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1.
The effects of sulphur dioxide (SO2) and nitrogen dioxide (NO2), singly and in combination, on the shoot growth of four potato cultivars differing in maturity classification (Solanum tuberosum L. ‘Superior,’ ‘Norchip,’ ‘Kennebec, rs ‘Russet Burbank’) were determined in controlled conditions. Plants were exposed to 0.11 ppm SO2 and/or 0.11 ppm NO2 for 24 hours a day for 7 or 14 days. There were no significant differences in leaf growth of ‘Superior’ or ‘Norchip’ plants at 7 or 14 days. Stem dry weight was significantly reduced in ‘Superior’ only after 14 days in the mixture. ‘Kennebec’ and ‘Russet Burbank’ plants had significantly less leaf area, leaf fresh weight, and leaf water content after 14 days of exposure to the mixture, but there was no significant change in dry weight. Specific leaf weight was significantly increased in the mixture treated plants of both cultivars. The two earlier maturing cultivars, ‘Superior’ and ‘Norchip,’ were less sensitive to the SO2 and NO2 combination than the two later maturing cultivars, ‘Kennebec’ and ‘Russet Burbank’.  相似文献   

2.
Irish potato vines of ‘Norland’ and ‘Kennebec’ cultivars were exposed to 387 μ/m3 ozone for 3 hr once every wk throughout their growth. Tubers of ‘Norland’ and ‘Kennebec’ were harvested at 120 and 140 days, respectively, from exposed and non-exposed plants. The experiment was conducted in 1977 and again in 1978. Ozone induced severe foliar injury to ‘Norland’ and slight injury to leaves of ‘Kennebec’ Tubers from ozone treated plants displayed a significant reduction (0.35 mg TTGA/100 g fresh weight tuber tissue) in tuber total glycoalkaloids (TTGA) when expressed on a fresh weight basis. However, since differences were not detected for TTGA on a dry-weight basis, the fresh-weight TTGA differences may only reflect variations in moisture content. In a separate experiment, both ‘Norland’ and ‘Kennebec’ were exposed to 488 μg/m3 ozone for 3 hr when the plants were 18 days old. When leaves were harvested three days later, no significant differences were detected between leaf total glycoalkaloid (LTGA) levels of treated and nontreated plants.  相似文献   

3.
Studies were conducted in Potter Co., Pennsylvania to investigate the effect of powdery scab (Spongospora subterranea) on five potato cultivars (Norchip, Rosa, Kennebec, Katahdin, and Monona) at two planting dates. Soil temperature was within the range of 15–18 C and soil moisture was within 15–19% based on dry weight throughout the season. The effect of planting date was significant at each disease assessment, except for the severity on the fourth assessment. By the end of the season, incidence of scab was 66% or more for all cultivars. Rosa, Kennebec and Katahdin had a greater scab incidence over both planting dates and a greater severity at the first planting date than Monona and Norchip.  相似文献   

4.
New cultivars ‘Alpine Russet’, ‘Dakota Trailblazer’ and ‘Ivory Crisp’ have lower tuber reducing sugars and acrylamide-forming potential. Adoption of new cultivars by growers requires information about their responses to agronomic factors such as nitrogen (N) fertilizer. The objective of this study was to determine the effect of N rate on yield and quality of new cultivars relative to conventional cultivars ‘Russet Burbank’ and ‘Snowden’. The experiment was conducted over two years as a randomized complete block design replicated four times with five N rates and five cultivars. The new cultivars had comparable or higher marketable yields, and a higher percentage of large tubers (greater than170 g) than the standard cultivars. Total and marketable yields responded quadratically to N and optimized at 231 kg ha?1 in 2011 and 319 kg ha?1 in 2012 for all cultivars. ‘Dakota Trailblazer’ had high hollow heart incidence (greater than 10% at N rates above 125 kg ha?1), and excessively high specific gravity, making it undesirable for processing but with potential to be a parent in a breeding program. ‘Alpine Russet’ and ‘Ivory Crisp’ had specific gravity suitable for commercial processing, and low hollow heart incidence at all N rates. Critical petiole nitrate-N concentrations 50 and 70 days after planting for all cultivars were greater in 2012 than in 2011, suggesting that interpretation of critical values can be affected by growing conditions.  相似文献   

