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1.
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   

2.
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   

3.
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   

4.
Summary Plants were grown in the field from seed pieces of potato cultivars injected with ring rot bacteria (Corynebacterium sepedonicum). Symptoms were produced with both 18 and 180 colony forming units (cfu) on cvs Norchip and Red Pontiac and with 180 cfu on cv. Belrus plants. Tuber symptoms were detected in all cultivars except Belrus and Teton. Tuber progeny produced plants that developed top symptoms on all cultivars except those of cv. Nooksack, Russet Burbank, and Teton. Tuber progeny of the second crop produced both plants and tubers with symptoms developing only in the cv. Nooksack. In another 3-year experiment, variability in the disease response of selected cultivars and lines was examined following knife-inoculation of tuber seed with a high level of ring rot bacteria. Significant correlations between top and tuber symptoms were detected, but they were not high enough to make unnecessary the examination of both top and tuber symptoms in ring rot disease selection studies. Contribution no. 3879111  相似文献   

5.
The survival ofCorynebacterium sepedonicum, the bacterial ring rot pathogen, in infected potato stems and on burlap surfaces held at various freezing and above-freezing temperatures was investigated by root-inoculating potato stem cuttings with aqueous suspensions prepared from these materials. Infectious bacteria were recovered from dried Russet Burbank stems held for 44 mo in an unheated machine shed and from dried Warba stems held for 55 mo. Inoculum from dried stems of all cultivars held for 63 mo did not incite symptoms; however, inoculum from Russet Burbank stems incited symptomless infection in 10% of the inoculated plants. This 63-mo survival period exceeds a 26-mo survival period previously reported. Ring rot bacteria survived and remained infectious for at least 18 mo on burlap surfaces subjected to temperatures of ?40° to ?5°C, alternating temperatures of -5° to 5°C, or a constant temperature of 5°C. Inoculum from burlap stored at the lower temperatures caused the most severe symptoms. These results stress the need for keeping crop debris away from potato operations and for using proper decontamination procedures to maintain potato seed stocks free of ring rot.  相似文献   

6.
Foliar treatment of potato (Solanum tuberosum L.) with metribuzin at 0.57–1.0 lb/A caused a necrotic reaction in leaflets of plants infected with potato virus Y (PVY), but not in plants infected with potato virus X (PVX) or potato leafroll virus. Necrosis symptoms resulting from metribuzin-PVY interaction were distinct from symptoms of either PVY infection or of metribuzin injury. This reaction was similar in the Russet Burbank, Lemhi Russet, and Pioneer cultivars. Russet Burbank infected with PVY and PVX, alone or in combination, was treated with metribuzin to study herbicidevirus interaction effects on yield. Secondary PVY infection alone caused a 57% yield reduction, and when combined with PVX caused a 71% yield reduction. Although leaflet necrosis was induced by the metribuzin-PVY combination, there was no significant yield interaction. Results suggest that post-emergence application of metribuzin can be used as an aid for detecting and removing potato virus Y infected plants from potato seed fields  相似文献   

7.
Netted Gem potato plants infected with either the ring rot bacterium (Corynebacterium sepedonicum) or the potato leaf roll virus alone exhibited typical symptoms of the respective diseases. Plants infected with both the bacterium and the virus exhibited severe leaf roll. Typical ring rot symptoms were masked in dual infections, thereby increasing the difficulty in detection of the bacterial disease. The combined yield-reducing effect of the two pathogens was greater than that of the potato leaf roll virus and was similar to that caused by ring rot alone.  相似文献   

8.
The potential of flusulfamide (2’, 4-dichloro- α, α, α, trifluoro-4’-nitro-m-toluenesulfonanilide) as a control agent for bacterial ring rot of potato was evaluated by testing the bactericidal activity of this compound against the causal agent,Clavibacter michiganensis subsp.sepedonicus inin vitro tests, followed by greenhouse and field trials involving treatment of inoculated seed tubers. In thein vitro tests, significant reduction in the size and number ofC. m. sepedonicus colonies was observed with complete inhibition of growth occurring at flusulfamide concentrations of 100 mg/1 or greater. In the greenhouse and field trials, tubers of potato cultivar Russet Burbank were inoculated with the causal organism of bacterial ring rot,C. m. sepedonicus, in one of three different ways (cutting, dipping, injection) and subsequently treated by dipping in an aqueous solution containing varying concentrations of flusulfamide. The “dip” and “cut” methods of inoculation were intended to simulate transmission that would occur during normal production practices, while the “inject” treatment was intended to assess the effect of flusulfamide on existing infections. In both the greenhouse and field experiments, foliar disease incidence and infection rates were reduced, but not eliminated, in plants that were inoculated by cutting or dipping and treated with flusulfamide, whereas plants that had been inoculated by injection showed little effect of treatment with flusulfamide. Based on the results of these experiments, flusulfamide appears to have protective rather than curative properties againstClavibacter michiganensis subsp.sepedonicus.  相似文献   

