Inheritance patterns of reducing sugars in potato tubers after storage at 12 C and 4 C followed by reconditioning

Progenies from crosses of ND860-2, a low reducing sugar clone, with two potato cultivars (Trent and Onaway), differing in reducing sugar content, as well as the progenies of the parents selfed, were examined for reducing sugar content. Tubers were assessed after storage at 12 C for 10 weeks (regular storage) and 4 C for 10 weeks followed by reconditioning at 20 C for two weeks (reconditioning). After regular storage, all seedling progenies had relatively high frequencies of low reducing sugar segregates (i.e., equal or less than those of ND860-2 clone). After reconditioning, a high frequency of seedlings with low reducing sugars was observed in the progeny from ND860-2/Trent (46.7%), however, they were also found in the progeny from ND860-2/Onaway (6.7%). Results of this study suggested that progenies from crosses involving ND860-2 would segregate for low reducing sugar content regardless the reducing sugar level of the other parent.     

Incidence of mechanical injury to potatoes during certain storage-related handling operations in the Red River Valley production area

Injury to potatoes during three commercial harvesting and bin-filling operations in the Red River Valley of Minnesota and North Dakota averaged 46.9%. The varieties Norchip, Kennebec, and Viking averaged 24.1, 64.5, and 73.2% respectively in these observations. The Kennebec potatoes, which had the most injury at bin filling, had the least decay at the end of the storage period. Loss of weight during storage averaged 2.04, 2.33 and 1.75 g/kg of potatoes per week, respectively for the Norchip, Kennebec and Viking tubers. During bulk scoop operations none of the factors: type of bucket, condition of pile, or operating speed significantly influenced handling damage.     

Uniformity among virus-free clones of ten potato cultivars

Heat therapy and meristem tip propagation were used to develop two or three virus-free clones of 10 cultivars from the following sources: Epicure from British Columbia and Scotland; Katahdin, Kennebec, Keswick, Red Pontiac and Sebago from British Columbia and New Brunswick; Norchip from Alberta, Quebec and Washington; Norland from Alberta, British Columbia and North Dakota; Red La Soda from British Columbia, Nebraska and North Dakota; and White Rose from British Columbia and North Dakota. Tests prior to treatment showed that all but one of the stocks were infected with potato virus X and/or potato virus S but in only five of the ten cultivars were all clones infected with the same virus or viruses. Field trials with the virus-free clones, which extended over four years, showed that one of the Norchip clones produced fewer tubers per plant than two other clones in three years of the four years, but no consistent differences in yield or specific gravity of tubers were found among the clones of any of the 10 cultivars.     

Dakota Pearl: An attractive, bright white-skinned, cold-chipping cultivar with tablestock potential

Dakota Pearl (ND2676-10) is a medium-maturing chipping cultivar with uniform, round, bright white-skinned tubers with shallow eyes. Dakota Pearl has the ability to produce commercially acceptable chips following long-term storage at 5.5 C without the need for reconditioning. It yields well under both dryland and irrigated trial conditions in North Dakota. North Central Regional Potato Variety Trial and Snack Food Association Trial results indicate it has wide adaptability. Yield and specific gravity under dryland conditions are similar to Norchip; Dakota Pearl has a low percentage of external defects. Average set is 12 to 14 tubers per hill. Dakota Pearl demonstrates wide consumer appeal as a tablestock cultivar due to attractive tuber appearance and bright-white skin. Sensory evaluation scores for baking, boiling, and microwaving are comparable to those of standard chip cvs Atlantic, NorValley, and Snowden. The specific gravity of Dakota Pearl is similar to cvs Norchip and NorValley, lower than for Atlantic or Snowden. Total glycoalkaloid levels are low, at 1.5 mg/100 g fresh tuber tissue. The North Dakota Agricultural Experiment Station released Dakota Pearl on 23 April 1999.     