5.
Feeding by psyllid nymphs causes “Psyllid yellows,” a characteristic yellowing of shoots which results in a dramatic loss of tuber yield. If psyllid infestation is not controlled, the onset of shoot yellowing and growth reductions can occur within two weeks. When insecticides are applied after yellowing, recovery of plants often is not complete. In this study comparisons were made of the physiology and growth of tops and tubers of recovered and permanently injured potatoes of the cultivars ‘Denali,’ ‘Kennebec,’ and ‘Norgold Russet.’ Permanently injured plants senesced rapidly, developed less shoot growth, aerial tubers and shortened and thickened internodes. They had lower tuber yields than plants that recovered. Permanently injured ‘Denali’ developed shoots on old flowering stems. In permanently injured plants of all cultivars, the tubers were small and badly misshapen but numbers increased. In recovered ‘Kennebec’ plants tubers were also misshapen, but were of average size. Tubers of recovered ‘Denali’ and ‘Norgold Russet’ were of acceptable shape. In samplings made during tuber growth, dry weight percentages of total soluble sugars, sucrose and glucose of tubers from permanently injured plants were found to be the same as those of recovered plants. In all cultivars, starch percentages of tubers from permanently injured plants were higher than that of the recovered, but the pattern of carbohydrate content changes was similar for permanently injured and recovered cultivars.  相似文献   

6.
Tuber tissues of 123 commercial cultivars were tested for their ability to synthesize solamarine glycoalkaloids. Eleven cultivars including ‘Kennebec’ and ‘White Rose’ synthesized major concentrations of solamarines, ranging between 42 and 85% of total glycoalkaloid, when tuber slices were exposed to light during wound-healing. Tuber tissues of the other 112 cultivars did not synthesize solamarines, or they synthesized only trace concentrations of these unusual glycoalkaloids. Nine of the 11 solamarine-synthesizing cultivars have a common ancestor, USDA 96-56. This parental clone synthesizes major solamarine concentrations and it also carries the R1 gene for late blight resistance that it inherited fromSolatium demissum. Results of solamarine analyses of foliage from 47 USDA 96-56 selfed progeny suggest that this parental clone is the source of a major gene(s) for solamarines present in 9 of the commercial cultivars. However, there appeared to be an alternative source of a gene(s) for solamarines because ‘White Rose’, with onlyS. tuberosum ancestors, also synthesized major solamarine concentrations. There was no association between the R1 gene for late blight resistance and the ability to synthesize solamarines in 31 USDA 96-56 selfed progeny that were analyzed for both characters.  相似文献   

7.
Potato cultivars Norland, Kennebec, and Russet Burbank were inoculated with a Minnesota isolate of potato virus S (PVS) in the field. The incidence of secondary infection, measured by enzyme-linked immunosorbent assay (ELISA), indicated that significantly more PVS infection occurred in Russet Burbank than Norland or Kennebec, and that Norland had significantly more infection than Kennebec (P≤ 0.01). Mature plant resistance was not observed. Rapid reinfection of PVS-free seedlots resulted from inoculum point-sources when routine cultivation practices were followed. Reinfection rates were significantly greater for seedlots grown at Grand Forks, ND, when compared with seedlots grown at Becker, MN, during both years of the study (P≤ 0.01). After two years in the field, reinfection rates for Norland (71.8%) and Russet Burbank (73.0%) did not differ significantly, but were significantly greater than the reinfection rate for Kennebec (29.5%) (P≤ 0.01). In greenhouse-grown plants, PVS moved out of rub-inoculated leaves within 24 hr, however, 13 and 20 days were required before PVS was detected with ELISA in foliage above and below the inoculated leaf, respectively. The frequency of PVS detection was significantly greater in foliage above the inoculated leaf compared to foliage below the inoculated leaf (P≤ 0.05). Translocation of PVS from inoculated leaves to daughter tubers occurred within 13 days for Russet Burbank and Norland and within 20 days for Kennebec.  相似文献   

