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1.
Antisera specific forCorynebacterium sepedonicum were produced in three rabbits and in a goat. Bacterial cell agglutination titers of 640, 1280, and 1280 were recorded for the rabbit sera and 320 for the goat antiserum. All antisera reacted equally well with twelve isolates ofC. sepedonicum obtained from Canada, California, Montana, Oregon, Washington, and Wisconsin. No cross-reactivity was observed when the anti-C. sepedonicum sera were tested against five otherCorynebacterium spp.and seven other species of plant pathogenic bacteria. Using the antisera collected from rabbits, an effective and reliable agglutination test was developed for the detection ofC. sepedonicum in potato stem and tuber tissue. Extracts from tubers affected by other maladies incudingErwinia spp. (soft rot),Fusarium spp. (dry rot),Phytopthora erythroseptica (waterrot),and Pythium debaryanum (leak) or tubers otherwise free fromC. sepedonicum infection did not produce an agglutination reaction when tested with anti-C. sepedonicum serum.  相似文献   

2.
The indirect fluorescent antibody staining (IFAS) procedure was successfully used in place of the Gram stain procedure to confirm diagnosis of bacterial ring rot. Antisera produced against untreatedCorynebacterium sepedonicum cells, glutaraldehyde-fixed cells, heat-treated glutaraldehydefixed cells, and a cell extract had useful IFAS titers and similar specificity. Optimum antiserum dilution was critical for a reliable test; at high antiserum dilution optimum antigen excess caused poor staining, while at low antiserum dilution non-specific reactions occurred. Although the IFAS procedure was useful as a confirmatory test, its realiability as a diagnostic test is seriously questioned.  相似文献   

3.
A nonfluidal strain (SSNF50) ofCorynebacterium sepedonicum (=Clavibacter michiganense subsp.sepedonicum) was isolated from potato (Solanum tuberosum) stems from Idaho. A precipitin band common to other strains was not detected in Ouchterlony double diffusion (ODD) tests of SSNF50. SSNF50 was indistinguishable from fluidal strain SS20 ofC. sepedonicum with respect to latent period in eggplant or potato, reaction in latex agglutination and fluorescent antibody stain, and level of population in infected potato stems. Latent period of infection in potato from nonfluidal strain SSNF201, isolated in the laboratory from a culture of fluidal strain SS20, was longer than that of SS20 or SSNF50 despite similar pathogen population levels. A precipitin band common to ODD tests of SS20 and SSNF50 was not detected in tests of SSNF201. SSNF50 is the first nonfluidal strain ofC. sepedonicum to be isolated from potatoes.  相似文献   

4.
The latex agglutination test was evaluated for detection of the potato bacterial ring rot pathogen,Corynebacterium sepedonicum. The bacterium was detected in infected potato stems and tubers tested and in inoculated eggplant stems. Test reliability was confirmed using blind tests. A minimum of 106 bacterial cells/ml was requisite for observable agglutination. Nonspecific reactions were not observed from healthy extracts of plant tissues. Nonspecific reactions with other bacteria maintained in pure culture were eliminated by addition of bovine serum albumin to sensitized latex preparations.  相似文献   

5.
Field experiments were designed to subject Superior potato plants to various levels of defoliation by the Colorado potato beetle (CPB)Leptinotarsa decemlineata (Say), Coleoptera: Chrysomelidae. Defoliation occurred during each of five consecutive plant growth periods and CPB population, plant leaf area, and tuber weight data were recorded for each period. A visual defoliation rating scheme provided an accurate estimate of actual potato plant leaf area of defoliated plants. Data generated from regression analysis demonstrated a significant dependence of leaf area on CPB numbers per plant during some plant growth periods, but numbers of CPB accounted for very little of the total variation in tuber weight. Plant leaf area was the most important independent variable in the tuber weight regression model.  相似文献   

6.
Apical stem cuttings removed from potato plants (cv. Russet Burbank) infected withCorynebacterium sepedonicum and expressing mild symptoms of bacterial ring rot were demonstrated to be free from the pathogen. This material remained free of ring rot through two additional stem cutting generations and when grown in the field for four successive tuber generations.  相似文献   