9.
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10.
Management practices for the suppression of Verticillium wilt of Russet Burbank potato include sanitation, use of optimum sprinkler-irrigation practices, soil solarization, and an adequate soil fertility program. Among all cultural factors considered, nitrogen (N) deficiency in potato tissue was most commonly associated with the severity of Verticiilium wilt in Russet Burbank potato. Field studies have shown that increased N availability suppresses Verticiilium incidence on cv Russet Burbank while having no effect on cv Norgold Russet. Studies from both greenhouse and field show that the colonization ofV dahliae in potato stem tissue is suppressed in cv Russet Burbank when the availability of Phosphorous (P) is increased to the optimum. Following one season of cropping with Russet Burbank potato, the treatment providing the optimal N availability also suppressed the increases ofV dahliae populations in the soil during the following year of consecutive cropping. Similarly, after two seasons of continuous potato cropping, treatments with optimal P had lower soil populations ofV. dahliae in soil. Results show the suppression of Verticiilium wilt with optimal fertility. Verticiilium wilt [caused by eitherVerticiilium dahliae Kleb, (microsclerotial form) orVerticiilium albo- atrum Reinke and Berthold (dark mycelial form)] is one of the most severe diseases of potato in the United States. Potato yields, tuber size, and specific gravity may be substantially reduced by this disease, depending on severity, time of occurrence, and growing season. In Idaho and other arid growing regions of the United States, Verticiilium wilt is caused byVerticillium dahliae Kleb. Idaho field studies involving cropping practices, soil fumigation treatments, solarization, and Verticillium-resistant potato clones all support the importance ofV dahliae upon potato yield. Data from these studies show that yield losses due toV. dahliae commonly approximate 5 to 12 metric T/ha (5, 6). Table 1 illustrates the effect of several cropping practices upon relativeV dahliae populations in soil with the effects upon both disease severity and potato yield. With continuous cropping of Russet Burbank,V dahliae populations in soil increased, and yields were reduced by 18 to 19 metric Tlha when compared to locations that had been allowed to remain either weed-free and fallow or where corn had been previously cropped. It was estimated thatV dahliae was influencing yield by about 10 to 12 metric Tlha based on a regression analysis of yield as a function ofV dahliae populations in soil. Similarly, whenV dahliae was suppressed by fumigation treatments involving mixtures of dichloropropene and picfume, yields more significantly increased by 6.5 to 12 metric T/ha (5). Although many factors may influence yields, clones with higher Verticillium resistance than Russet Burbank generally out-yield Russet Burbank. Figure 1 demonstrates the effect of solarization (a technique involving the laying of clear plastic on soil for the purpose of elevating soil temperatures to killV dahliae). When Verticillium was controlled in this manner (lo), there was no significant yield difference between the Russet Burbank potato and the highly resistant A68113-4 clone. The A68113-4 clone grown in non-solarized soil out-yielded the Russet Burbank in non-solarized soil by 31 percent while the solarization treatment significantly increased yield for the Russet Burbank and A68113-4 clones by 46 and 18 percent, respectively. These yield responses were observed in a field where inoculum levels ofV dahliae were relatively low (2.10 cfulgrn of soil). With these losses, the need to develop control procedures is great and to achieve this control the need also exists to accurately evaluate the effect of treatments uponV dahliae. Our Idaho studies have routinely utilized such a procedure (9) in combination with comparisons of both disease severity and yield.  相似文献   

11.
Teton Russet is an early-maturing, medium-russeted, potato cultivar with high merit for both fresh-pack and processing. In early harvest trials in the Pacific Northwest, Teton Russet had total yields similar to Russet Norkotah, and higher than Ranger Russet and Russet Burbank. Marketable yield of Teton Russet in the early harvest trials was also comparable to or higher than Russet Norkotah in Washington and Oregon, and higher than Ranger Russet and Russet Burbank at these sites, as well as in Idaho. In full-season trials, while total yield of the earlier-maturing Teton Russet tended to be lower than Ranger Russet and Russet Burbank, marketable yield was generally higher than Russet Burbank across the majority of sites due to its higher percentage of U.S. No. 1 tubers. Teton Russet is suitable for processing, with acceptable fry color following up to 8 months of storage at 8.9 °C. Uniformity of fry color was also very consistent. Teton Russet has shown lower levels of the amino acid asparagine relative to Ranger Russet and Russet Burbank which may contribute to lower acrylamide levels in French fries and other processed potato products. Teton Russet is notable for having resistance to common scab (Streptomyces spp.) and Fusarium dry rot, and is moderately resistant to tuber net necrosis. Analyses have also shown Teton Russet to have significantly higher protein levels than Russet Norkotah, Ranger Russet, and Russet Burbank, as well as higher vitamin C content than Russet Norkotah and Russet Burbank. Teton Russet was released in 2011 by the USDA-ARS and the Agricultural Experiment Stations of Idaho, Oregon, and Washington, and is a product of the Pacific Northwest Potato Variety (Tri-State) Development Program.  相似文献   