8.
Wound-healing tuber tissues from two potato cultivars, one resistant (cv. Reddale) and one susceptible (cv. Kennebec) to Verticillium wilt caused by the fungusVerticillium dahliae were treated with elicitor preparations of either an autoclaved mycelial extract of the fungus or with the fungal component arachidonic acid (AA). Wound-healing tissues were analyzed for hypersensitive cell browning (HCB) and alterations in lipoxygenase (LOX), polyphenoloxidase (PPO), and peroxidase (PER) activities, because all three enzymes are thought to be involved in the hypersensitive response and plant defense. Healing Reddale tissues that were treated with the elicitors exhibited a much more rapid and intense HCB than did the healing Kennebec tissues. By 96 h, Reddale tissues treated with either elicitor preparation appeared dark brown and necrotic. Treated Kennebec tissues appeared only slightly darker than the controls after 96 h. LOX, PPO and PER activities in treated Reddale tissues were significantly less than that found in the control after 48 h, and by 96 h PPO and PER activities were nearly zero. In contrast, LOX activity in AA-treated Kennebec disks was higher than in the control at 96 h, while the activities of PPO and PER had decreased to about 60% of the control at the same time period. Our results show that HCB is strongly correlated withV. dahliae and AA elicitor treatments in the resistant vs. the susceptible cultivar, while the overall role of the three enzymes in cell browning and death remain unclear.  相似文献   

9.
Huanglongbing (HLB) is the most devastating disease of citrus worldwide. It is caused by bacteria of the genus ‘Candidatus Liberibacter’ and transmitted by two psyllid species, the Asian citrus psyllid (ACP) Diaphorina citri, and the African citrus psyllid Trioza erytreae. Considerable research has been conducted toward developing and implementing HLB and ACP management strategies. With respect to ACP control, of interest is that reports indicate guava, Psidium guajava, can be repellent to ACP. We conducted research to further evaluate repellency of guava to ACP. In one set of experiments, guava oil from five Brazilian guava cultivars (‘J3’, ‘Pedro Sato’, ‘Século XXI’, ‘Thailand’ and ‘Paluma’) was extracted from leaves (immature and mature) by hydro-distillation in a Clevenger-type apparatus and evaluated for psyllid repellency. In a second set of experiments, repellency of guava leaves to ACP was investigated using leaves (immature and mature) from two guava cultivars in Florida, ‘Pink’ and ‘Thai White’. In each set of experiments, repellency was evaluated by releasing ACP adults into a cage with two large vials, one containing a young flush shoot (= immature leaves) of Murraya exotica (a favored host plant of the psyllid, the flush of which is highly attractive to ACP) and one with M. exotica flush and the test material of interest (guava oil, immature guava leaf or mature guava leaf). The adults were free to move throughout the cage and into the vials, and the number of psyllids in each vial was counted after 24 h. The results showed that all guava materials tested had at least some repellency to ACP. Mature leaves tended to have a greater repellent effect than immature leaves. Each of the five oils exhibited repellency. A report in the literature suggested that sulfur compounds associated with guava may be responsible for ACP repellency. Interestingly, the five guava oil extracts we studied were repellent to ACP but none contained any sulfur compounds. Identification of the constituents responsible for repellency could lead to new ACP management tactics.  相似文献   