7.
In two greenhouse tests, we compared cell populations ofCorynebacterium sepedonicum in inoculated cultivars which had failed to show symptoms in field inoculation tests against cultivars that produce well-defined symptoms. Both population studies showed that cell numbers as high as 1 × 109 colony-forming units per gm of fresh weight (cfu gm-1) were reached in some cultivars prior to symptom development. In one of these tests, conducted when day length averaged 14 1/2 hrs, some cultivars failed to show symptoms 11 wks after inoculation but were found to have cell populations as high as 3.2 × 108 cfu gm-1 7 wks after inoculation. In another study, root and seed piece inoculations were compared in susceptible and resistant cultivars and only minor differences in symptom expression due to mode of entry of the pathogen were found.  相似文献   

8.
Small field plots of Katahdin potatoes on Long Island, NY were treated 6 times in 1980 for control of Colorado potato beetle (CPB)Leptinotarsa decemlineata (Say), Coleoptera: Chrysomelidae, using either the entomogenous fungusBeauveria bassiana (Balsamo) Vuill. (Bb) at 5x 1013 colony forming units/ha or fenvalerate at 0.227 kg active ingredient/ha. No significant differences were found between Bb and fenvalerate treatments in egg mass size and viability or in the total foliage consumed by first generation CPBs. First generation CPB larval populations were significantly higher in Bb plots. Oviposition by first generation adults and second generation beetle populations were higher in fenvalerate plots. Average yield was 29.4 metric tons/ha in fenvalerate plots and 24.6 metric tons/ha in Bb plots (a 16% reduction), but nearby untreated plots were completely defoliated by July 24 and yielded <7 metric tons/ha (> 60% reduction).  相似文献   

9.
An enzyme which hydrolyzed a terminal rhamnose moiety from α-chaconine was extracted and partially purified from Colorado potato beetle (CPB) (Leptinotarsa decemlineata) larvae. This ammonium sulfate precipitated enzyme fraction resulted in nearly 97% metabolism of α-chaconine after a 144 hour incubation period at 42 C as determined by high performance liquid Chromatographic (HPLC) analysis. Approximately 81% of the metabolized α-chaconine was detected asβ 2-chaconine. The isolated enzyme fraction from CPB larvae exhibited no metabolism of α-solanine. Metabolism was also followed over time by thin layer chromatography (tlc).  相似文献   

10.
Quantitative differences among strains ofCorynebacterium sepedonicum (Spieck. and Kotth.) Skapt. and Burkh. (=Clavibacter michiganense subsp.sepedonicum) were distinguished in eggplant (Solanum melongena L. ‘Black Beauty’) bioassays with a simple leaf axil inoculation technique. Latent period of infection (time from inoculation to first appearance of symptoms) varied inversely with inoculum dose. Latent period of infection varied significantly among strains ofC. sepedonicum. Symptoms developed more rapidly in plants grown under controlled conditions in a growth chamber than those grown in a greenhouse. Plants treated with inoculum prepared from broth cultures exhibited symptoms more rapidly than those treated with inoculum grown on agar.  相似文献   

11.
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.  相似文献   

12.
Summary Apical explants from sprout tissue, cultured in vitro, of potato tubers (cv. Russet Burbank) infected withCorynebacterium sepedonicum were demonstrated to be free of the pathogen. The material remained free of the pathogen through three in vitro generations and through two tuber generations produced from the in vitro plantlets. Contribution 3878878.  相似文献   

13.
The potential of the flowering tobacco,Nicotiana alata, to sustain the survival and the development of the Colorado potato beetle (CPB) was assessed. We made food preference, larval development and rearing tests in relation with other plant species, specially with potato. In spite of a clear preference of the CPB for potato, the insects could complete a full life cycle on the flowering tobacco. In comparison with CPBs on potato, those on the flowering tobacco had a slight delay of two days in their development, beginning when larvae reached their tenth day. CPBs on the flowering tobacco had a much lower survival rate (14.0% against 66.7%) and adults were smaller (100.9 mg against 133.0 mg). Nevertheless, the flowering tobacco is the firstNicotiana species which is an acceptable alternative host for the CPB, and could facilitate the survival and the distribution of the insect.  相似文献   

14.
Fifty-seven tuber-bearingSolanum progenies including species and interspecific hybrid derivatives were evaluated for resistance to green peach aphid (GPA),Myzus persicae (Sulzer), using an excised leaflet test. The progenies segregated for resistance and most contained some highly resistant clones. Resistance appeared to be partially dominant and genotype-environment interaction was low. Heritability estimates of 50–60 percent were obtained from both diploid and tetraploid populations.  相似文献   

