Ring Rot Infection Research Articles

Pouteria caimito fruit derived nanoparticles inhibited the apple ring rot disease as well as extended the shelf-life of sliced apples

BackgroundApple disease, exaggerated by Botryosphaeria dothidea, is a foremost intimidating problem for extending the apple fruit shelf-life and producing substantial economic losses for cultivators and distributors. Alternate sources are urgently needed to prevent or inhibit the ring rot infection of apple fruit instigated by Botryosphaeria dothidea ObjectiveIn this current study, we premeditated to make novel organic nanoparticles as of Pouteria caimito fruit extract and calcium chloride (PCNP), which were used to evaluate the preventive outcome of Botryosphaeria dothidea-caused apple disease on postharvest apple fruits. ResultsOur findings corroborated that the fruit derived nanoparticle had been confirmed for quality and size by altered estimations such as fourier transform infrared (FTIR), UV–vis spectroscopic analysis, scanning electron microscope and energy dispersive X-ray (SEM and EDX) estimation, and dynamic light scattering (DLS) analysis. In addition, we have investigated the excellent inhibitory action of the pathogen infection in apples initiated by Botryosphaeria dothidea. The protective enzymes function was pointedly improved in nanoparticle-treated apple fruits once equated with those of control apple fruits. The catalase (CAT) and superoxide dismutase (SOD) activities were pointedly improved in nanoparticle-treated fruits when compared to those of control fruits. The shelf-life extension studies were conducted for 7 days with a fresh-cut apple. The total soluble solid, pH, weight loss, and sensory studies were analyzed, and they proved the extension of sliced apple shelf life up to 7 days. ConclusionsThe discoveries of this study provided a well-organized, harmless, and environment-friendly substitute to control the apple disease as well as the durability postponement of sliced apples 7 days or may longer.

The Efficacy of the Turmax Drug for Cultivating Potatoes under the Conditions of the Tomsk Oblast

The paper presents the results from field trials of Turmax organomineral supplements. The goal of the study was to investigate the effect of this drug on increasing potato yields and reducing the incidence of potato diseases. The object was the Turmax drug, which includes the basic mineral nutrients and metabolic products of rhizospheric microorganisms. The tests were carried out with the cultivation of Nevsky potatoes for 4 years with different weather conditions on gray forest soil. Test options included control, a single spraying of potato plants by Turmax on seedlings and in the budding phase, and two-time spraying of plants on seedlings and in the budding phase. The results of the study showed that double processing of potatoes was the most effective in different weather conditions—for seedlings and before flowering. Potato yield increased by 21–40% in different years. This treatment not only significantly increased the potato yield but also decreased the incidence of their fungal (late blight, rhizoctonia, common scab) and bacterial (bacterial rot, wet rot, ring rot) infections.

Apple ring rot-responsive putative microRNAs revealed by high-throughput sequencing in Malus × domestica Borkh.

MicroRNAs (miRNAs) are small non-coding RNAs, which silence target mRNA via cleavage or translational inhibition to function in regulating gene expression. MiRNAs act as important regulators of plant development and stress response. For understanding the role of miRNAs responsive to apple ring rot stress, we identified disease-responsive miRNAs using high-throughput sequencing in Malus × domestica Borkh.. Four small RNA libraries were constructed from two control strains in M. domestica, crabapple (CKHu) and Fuji Naga-fu No. 6 (CKFu), and two disease stress strains, crabapple (DSHu) and Fuji Naga-fu No. 6 (DSFu). A total of 59 miRNA families were identified and five miRNAs might be responsive to apple ring rot infection and validated via qRT-PCR. Furthermore, we predicted 76 target genes which were regulated by conserved miRNAs potentially. Our study demonstrated that miRNAs was responsive to apple ring rot infection and may have important implications on apple disease resistance.

Susceptibility to Apple Ring Rot Infection of Apple Branches of Different Ages and Preventive Effect of Fungicides on Wart Bark Formation

Susceptibility to Apple Ring Rot Infection of Apple Branches of Different Ages and Preventive Effect of Fungicides on Wart Bark Formation

The role of peroxidases weakly bound to the cell walls in potato resistance to ring rot infection

The role of peroxidases weakly bound to the cell walls in potato resistance to ring rot infection

Evaluation of PCR methods for the diagnosis of bacterial ring rot infections in potato 1

A 434‐bp fragment of Clavibacter michiganensis subsp. sepedonicus DNA was sequenced and four different primers were designed for PCR amplification. PCR products of 200 bp and 300 bp were consistently amplified with genomic DNA of the bacterium. Preliminary specificity experiments indicated that these primers only amplified DNA from the ring‐rot bacterium. Composite 400‐tuber samples were collected from a lot of 20 000 kg of potatoes or individual tuber samples with suspected ring‐rot symptoms. The samples were divided into two parts and parallel tests with immunofluorescence and PCR were done. Potato‐tissue samples for PCR detection were extracted once with 1:1 phenol‐chloroform. The optimal dilution of the sample for PCR‐based detection was 1:10. Altogether 200 samples were analysed by both immunofluorescence and PCR methods. In most cases, the same positive and the same negative samples were revealed. In some cases, PCR revealed the samples with a lower degree of contamination more easily. Positive and negative samples were very easily detected by the PCR‐based assay. Large‐scale specificity experiments will be needed to clarify whether our primers only detected the ring‐rot bacteria and not closely related saprophytic bacteria.