低温对马铃薯块茎呼吸及糖代谢的影响

本试验测定了两个马铃薯品种在４ ℃和１０ ℃低温贮藏条件下块茎的呼吸强度和蔗糖、还原糖的含量。 Ｎ Ｄ８６０ ２ 品种在４ ℃和１０ ℃条件下, 还原糖含量变化差异不大, 而 Ｎｏｒｃｈｉｐ 品种在４ ℃下还原糖含量远远高于１０ ℃的处理。两个品种块茎中蔗糖含量甚微。呼吸强度与还原糖含量的变化的相关性不明显。结果表明, 两个品种在低温条件下糖代谢机理不同。     

Effects of short periods of chilling and warming on potato sugar content and chipping quality

Two days of chilling (exposure to 1 C) had no detectable effect on chip color or sugar content of potato (Solanum tuberosum L.) tubers. Four days of chilling led to increases in sugars if potatoes were stored at 10 C or 19 C for 3 to 4 days after chilling ended. Longer chilling gave increases in sugars by the end of the chilling period, and returning tubers to 10 C or 19 C magnified the response. Glucose and fructose gave similar increases from chilling treatments, except that glucose levels were consistently greater. Sucrose was increased by chilling, but the response pattern did not always resemble that of the reducing sugars. Twenty-seven days of storage at 19 C after chilling lowered levels of reducing sugars late in the storage season but not in December. Cultivars differed in response to chilling. Kennebec tubers accumulated far more reducing sugars but much less sucrose than did Norchip tubers. Storage at 19 C after chilling lowered the sucrose content of Kennebec and Monona while raising that of Norchip.     

Dakchip: A white-skinned chipping cultivar

North Dakota State University announces the name of a new potato to be called Dakchip. Dakchip is a medium maturing cultivar with chip quality quite comparable to Norchip but better than Kennebec. This new cultivar has round to oblong white skinned tubers and has an excellent plant type and growth. Dakchip is comparable to Kennebec in yield but higher than Norchip. Dakchip has moderate resistance to late blight but is susceptible to most potato viruses and some races of scab.     

Role of invertase in the accumulation of sugars in cold-stored potatoes

Freshly harvested potatoes contain low levels of total invertase and high levels of invertase inhibitor. Total invertase increases sharply when potatoes are placed in cold storage, but the inhibitor is not depleted in all varieties. The absence of basal invertase activity in Norchip tubers indicates that an excess of invertase is not required for reducing sugar formation. Analyses of 37 varieties and seedlings after 3 months cold storage revealed that the reducing sugar content is not proportional to the invertase activity. High sugar contents are associated with low inhibitor levels, but low sugars are not necessarily associated with high inhibitor levels. The results indicate that invertase participates in reducing sugar formation, but other factors are responsible for the regulation of starch-sugar conversion in potatoes during cold storage.     

马铃薯不同品系贮藏期品质分析

马铃薯秋天入窖后,测定不同品系的还原糖含量、可溶性糖含量、淀粉含量,其结果为:还原糖含量入窖后到次年3月份逐渐升高,之后又快速下降,6-21还原糖含量最低,小白花还原糖含量最高;可溶性糖含量较稳定,只是不同品系表现趋势不同,6-21可溶性糖含量最低,1-38可溶性糖含量最高;淀粉含量也较稳定,6个品系总趋势为逐渐下降;1-38淀粉含量最高;大多数马铃薯品系的还原糖与可溶性糖呈正相关,可溶性糖与淀粉、还原糖与淀粉呈负相关。     

Correlations between quality parameters of potatoes during growth and long-term storage

The relationship between chip color, dry matter, sucrose, reducing sugars, ascorbic acid, protein, and storage temperature of commercially grown and stored Russet Burbank, Norchip, and Kennebec potatoes was investigated. Multiple correlation analysis of data, collected over a period of three years, demonstrated that while dry matter, reducing sugars, sucrose, and tuber weight were significant in determining chip color of freshly harvested potatoes, reducing sugars, tuber temperature, and sucrose were important in determining chip color of stored tubers. The relative importance of each parameter varied with the age of the tubers, year in which the potatoes were grown and stored, and cultivar. The multiple correlation coefficient among chip color, dry matter, sucrose, reducing sugars, and tuber weight was 0.901 for fresh Russet Burbank, 0.839 for fresh Norchip, 0.909 for fresh Kennebec, and 0.790 for the three cultivars combined. Similarly, the multiple correlation coefficient among chip color, reducing sugars, sucrose, and tuber temperature was 0.866 for stored Russet Burbank, 0.731 for stored Norchip, 0.914 for stored Kennebec and 0.790 for the combined stored material. Regression equations varied from cultivar to cultivar and from one season to another. This indicates that the quantitative relationship between the factors assayed was not sufficiently stable to serve as a general measure of prediction.     