10.
An action threshold of 3-10 green peach aphid,Myzus persicae (Sulzer), apterae per 100 lower leaves is recommended for use in Minnesota to prevent further spread of potato leafroll virus (PLRV) in potato,Solarium tuberosum L. This threshold was first developed and validated using the PLRV susceptible cultivar Russet Burbank. Here we report experiments to determine if higher aphid densities could be tolerated in PLRV resistant cultivars,i.e., Kennebec (moderately resistant) or Cascade (highly resistant), without an increase in PLRV infection. Insecticidal sprays were applied to plots when predetermined target aphid densities, based on number of apterae per 100 leaves, were reached: 3, 10, 30, and 100 (Russet Burbank); 10, 30, 100, and 300 (Kennebec); and 30, 100, 300, and 1000 (Cascade). The response variable was the average percentage of PLRV infected plants. Overall mean cumulative aphid-days and percent PLRV infection were 617 and 23.5% for Russet Burbank, 1,296 and 10.2% for Kennebec, and 4,816 and 9.5% for Cascade. For each cultivar, the highest target aphid density tolerated without an increase in PLRV spread was determined by comparing PLRV infection in plots sprayed on predetermined thresholds to PLRV infection in plots where aphids were rigorously controlled. This maximum density was 10 apterae per 100 leaves for Russet Burbank and 300 apterae per 100 leaves for Cascade. Results using Kennebec were ambiguous, but Kennebec was always more resistant to PLRV than Russet Burbank. Excised leaflet tests showed that the cultivars did not differ in resistance to green peach aphid. It appears that action thresholds based on green peach aphid apterae can be different depending upon the inherent PLRV-resistance of the cultivar.  相似文献   

11.
Experiments were conducted in 1969 and 1970 to determine the influence of chemical treatments of seed pieces and soil on the development ofVerticillium wilt as measured by tuber yield increases and reduction in severity of tuber defects. The influence of storage onVerticillium-induced tuber defects was evaluated. Seed treatment chemicals tested included zinc ion maneb, maneb, maneb-chloroneb, Polyram, benomyl, and thiabendazole. Soil treatment chemicals included O-Diethyl (O-methyl-sulfinyl) phenyl phosphoro-thioate, disulfoton, phorate, carbofuran, aldicarb, ethyl 4 (methyl- thio)-m-tolyl isopropyl phosphor amidate, benomyl, and thiabendazole. Inoculated seed pieces and artificially infested plot areas were used the first year while the second year natural inoculum from a previous crop was the source of infection. Kennebec and Katahdin cultivars were tested in 1969 and Kennebec alone in 1970. Verticillium-induced yield reductions and tuber defects were more severe in all respects with Kennebec than with Katahdin. With Katahdin the only significant evidence of infection was stem end discoloration. Seed treatments, with the exception of benomyl or thiabendazole, which were erratically phytotoxic, resulted in consistent yield increases and reduction in pink eye severity. In 1969 seed treatment reduced stem end browning in Kennebec. Soil treatment with disulfoton, carbofuran, and aldicarb, both alone and in combination with seed treatments resulted in consistent yield increases with Kennebec. The seed piece and soil treatment combinations tested in 1970 appeared to have an additive effect on yield increase from combination treatments equivalent to the gain from soil treatment alone plus seed treatment alone. The nematicide soil treatment materials did not influence yield. Tuber stem-end browning and pink eye defects in Kennebec did not increase in severity over a five month storage period.  相似文献   

12.
The effect ofFusarium solani (Fsc),F. sambucinum (Fs),Erwinia carotovora subsp.atroseptica (Eca), andE. carotovora subsp.carotovora (Ecc) inoculated singly and in combination (FscFs, FscEca, FscEcc, FsEca, FsEcc, and EcaEcc) on wound-healed potato seed pieces of the cultivar Kennebec was studied. Potato seed pieces wound-healed for 5 days at 13 C and approximately 100% relative humidity, inoculated with Fsc, Fs, Eca, Ecc and their combinations, and incubated for 10 days at 9 C were protected from Eca, Ecc, and EcaEcc. When wound-healed potato seed pieces were inoculated with Fsc, Fs, Eca, Ecc, and their combinations and planted in soil maintained at 7, 10, 15, 20 and 25 C, wound-healing protected seed pieces from all pathogens and their combinations in seed pieces held for 10 days at 10 and 15 C. When seed pieces of cultivars Atlantic, Kennebec, Norchip, Russet Burbank and Superior were inoculated with Fsc, Fs, Eca, Ecc, and their combinations, different levels of protection were observed: Russet Burbank had the highest level of protection, Atlantic and Kennebec were intermediate, and Norchip and Superior were slightly protected. Dusting mancozeb on wound-healed seed pieces before inoculation with Fsc, Fs, Eca, Ecc, and their combinations increased protection against all pathogens and their combinations by 39% or more compared to the nonchemical control.  相似文献   