Evaluation of Serological Tests for Detection ofClavibacter michiganensissubsp.sepedonicusin Composite Potato Stem and Tuber Samples

A procedure to index potato seed lots for bacterial ring rot was evaluated by testing composite samples of tissue from 200 potato stems or tubers, in blind experiments, for the presence of Clavibacter michiganensis subsp. sepedonicus by immunofluorescence and enzyme-linked immunosorbent assay (ELISA) in six laboratories. Different antibody preparations were used for the two serological tests. Tissue samples were from ring rot-free potato plants, but ring rot-infected tissue was added to 88 of the 385 composite samples to create authentic positive composites. One laboratory achieved 100% efficiency for detection of ring rot infections in stem samples with ELISA, but the overall sensitivity and specificity of ELISA were 97.7 and 90.1%, respectively, for stems and 93.3 and 86.7%, respectively, for tubers [...]

Biological suppression of potato ring rot by fluorescent pseudomonads.

Three strains of fluorescent pseudomonads (IS-1, IS-2, and IS-3) isolated from potato underground stems with roots showed in vitro antibiosis against 30 strains of the ring rot bacterium Clavibacter michiganensis subsp. sepedonicus. On the basis of morphological and biochemical tests and fatty acid analysis, IS-1 and IS-2 were identified as Pseudomonas aureofaciens and IS-3 was identified as P. fluorescens biovar III. IS-1 was the most inhibitory to C. michiganensis subsp. sepedonicus strains in vitro, followed by IS-3 and IS-2. Suppression of ring rot by these antagonists was demonstrated in greenhouse trials with stem-cultured potato (cv. Russet Burbank) seedlings. Although each antagonist significantly reduced C. michiganensis subsp. sepedonicus populations, only IS-1 reduced infection by C. michiganensis subsp. sepedonicus. In a second experiment, treatment with IS-1 (10(9) CFU/ml) significantly reduced ring rot infection by 23.4 to 26.7% after 5 to 8 weeks. The average C. michiganensis subsp. sepedonicus population was also significantly reduced by 50 to 52%. Application of different combinations of antagonist strains was not more effective than single-strain treatment.

Detection ofCorynebacterium sepedonicum in potato cultivars with different propensities to express ring rot symptoms

Various potato cultivars were grown in field plots from seed pieces inoculated withCoryneacterium sepedanicum by vacuum infiltration. Foliage symptoms were recorded during the growing season and tuber symptoms at harvest. Cultivars were ranked according to the frequency with which the progeny tubers expressed external bacterial ring rot symptoms. Those that yielded 50–100% symptomatic tubers were placed in symptom expression class (SEC) 1; those that produced 25–49%, 10–24%, and ≤9% symptomatic tubers were placed, respectively, in SEC 2,3, and 4. The incidence of latent ring rot infections in stems and tubers were similar among cultivars in the different SEC classes. Bacterial population densities, quantified by immunofluorescence, were as high as 1010 cells/g in stems from cultivars of all SEC classes. Mean populations in tubers ranged from 106 – 107 cells/g and did not differ significantly among cultivars.

Cultivar response to bacterial ring rot infection in Maine

An account of several years of testing cultivars for response to bacterial ring rot (BRR) infection is reported. Inoculum was prepared by grinding infected tuber tissue and adding distilled water to make a slurry. Seedpieces of cultivars to be tested were dipped in the slurry, planted and covered immediately in the field. Five hill plots were arranged in a RCB design with four replications and cultivars of known reaction to BRR were included as checks. Assessment of symptom expressions was begun when symptoms were first observed in any entry and repeated weekly for the remainder of the growing season. Results of tests on named cultivars and a few advanced, numbered selections are presented for the years 1983 through 1986.

Evaluation of immunofluorescence with monoclonal antibodies for detecting latent bacterial ring rot infections

Corynebacterium sepedonicum was detected in symptomless potato stems and tubers with immunofluorescence using monoclonal antibodies specific for the bacterial ring rot pathogen. The concentration of bacterial cells in potato tissue preparations ranged from >500 cells/microscope field to 1 cell per preparation. Symptomless tubers containing ring rot bacteria planted in field plots yielded plants with ring rot symptoms, plants with latent ring rot infections, or plants with no detectable levels of ring rot bacteria. Tubers with the greatest number of bacteria were most likely to develop plants expressing ring rot symptoms, but even some seed tubers with a low number of bacteria developed into plants with symptoms. Some seed tubers with high levels of ring rot bacteria produced plants with only low numbers ofC. sepedonicum.