12.
Some of the factors that affected ring rot development in potato plants grown from stem cuttings and root-inoculated withCoryncbacterium sepedonicum were investigated. Isolates ofC. sepedonicum cultured and stored for a, year on agar media were as virulent as those that had been cultured for almost 5 months. Isolates cultured for periods over 2 years gradually lost their virulence; however, decline in virulence was not as rapid as had been previously reported. One isolate became more virulent by inoculating and recovering it from a susceptible potato plant. Ring rot symptoms developed more rapidly in the cultivar Red Pontiac than in the cultivar Netted Gem; however, disease severity eventually reached the same level in both cultivars. The more mature the plants were when inoculated, the greater was the rate of ring rot development. Duration of exposure of wounded roots to inoculum of the pathogen did not affect disease development. No ring rot bacteria were recovered from plants originating from apical cuttings of ring-rot-infected potato plants that exhibited partial wilting. By this technique, plants infected withC. sepedonicum were freed from this pathogen quickly and effectively.  相似文献   

13.
Eradicating potato viruses X and S from Netted Gem (Russet Burbank) and White Rose potatoes increased their yielding potential by 11 to 38% in British Columbia, Oregon and California but there was no yield increase in Washington. The virus-free plants produced 10 to 32% more tubers than infected ones.  相似文献   

14.
Ranger Russet, a new full-season potato variety, was jointly released to growers by the U.S. Department of Agriculture and the Agricultural Experiment Stations of Idaho, Oregon, Washington, and Colorado on May 14, 1991. Ranger Russet was tested in irrigated performance trials in the Western U.S. since 1979. It produces a large yield of high quality, long, russet-skinned tubers that are well suited for baking and processing into french fries. Ranger Russet is more resistant than Russet Burbank to Verticillium wilt, viruses X and Y, leafroll net necrosis, and Fusarium dry rot. It is highly resistant to hollow heart.  相似文献   

15.
Millennium Russet is a medium-late variety with long tubers having light russet skin and white flesh. It has potential as a fresh market and processing (french fries) variety. The tuber type of Millennium Russet is similar to Russet Burbank, but with better external and internal quality. The marketable yield, tuber set, and specific gravity are higher than Russet Burbank. Tubers show good fry color when processed from cold storage (7.2 C). Millennium Russet has a bland flavor and is less mealy and discolored than Russet Burbank. Chemical maturity of Millennium Russet occurs at approximately the same time as Russet Burbank, but it has lower sucrose levels in the bud and stem end. The glucose levels of Millennium Russet were 50% less than Russet Burbank throughout the first 4 months of storage at 10 C. Low glucose levels in the stem end of Millennium Russet when processed out of storage suggest tolerance to stress and low vulnerability to sugar end. Millennium Russet is resistant to common scab and corky ring spot, moderately resistant to dry rot, pink rot, and black scurf, and moderately susceptible to Verticillium wilt, bacterial wilt and brown rot. Millennium Russet is more sensitive to blackspot bruise than Russet Burbank, but more resistant to shatter bruise. Tuber yield of Millennium Russet was less responsive to nitrogen rates when compared with Russet Burbank, but tuber size distribution was more responsive to increases in in-row spacing.  相似文献   

16.
The transmission of PVS by the cutting knife in potato cvs Norland, Kennebec and Russet Burbank was studied in the field and greenhouse. Field studies showed transmission to Norland via tuber infection was significantly less than for Kennebec and Russet Burbank (P = 0.01). However, significant cultivar differences were not found in the greenhouse (P = 0.05). Contamination of the cutting knife by cutting through sprouts resulted in significantly greater numbers of plants infected for cv Kennebec than when sprout contact was avoided (P = 0.05). Although the same trends were observed for cv Norland and Russet Burbank the differences were not significant (P = 0.05). Infectious PVS particles were readily recovered from materials commonly contacted during potato cultivation, storage and processing. Retention time of infectious PVS was usually greater when materials were held at 4°C and 100% relative humidity than at ambient greenhouse conditions. Retention times ranged from 0 hr (PVS not recovered) to 180 hr on unpainted wood. Results demonstrated the need for strict indexing and sanitation procedures during the production of PVS-free potato seed.  相似文献   