13.
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14.
Intercross and backcross populations derived from aSolanum tuberosum L. (2n = 2x = 48) ×Solanum chacoense Bitt. (2n = 2x = 48) cross by selecting for resistance to potato leafhopper (PLH) (Empoasca fabae Harris), were tested in the field. In F2 and F4 populations, the levels of nymphal infestation and leaf necrosis from PLH feeding were considerably lower and tuber yields were much lower compared with those measured on the susceptible cultivar Kennebec. No differences were found between the two populations. Backcrosses of the F2 and F4 populations toS. tuberosum decreased resistance to PLH. Resistance to infestation was still greater than that of Kennebec; severity of leaf necrosis equaled that of Kennebec. Tuber yields increased, but were less than Kennebec’s yield. Foliage types shifted closer to those ofS. tuberosum. Three generations of selection and intercrossing within the backcross populations did not change the level of resistance to PLH but did tend to lower tuber yields. Foliage types remained primarilyS. tuberosum in appearance although distinctive types segregated with increased frequency. A second backcross toS. tuberosum did not change the level of resistance to PLH or the level of tuber yield relative to those of the first backcross or Kennebec.  相似文献   

15.
The cultivars Atlantic, Kennebec and Katahdin were compared as to their storability and cooking qualities for the storage seasons 1974–75 and 1975–76. The studies show Atlantic was equal to Katahdin and Kennebec with regard to storability, except that at storage temperatures above 40°F (4.5°C) for 6 months, sprouting was excessive. Storage losses due to Fusarium tuber rots from natural infection were higher in Atlantic than either Katahdin or Kennebec. The processing quality for chips and French fries of Atlantic was equal or slightly better when compared to the other varieties tested.  相似文献   

16.
为研究不同茶树品种的光合特性差异,在自然条件下测定云南省9个主要栽培茶树品种叶片的光合与生理参数,并绘制相应光响应曲线。通过统计分析、主成分分析、聚类判别分析和相关性分析方法,对不同茶树品种的光合特征参数进行综合评价。结果表明,叶片净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间CO2浓度(Ci)的品种间差异较大,其中,‘云山’和‘云抗10号’的Pn和Tr显著高于其他茶树品种(P<0.05),‘天生’‘宝洪’和‘十里香’的Gs显著低于其他茶树品种(P<0.05),‘昌宁大叶种’的Ci显著低于其他茶树品种(P<0.05);在低光合有效辐射(PAR)条件下,9个茶树品种的Pn差异较小,随PAR增大各品种表现出较大差异;Gs和Tr随PAR增大呈现2种变化趋势,‘香归银毫’表现出先上升后趋于平稳的变化趋势...  相似文献   

17.
Prolonged or highly variable dormancy can be a significant impediment to the efficient use of potato (Solanum tuberosum L.) microtubers by the seed industry. In the present study, reductions in microtuber dormancy duration were obtained in cultivars commonly used by the processing industry (Kennebec, Russet Burbank and Shepody). This was achieved by modifying microtuber induction media and applying various dormancy-release treatments after harvest, with or without prior storage. An 8 h photoperiod, instead of continuous darkness during microtuber induction and development, increased microtuber yield while reducing dormancy duration. Dormancy duration was also shortened by increased sucrose concentration during microtuber induction under an 8 h photoperiod. As sucrose was increased from 4 to 16% under an 8 h photoperiod, mean dormancy duration decreased by 86 d for Shepody, 65 d for Kennebec and 46 d for Russet Burbank. During theex vitro storage period, 24 h treatment with bromoethane vapor (from 0.22 ml liquid BE per L volume) or bromoethane vapor followed by a 3 d treatment of 60% CO2/ 20% O2/ 20% N2 resulted in a rapid dormancy release of freshly harvested microtubers. These dormancy-releasing treatments significantly increased minituber yields under greenhouse conditions for all cultivars when compared to untreated controls. Increased minituber yields were also observed when dormancy release treatments were applied to microtubers after storage at 6 C for 8 weeks. The results demonstrate that microtuber dormancy duration can be manipulated during growthin vitro orex vitro. However, optimization may require cultivarspecific protocols  相似文献   

