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1.
Bison, a new red potato, was introduced by North Dakota State University. This new red variety has smooth tuber type and bright red skin color. Bison yields somewhat less than Norland and Red Pontiac but the advantage of Bison over these two varieties is its uniformity and bright red color. Bison is about medium in total solids and makes chips comparable in color to Norchip but lighter in color than Kennebec. Bison is resistant to race 0 of the late blight organismPhytophthora infestans, but susceptible to race 1–4.  相似文献   

2.
Studies using Paraquat herbicide for early post-emergence control of broadleaved and grass weeds in Katahdin and Russet Burbank potatoes were conducted in Maine during four growing seasons. All rates and times of application of Paraquat gave good commercial control of grass and broadleaf weeds when compared to Premerge and Dowpon treatment as checks. Paraquat applied to Katahdins 2 weeks after ground crack reduced the yield of tubers but did not significantly affect specific gravity. Yield and specific gravity of Russet Burbank was reduced by Paraquat applied one and 2 weeks after ground crack. Paraquat can be used effectively for weed control in Katahdin up to one week after ground crack without crop damage. In Russet Burbank it appeared that application at ground crack was about as late as Paraquat could be applied without affecting yield or specific gravity of tubers.  相似文献   

3.
Roots on potato tubers and stolons displayed the normal root anatomy which consisted of a central vascular cylinder surrounded by endodermis with Casparian strips, the cortex and epidermis. Tuber roots appear to initiate from the parenchyma cells adjacent to the vascular tissue. Shoot tips were similar to normal apical meristems. These observations support our research demonstrating the growth of functional roots from potato tubers and stolons.  相似文献   

4.
Enzyme-linked immunosorbent assay (ELISA), with single or combined antisera was effective for diagnosing potato virus S (PVS), potato virus X (PVX) or both viruses in plants grown in the greenhouse or field. In dormant tubers, stolon, middle and apical end composite sampling with or without eyes and sprouted tubers produced reliable positive assays for PVX. Only tuber pieces with sprouts resulted in consistently reliable assays for PVS. Composite sampling of potato foliage was effective for detecting one PVX infected plant in a total of 100 Kennebec, Norland, or Russet Burbank plants. There were some false negative results and greater variability in composite PVS assays, but on average, one PVS infected plant can be detected in composites of 10 Kennebec, Norland, or Russet Burbank plants. Sodium diethyldithiocarbamate (0.01M NaDIECA) in phosphate buffered saline + 0.5% Tween (PBS-T) added to plant extracts enhanced specific reactions for either virus. Onceor twiceused enzyme conjugate was effective in ELISA of either virus from potato foliage.  相似文献   

5.
Individual unpeeled Kennebec tubers were analyzed after being subdiviled in various ways for sampling. The individual portions were wetashed whith a nitric-perchloric mixture and three cations were determined by Atomic Absorption Spectrophotometry. Representative samples of the tubers could be obtained by using subsamples of a blend or by using two opposite sectors cut longitudinally where each sector comprised 1/16th of the tuber. The latter method gave the greatest uniformity among the subsamples. Magnesium was uniformly distributed in the tubers studied, while calcium and potassium were more concentrated in the area external to the vascular tissue and in the stem and the bud ends of the tubers. The inequality of calcium distribution was extremely great.  相似文献   

6.
Coastal Russet (tested as B9596-2) is a clone with mid-season maturity that produces russet skin tubers that are long and slightly flattened. Tuber yields in the eastern portions of the United States have been considerably greater than for BelRus. Tubers are well-shaped, have shallow eyes, and are attractive in appearance. Tuber appearance and size make this cultivar very well suited for the tablestock market. It is not suitable for processing. Coastal Russet is highly resistant to tuber net necrosis caused by late current season infection with leafroll and is tolerant to common scab.  相似文献   

7.
Potato leafroll virus (PLRV) was purified from potato foliage and stems with an average yield of 0.14 mg of PLRV/kg of potato. Modifications of an existing purification procedure are reported. Five low dosage (38-118 μg of PLRV) intravenous injections were used to produce a PLRV antiserum for use in enzyme-linked immunosorbent assays (ELISA) from tubers. PLRV was readily detected in ELISA testing of potato tubers and leaves and inPhysalis floridana Rybd. Non-specific reactions were low with all tissues. In parallel tests, a Canadian antiserum produced higher nonspecific reactions with tuber and leaf tissue. The results indicated that the use of low dosage-intravenous injections might be necessary methodology for producing PLRV antiserum for use in ELISA diagnostic tests with tuber tissue where high non-specific reactions have been reported.  相似文献   