17.
A polymerase chain reaction (PCR)-based test for potato late blight (Phytophthora infestans) and pink rot (P.erythroseptica, P. nicotianae) diseases has been developed for use with potato tuber tissue. Primers based on sequence analysis of the ITS2 region of ribosomal DNA of late blight and pink rot pathogens were utilized in PCR assays of inoculated tubers and tubers harvested from plots known to have late blight and/or pink rot. Assays of artificially inoculated Kennebec and Russet Burbank tubers revealed thatP. infestans was detected by PCR as early as 72 h after inoculation and in the absence of visible symptoms. Much higher detection frequencies were obtained by PCR compared with plating on selective medium or placement of tissue in moist chambers. Tubers from plots known to have late blight and/or pink rot were tested using the PCR assay. Assay of late blight lesions showed ca. 80% recovery for late blight-infected tubers from the field. Results indicate that the PCR assay provides a rapid and accurate test for diagnosis of late blight and pink rot in potato tubers.  相似文献   

18.
Symptomatically distinct isolates of potato leaf roll virus were transmitted from White Rose to Russet Burbank potato by aphids and by grafting, from White Rose potato toP. floridana by aphids, and fromP. floridana toP. floridana by aphids. Isolates from White Rose potato generally produced stable and characteristic secondary leaf roll symptoms (but not primary leaf roll symptoms) when transmitted to Russet Burbank potato but variable symptoms when transmitted toP. floridana. Isolates from two of the latter plants with moderate and severe symptoms generally incited stable and characteristic symptoms when transmitted to otherP. floridana plants. The stable symptoms produced by each of these isolates were not modified by infestingP. floridana plants with varying numbers of viruliferous aphids. The results obtained in this study corroborate previous evidence for the existence of strains of potato leaf roll virus. It is suggested that certain White Rose potato plants contained mixtures of leaf roll virus strains. Furthermore, it is postulated that these mixtures were at least partially separated by “natural” selection following transmission toP. floridana. This mechanism provides an explanation for the stable symptoms produced by isolates transmitted fromP. floridana toP. floridana.  相似文献   

19.
Pacific Russet is a high-yielding, early maturing, oblong russet fresh market cultivar with excellent tuber appearance and culinary quality. In trials conducted in western Canada the yield of the new cultivar was generally superior to Russet Burbank, Ranger Russet, and Atlantic at 80, 90, and 110 days after planting. In the North Central Regional Variety Trial the yield of Pacific Russet exceeded that of Russet Norkotah in four of the eight sites in 2000 and three of the eight sites in 2001. In trials conducted in Ontario (Canada) Pacific Russet exceeded the yield of Goldrush at both sites in 2001 and in 2002 at two of the three sites that included both cultivars. External and internal defects occur at very low levels. The new cultivar is resistant to common scab and moderately resistant to Verticillium and Fusarium wilt, but susceptible to Fusarium dry rot and late blight (foliar). Pacific Russet shows clear foliar but not tuber symptoms when infected with bacterial ring rot.  相似文献   

20.
Alta Russet (Russet Nugget × Ranger Russet) is an early-maturing cultivar, with high yield and excellent processing quality (fry color and dry matter) coupled with a tuber size and shape profile ideal for the manufacture of wedge-cut french fries. In the western Canadian regional trials harvested 110 days after planting, the yield of the new cultivar was similar and the specific gravity superior to that of Russet Burbank. In multi-harvest date trials conducted under irrigated conditions in southern Alberta (Canada) the yield of Alta Russet was superior to Russet Burbank and Shepody and similar to Ranger Russet (Amisk) when harvested at 95 and 110 days after planting. The tuber specific gravity of the new cultivar was superior to Russet Burbank, Shepody, and Ranger Russet (Amisk) at 95 days after planting. At 110 days after planting tuber specific gravity was similar to Ranger Russet (Amisk), but superior to Russet Burbank and Shepody. Fry color was generally superior to Russet Burbank in the western Canadian regional trials and in the multi-harvest trials was generally similar to Russet Burbank, Shepody, and Ranger Russet (Amisk). Alta Russet produces excellent fry color out of long-term storage at 8 C and acceptable color at 6 C. External and internal defects occurred at very low levels in all trials. Alta Russet is resistant to common scab and Verticillium wilt, moderately resistant to early blight and Fusarium wilt and susceptible to Fusarium dry rot and late blight. The new cultivar shows clear symptoms when infected with bacterial ring rot.  相似文献   

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