18.
Forty-day-old plants of ten cultivars of potato,Solanum tuberosum L. (Alpha, Atlantic, Bintje, Caribe, Kennebec, Red Pontiac, Russet Burbank, Sebago, Shepody and Superior), were placed into a controlled environment chamber held continuously at 35 C and their growth (Plastochron Index) and several chlorophyll fluorescence parameters (O, P, T, Fv and Fr) were measured after 1, 14, 21 and 28 days’ exposure. The cultivars were grouped according to heat tolerance based upon survival of three of four plants. The least heat tolerant group, surviving 14 days, included Atlantic, Bintje and Superior. The medium heat tolerant group, surviving 21 days’ exposure, included Kennebec, Red Pontiac and Sebago. The best heat tolerant group, surviving 28 days’ exposure, included Alpha, Caribe, Russet Burbank and Shepody. In addition, chlorophyll fluorescence parameters of six plants of each cultivar were also measured after 1 h at 5, 15, 25 and 35 C exposure in a second experiment. In all cases plants in the group with the least tolerance displayed less fluorescence than the medium or high heat tolerance plants, suggesting that plants with the least tolerance to high temperature exposure had less energy transfer through PSII (Photosystem II). These plants also had a rise in T at temperatures aboveca. 15 C. A decrease in Fv during growth at 35 C was a good indicator of foliar heat damage. Chlorophyll fluorescence of plant tissue in all three groups increased after short exposure of 1 h to temperatures below 15 C and also after continuous exposure to 35 C. At both ranges of temperature, damage was probably occurring to the thylakoid membranes which inhibited re-oxidation of PSII. Since the rate of response was different, chilling and high temperature apparently differ in how they alter the thylakoid membranes.  相似文献   

19.
The effect of daminozide [Butanedioic acid mono (2,2-dimethyl hydrazide)] on growth, field establishment and productivity of micropropagated Kennebec and Russet Burbank potato was studied. Addition of daminozide to the medium significantly reduced stem length ofin vitro propagated plantlets. Optimal dose was 0.6 mg active ingredient per plant. This dose did not significantly alter the number of nodes and leaf area. Three transplanting methods were examined: direct from tissue culture to the field without protection; the same but with a plastic covering for protection; and after 7 days acclimation in a greenhouse but without protection in the field. Stand establishment ranged from 83.3 to 100%. The second transplanting method had the highest percentage establishment for both cultivars. The application of daminozide improved survival for all transplants of Kennebec and the directly planted plantlets of Russet Burbank. Independent of the daminozide treatment, plants of both cultivars hardened in the greenhouse prior to transplanting produced the highest number and yield of tubers. For Russet Burbank, daminozide caused a delay in tuberization but did not affect tuber bulking and haulm growth.  相似文献   

20.
Summary Potato cultivars Chieftain and Kennebec were prewarmed at 70°C for 15 min. prior to heating at 100°C for 18 min. in a water bath. Chieftain exhibited a large increase in fracturability upon treatment while Kennebec showed a smaller increase. Pectic substances of the two cultivars were sequentially extracted in water, sodium hexametaphosphate (0.5%), hydrochloric acid (0.05M, 50°C), and sodium hydroxide (0.05M, 5°C). The largest fraction isolated from both cultivars consisted of hydroxide-soluble pectic substances, and was followed by the acid-soluble fraction. Chieftain contained significantly greater amounts of the hydroxide-soluble fraction than Kennebec. Ion exchange chromatography revealed that the extracted pectic substances from the two major fractions consisted of a charged pectin chain with attached neutral sugars. Gel filtration chromatography revealed wide molecular size distributions for the isolated pectic substances. Pectic neutral sugar content for the hydroxide-soluble fraction (50% of total pectic substances) was greater for Chieftain than for Kennebec.  相似文献   

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