Volatile monitoring as a technique for differentiating betweenE. carotovora andC. sepedonicum infections in stored potatoes

The volatile production characteristics of ring rot (Corynebacterium sepedonicum) and soft rot (Erwinia carotovora) infected potatoes were investigated under controlled conditions in order to assess the monitoring of volatiles as a technique for differentiating between the infections in stored potatoes. Total volatile production/unit time was much greater from soft rot due to more rapid development after infection. Total volatile production during the period required for the development of the soft rot infection was similar to the output detected during the longer period required for the development of the ring rot infection. The volatile profiles of the two pathogens featured a number of commonly shared metabolites, but one compound was unique to the ring rot infections and two compounds were unique to the soft rot infections. There were also consistent disease-specific changes in the relative concentration of many of the metabolites detected in the volatile profiles.

A method for the detection of latent ringrot in potatoes by immunofluorescence microscopy

A method is described in which the recovery ofCorynebacterium sepedonicum from heel ends of suspected latently infected potatoes is improved by modified extraction and concentration steps. Detection ofC. sepedonicum with the help of indirect immunofluorescence microscopy (IF) is compared with the eggplant challenge test; the use of IF for routine surveys for latent ringrot infection is considered preferable providing that potato extracts are submitted to the eggplant test when IF tests are in doubt.

Nonpathogenic bacteria associated with potato stems cross-react withCorynebacterium sepedonicum antisera in immunofluorescence

Forty-three and 16% of stem smears from ostensibly healthy potato plants tested in 1980 and 1981, respectively, by immunofluorescence usingCorynebacterium sepedonicum antisera, had fluorescing bacterial cells. Eight different bacteria that cross-reacted withC. sepedonicum antisera in immunofluorescence were isolated from stems. Four of these bacteria were Gram negative, three were Gram positive, and one was Gram variable. All bacteria differed fromC. sepedonicum in morphological and biochemical characteristics except the Gram variable bacteria which were morphologically similar toC. sepedonicum at some growth stages. None of the cross-reacting bacteria was pathogenic on eggplant (Solanum melongena L. cv. Black Beauty). Three of the bacteria also formed precipitin bands in double diffusion withC. sepedonicum antiserum. Adsorption of antiserum with any one of the cross-reacting bacteria did not prevent immunofluorescence staining of all the isolated strains. Due to the cross-reactions, reliability of immunofluorescence for detection of latent bacterial ring rot infection was limited

The Detection of Latent Ring Rot (Corynebacterium sepedonicum [Spiek. et Kotth.] Skapt. et Burks.) in Potato Stocks1

AbstractVery low numbers of Corynebacterium sepedonicum (Spiek. et Kotth.) Skapt et Burkh. in potato tubers can be detected by inoculating the bacterial fraction separated from cores (including the vascular tissue) taken from the heel end of tubers into young eggplants (Solanum melanogena). One tuber with simulated latent ring rot infection could be detected readily when mixed with 99 uninfected tubers.

A comparison ofCorynebacterium sepedonicum inocula from resistant and susceptible potato varieties

Experiments were conducted in 1946 and 1947 to determine whether or not ring-rot bacteria,Corynebacterium sepedonicum, from resistant potato seedlings and varieties were more pathogenic than those from susceptible varieties. Bliss Triumph, Burbank, Red McClure and Teton tubers were inoculated, in all combinations, with inocula from ring-rot-infected tubers of the Bliss Triumph, Red McClure and Teton varieties. Resistant seedlings and susceptible varieties were also each used collectively as sources of inocula. Under the conditions of the experiment, the percentage of ring-rot infection and the severity of infection caused by inocula from susceptible varieties was equal to, if not greater than, that caused by inocula from resistant varieties. Plant symptoms developed much earlier in the Bliss Triumph variety than in the Burbank, Red McClure and Teton varieties. Symptoms of ring-rot were slight to absent in the latter variety. In this experiment, the conditions at the Laramie Station (7165 feet elevation) were better adapter for ring-rot symptoms in the plants than at the Torrington Station (4104 feet elevation), although the plant symptoms took a few days longer to become visible at the higher altitude than at the lower one. Microscopic examination of the slides showed that, as an average of all inoculations, far more bacteria were present in the Red McClure, Bliss Triumph and Burbank varieties than were present in the Teton variety. Furthermore, as sources of inocula, the Bliss Triumph tubers produced, on the average, relatively more bacteria in the stems of other varieties tested than either the Red McClure or Teton variety. The results of these experiments show that ring rot bacteria infecting the Teton variety and ring rot-resistant seedlings were not more pathogenic than those carried by susceptible varieties, such as the Bliss Triumph.