8.
Tuber resistance toPhytophthora infestans was studied in relation to physiological age in tubers of the cultivars Atzimba, Katahdin, Kennebec, and Sebago. Resistance to race1,2,3,4 was evaluated in freshly harvested tubers, and tubers stored at 5 C for up to 215 days. Atzimba tubers were highly resistant when freshly harvested but became increasingly susceptible as they aged physiologically. Tubers of the other three cultivars were susceptible when freshly harvested and also when aged. Further, 57 tuber selections from among 11 crosses initially gave resistant reactions. However, after storage for six months at 5 C, 26.3% of the selections remained resistant, 22.8% were moderately resistant, 31.6% moderately susceptible, and 19.3% fully susceptible.  相似文献   

9.
A procedure for restriction enzyme analysis of the potato chloroplast DNA (ctDNA) is described. The advantages of this method are: 1) rapid determination of ctDNA type, 2) no ultracentrifugation, and 3) low cost of analyses. This method makes it easy to distinguish the ctDNA types of wild and cultivated potato accessions.  相似文献   

10.
Two methods of determining susceptibility of potato clones to blackspot were compared: (1) bruising by weight dropping and (2) bruising by abrasive peeling. A highly significant positive correlation was obtained between the intensity of enzymatic discoloration following abrasive peeling and the amount of blackspot that developed by weight dropping (r=0.93). Abrasive peeling was more rapid than the weight-dropping method. Tuber samples were abraded 30 sec and the amount of enzymatic discoloration evaluated after 24 hr. The need for individually bruising and hand peeling of tubers was eliminated with this method. Because of the rapidity of the abrasive peeling method, it can be used effectively in potato breeding programs to screen large numbers of clones for blackspot susceptibility. Results indicate that tuber maturity affects enzymatic discoloration and blackspot susceptibility. Immature tubers, dug while the vines are still green, are more resistant to blackspot than mature tubers. Tuber maturity therefore must be considered when screening clones for susceptibility to blackspot.  相似文献   

11.
The monodispersed SiO2 particles with perfect sphericity and desired particle sizes were synthesized by an improved Stöber method. The particle sizes and size distribution of colloidal silica could be regulated by adjusting reaction temperature, reaction time, and the concentrations of NH4OH, H2O and TEOS. Dynamic light scattering particle size analysis and SEM analysis confirmed a narrowly distributed particle size and good sphericity of the synthesized SiO2 nanoparticles. The structural colors of silica/polyethyleneimine (SiO2/PEI) thin film fabricated on polyester fabrics were governed by SiO2 particle size, assembly cycles and viewing angles, and the origin mechanism of the structural colors was based on the thin film interference theory. The resultant polyester fabrics showed vivid structural colors changing with the change in viewing angles, displaying a biomimetic variable coloration effect on textiles.  相似文献   

12.
A method was developed which uses changes in rates of retrogradation measured by a Brabender Amylograph to assess the complexing ability of surfactants for free starch in potato flakes during cooling. The rate of retrogradation was linearly related to surfactant concentration. A Blue Value Index method, adapted from use with cereal flours for determination of starch damage, was used to monitor the amount of free starch created by the required particle size reduction for Amylograph analysis. The change in Blue Value Index was also used to monitor the ability of surfactants to complex free starch and thereby influence potato flake quality. Distilled monoglyceride appeared to be more effective than sodiumor calcium stearoyl–2-lactylate. However, the combination of 0.3% distilled monoglyceride with 0.2% sodium stearoyl–2-lactylate was nearly as effective as 0.5% distilled monoglyceride in terms of free starch complexing ability. Instron back extrusion tests for mealiness of reconstituted flakes were found to be influenced by the level of free starch; therefore, back extrusion data should be accompanied by Blue Value Index data.  相似文献   

13.
Pre-harvest chemical applications significantly reduced populations of viableAlternaria solani spores on the soil surface in the laboratory and field and the infection of potato tubers in the field. Only formaldehyde consistently reduced spore germination and tuber infection in the laboratory and the field but Difolatan 4F, Difolatan 4F + DMSO (dimethyl-sulfoxide), Manzate D, Manzate D + DMSO and sodium hypochlorite often reduced fungus populations significantly. More work is necessary before pre-harvest chemical applications can be recommended for control of early blight tuber decay due to the variable performance of many chemicals and the relatively high cost and corrosiveness of formaldehyde, the most effective chemical in the study.  相似文献   

14.
Dimethyl sulfoxide (DMSO) solubilization of starch from lyophilized potato tissue is equally quantitative and more convenient than solubilization in dilute alkali, especially when analysis of a large number of samples is necessary. Starch extraction with DMSO decreases the handling time of each sample by eliminating sonication, filtration, and centrifugation steps required by the NaOH solubilization technique.  相似文献   

