacterium versatile, a phytopathogen causing soft rot in potatoes and other essential plants. Their properties and genomic composition define them as N4-like bacteriophages of the genus Cbunavirus, a part of a recently formed family Schitoviridae. It is proposed that the adsorption apparatus of these phages consists of tail fibers connected to the virion through an adapter protein. Tail fibers possess an enzymatic domain. Phage Possum uses it to deacetylate O-polysaccharide on the surface of the host strain to provide viral attachment. Such an infection mechanism is supposed to be common for all Cbunavirus phages and this feature should be considered when designing cocktails for phage control of soft rot.

Protective effect of Bacillus species associated with Rumex dentatus against postharvest soil borne disease in potato tubers and GC-MS metabolite profile.

Potato is constantly exposed to various kinds of phytopathogens which cause diseases during the developmental stage and post-harvest storage. This investigation was designed to assay the anti-phytopathogen activity of bacterial endophytes and their suppressive effects on rot disease in potato. The study also aimed to screen isolates for their plant growth-promoting traits and establish GC-MS-based metabolite profile of the potent isolate. Endophytes were isolated from Rumex dentatus and identified based on 16S rRNA gene. They were screened in dual culture assay against fungal phytopathogens and the potent isolate was tested for its capability to suppress Fusarium rot disease in potato tubers. The mechanism of action of endophytes on the phytopathogens was assessed using scanning electron microcopy. Isolates were also screened in vitro to assay their capability to produce phytohormones, hydrolytic enzymes, and to solubilize phosphates. Endophytic isolates produced proteases with a diameter of halo zone ranging from 7 to 32mm. Bacillus sp. KL5 exhibited the highest production of indole acetic acid (IAA) with the amount of 104.28µg/mL and was the most potent antagonist of Fusarium oxysporum and Verticillium dahliae with an inhibitory percentage of 61.53 and 100%, respectively. It showed a reduction of potato rot disease severity by more than 50%. GC-MS of active fractions of KL5 showed the presence of dibutylphthalate and 2,4-di-tert-butylphenol as major metabolites. From this study, it is evident that endophytic Bacillus species from R. dentatus are potent antagonists of F. oxysporum and V. dahliae. Bacillus sp. KL5 is a potent inhibitor of pathogenic F. oxysporum in potato tubers and can be developed as a biocontrol agent.