15.
One hundred and fifty-six plant accessions, including susceptible checks, from the IR-1 collection were evaluated for resistance/immunity to bacterial ring rot (BRR). Each accession selected had been previously rated as highly resistant to BRR based on symptom expression but, in our tests, 57 of them yielded no plants which failed to produce symptoms. However, the remaining 99, represented by a total of 2589 inoculated plants, yielded 1000 plants which failed to produce BRR symptoms after eight weeks. Immunofluorescent antibody stain testing showed that 679 of the symptomless plants supported detectable numbers ofCorynebacterium sepedonicum cells. Comparison of root-inoculated and tuber-inoculated accessions showed that root-inoculations yielded significantly fewer symptomless and bacterial cell-free plants. No significant differences were found in BRR reactions of fiveSolanum spp. when inoculated with two different strains ofC. sepedonicum. Appreciable numbers of symptomless plants were obtained from inoculated progeny of crosses with resistant cultivars but none of those retested proved to be immune.  相似文献   

16.
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  相似文献   

17.
The ring rot bacterium,Corynebacterium sepedonicum (Spieck. and Kotth.) Skapt. and Burkh. [Clavibacter michiganense subsp.sepedonicum (Spieck et Kotth.) Davis et al.], and latent potato viruses (potato virus S and potato virus X) were investigated for their effect on atypical (ATYP) ring rot symptom development on Russet Burbank potato plants at different temperatures. Plants grown at 21 C from stem cuttings root-inoculated withC. sepedonicum developed typical wilting and chlorotic symptoms of ring rot that were equally severe on virus-free (VF) and virus-infected (VI) plants. All VF and VI plants grown at 15 C from inoculated stem cuttings exhibited ATYP symptoms that included extreme stunting, resetting, and chlorotic symptoms of ring rot. More severe ATYP symptoms developed on VI than on VF plants. Up to 5 wk after inoculation withC. sepedonicum, ATYP symptom severity ratings of both VF and VI plants increased and declined thereafter. The ATYP severity ratings were highly correlated with fresh weight of plants with high severity ratings being associated with low fresh weights. These results emphasize the need to determine the role of temperature and viral pathogens on ring rot symptomology in existing and newly developed potato cultivars and thereby enable better field detection of bacterial ring rot.  相似文献   

18.
The survival of the ring rot bacterium,Corynebacterium sepedonicum, on contaminated surfaces and in infected stems was investigated by root inoculating potato stem cuttings with aqueous suspensions prepared from these materials. The pathogen survived for 24 mo on contaminated surfaces of burlap, kraft paper, and polyethylene plastic held at 12% relative humidity (RH) at either 5 or 20°C. It persisted for less than 14 mo on surfaces held at 94% RH at either temperature. Infectious ring rot bacteria were also recovered from dried, infected potato stems held for 26 mo in an unheated machine shed. These results emphasize the importance of strict sanitation and disinfestation procedures in maintaining potato seed stocks free of bacterial ring rot.  相似文献   

19.
Bacterial ring rot-infected tuber and stem tissue reacted withCorynebacterium sepedonicum antiserum in agar immunodiffusion (AID). The AID test was as effective as immunofluorescence (IF) in confirming ring rot in potato tubers submitted for diagnosis. Precipitin bands developed in AID with tuber preparations that contained, in a 1:10 dilution of the preparation, at least 100 IF positive cells/microscope field with a 100 X oil objective. Only a low percentage of preparations with less than 100 IF positive cells were positive with AID. Samples inoculated withC. sepedonicum strains which produced non-mucoid colony types on YGM medium did not consistently develop precipitin bands in AID which suggests that the usefulness of the test may be limited where non-mucoid strains occur naturally.  相似文献   

20.
《Crop Protection》1988,7(1):62-65
Three green peach aphid (GPA) strains, Myzus persicae (Sulzer) (Homoptera: Aphididae) obtained from New York, Puerto Rico and Minnesota, were reared on resistant potato hybrid D888-4 and a susceptible cv. Red Pontiac. No significant differences in GPA mortality were observed when aphids were reared on either the resistant or susceptible potato cultivars and later exposed to methamidophos 4EC, pirimicarb 50 WP, azinphos-methyl 2EC or permethrin 2EC. The interaction between the four insecticides × three GPA strains was significant. Of the three aphid strains, those from Minnesota had the lowest susceptibility to permethrin, pirimicarb and azinophos-methyl. No mortality was observed in this GPA strain when tested with azinphosmethyl.  相似文献   

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