15.
Use of enzyme-linked immunosorbent assay (ELISA) in detecting potato leafroll infections in field grown potato, cv. Russet Burbank, was studied from 1986 to 1988 at Rosemount, Minnesota. The objective was to determine relative reliability of current season foliage ELISA, tuber tissue ELISA, and tuber progeny foliage ELISA. Serological tests were most accurate when foliage of tuber progenies was tested. ELISA underestimated total leafroll infection when current season foliage from the inoculated plant was used, in those plants inoculated during late tuber bulking stage. Current season foliage ELISA tests using newly expanded terminal leaflets were more reliable than were tests using older leaflets. Leafroll infection was detected in the current season foliage and tuber progenies (tuber tissue as well as tuber progeny foliage) of some plants seven days after inoculation. Most current season foliage infections were detected by day 14–28 depending on year. Differences among years were most likely caused by variation in quality of virus source plants and numbers of vectors used in inoculation. ELISA tests on tuber tissue were almost as effective as ELISA tests on tuber progeny foliage in detecting potato leafroll 20 days after inoculation, but ELISA on tuber tissue substantially underestimated infection if plants were sampled earlier. Maximum percent tuber infection occurred 20 days or more after inoculation. Movement of the virus from the inoculated stem to other stems decreased with increased plant age at inoculation. Percent infected tubers declined with increased plant age at inoculation. Action thresholds developed for aphids in managing potato leafroll virus should take into account the temporal change in percent infected tubers.  相似文献   

16.
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17.
The five most important variables encountered in french fry production and texture measurement are: specific gravity, raw potato storage, raw potato firmness, freezing of fried product, and cooling of hot french fry slices. Shear force curves are presented to illustrate the effects of these variables. A double maximum cruts shear peak is exhibited by properly processed french fried potatoes when they are hot. Bursting of the crust is less evident with less desirable fries and with frozen and reheated samples. Shear press punch tests proved to be best for analyzing raw potato firmness. In order to determine and study the texture variations within a potato, Durometer3 tests were conducted on concentric zones and sections from bud to stem end of most firm and least firm raw tubers. Higher resistance to penetration was encountered in the most firm potatoes. Durometer values vary directly with solids within a tuber which can be explained by certain morphological conditions. Because of turgidity, however, solids and Durometer values vary inversely between firm and non-firm tubers. A table is presented which lists the texture inferences derivable from changes which occur in the french fried potato shear force curves.  相似文献   

18.
Dormancy release in potato tubers: A review   总被引：1，自引：0，他引：1  
Dormancy release in potato tubers is reviewed in the context of recent biochemical and physiological research with particular emphasis on describing ambiguities in the literature. A complex picture of dormancy release emerges with hypothetical multiple roles for most major plant growth regulator groups which occur within the tuber. Current literature continues to support the “inhibitor/promoter” hypothesis with the critical events associated with dormancy release involving a shift in the growth regulator ratio in favor of promoters and subsequent establishment of positive feedback between the bud and the mobilized food reserves. Dormancy release by external chemical agents possesses immediate practical applications such as dormancy breaking of seed tubers for export or local use, incorporation into seed multiplication programs and rapid post-harvest disease testing procedures. In addition, research using these chemical agents as experimental probes should prove useful in exploring the control mechanisms associated with dormancy release.  相似文献   

19.
Potato spindle tuber viroid (PSTV) caused albinism in the new growth of Rutgers tomato under continuous light. The albinism response was obtained with 4 isolates causing severe symptoms in tomato and with 1 mild isolate which is normally symptomless. Rutgers tomato inoculated with the 4 severe strains of PSTV developed typical ‘bunchy top’ symptoms in 12 to 16-hr day lengths. Symptoms developed slower and much less distinctly on plants incubated in 6-hr days. New growth in PSTV-infected plants was green in short days (12-hr illumination) and chlorotic to white in continuous light. Infectivities of extracts from white portions of plants were from 3 to 10 times greater than those from green portions of infected plants. Albino symptoms also developed in other tomato varieties when inoculated with PSTV and kept under continuous light. Albinism was most pronounced under continuous light at 30°C, somewhat less intense at 24°, and at 16°, new growth of infected leaves and stems remained green. Albinism did not develop in otherSolanum species which are symptomless hosts of PSTV nor in seedling potato plants grown in continuous light.  相似文献   

20.
Maintaining potato viruses X, S, Y, A, M and leafroll in tissue culture plantlets is a convenient, cost and space effective alternative to the use of greenhouse plants. Of these six viruses, only certain strains of PVX induced symptoms in tissue culture plantlets. Nevertheless, all infected tissue culture plants were found to be more reliable than greenhouse grown plants as virus-infected controls in enzyme-linked immunosorbent assay (ELISA) testing. Another advantage of maintaining viruses in tissue culture plantlets was the elimination of contamination by other viruses or other pathogens. Leaves, stems, and roots of virus infected plantlets were tested separately for antigen levels by ELISA. In these tests, the stems and leaves of all but PVA infected tissue culture plants consistently gave positive ELISA values. In contrast, root tissue from PVY infected tissue culture plantlets was not reliable for PVY detection. In all cases, the viruses detected in the original source material were detected in the resulting tissue culture plantlets.  相似文献   

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