Plant regeneration from leaf tissues of four North Dakota genotypes of potato (Solanum tuberosum L.)

An efficient plant regeneration system was developed fromin vitro leaf tissues of four North Dakota potato genotypes. The best medium for genotype ND860-2 was Murashige and Skoog medium with 20.0 μM IAA and 11.4 μM zeatin riboside. Two to three weeks of initial dark treatments had a significant effect in reducing the time for shoot regeneration and increasing the number of regenerated shoots. Four antibiotics commonly used inAgrobacterium- mediated transformation were tested for their effects on shoot regeneration. Shoot induction was completely inhibited by kanamycin at 15 mg/L and hygromycin at 4 mg/L or higher, but not by carbenicillin (except at 1000 mg/L) and cefotaxime. Hygromycin significantly stimulated shoot induction at 1 mg/L.     

Effect of short- and long-term exposure of seed tubers to low temperatures on the growth and yield of five potato cultivars

Trials were conducted in Alberta with Norchip, Norland, and Russet Burbank and in Ontario with Kennebec, Russet Burbank, Norchip, and Superior tubers to determine their response to short-term exposure to air temperatures of 0, ?1, and ?5 C and to long-term exposure to ?1, 0, 1,2, and 3 C. Exposure of seed tubers to ?1 C from 6 hours to 5 days did not affect growth characteristics or tuber yield of any of the five cultivars studied. Long-term (October–May) exposure to ?1 C in one study severely reduced emergence and tuber yield of Norchip (P<0.05). While the marketable yield of Russet Burbank was also reduced (P<0.05) by this treatment, Norland was not affected. Tubers of all cultivars exposed to air temperatures of ?3 or ?5 C for longer than 24 hours were severely injured and were not planted in the field trials at either location. In Alberta exposure of seed tubers of Norchip, Norland, and Russet Burbank to ?5 C for 6 and 12 hours caused a reduction (not significant) in yield. In Ontario, long-term storage at 1, 2, and 3 C and in combination with short-term (2 weeks) exposure to 0 or 10 C had no effect on growth or marketable yield of Norchip, Russet Burbank, Superior, and Kennebec seed tubers.     

Length of dormancy and sprouting characteristics of ten potato cultivars

The length of dormancy and sprouting characteristics of ten cultivars (Bison, Kennebec, Norchip, Norgold Russet, Norland, Red Pontiac, Russet Burbank, Viking, Dakchip, and ND8891-3), were compared. Russet Burbank had the longest dormancy period and the slowest rate of sprouting after dormancy ended. Viking and Norgold Russet had the most sprouts and Kennebec the fewest. Dakchip had the shortest dormancy period, the greatest weight of sprouts and the greatest weight loss. Dormancy was shortest in the warmest (20°C) storage. Storage at 2°C for six to nine weeks increased sprouting after dormancy ended compared with continuous 10 or 20°C storage.     

The effect of maleic hydrazide (potassium salt) on potato yield,sugar content and chip color of Kennebec and Norchip cultivars

A new formulation of maleic hydrazide (MH), a potassium salt formulation, was field tested for 3 years in Ontario to evaluate effects on yield performance, and on the sprouting and processing quality of cvs. Norchip and Kennebec potatoes. Foliar applied MH had no apparent effect on yield of potatoes, was effective in suppressing sprout growth, and had no effect on the sugar content (i.e., fructose, glucose and sucrose) of potatoes newly harvested and after 6 months storage. Although chip color varied from yearto-year, no consistent difference was found between the color of chips made from potatoes from untreated and MH-treated plants.     

Modoc: A potato variety with bright red skin and early maturity for fresh market

Modoc is an early maturing, red-skinned, whitefleshed potato cultivar for fresh market use. The Agricultural Experiment Stations of Oregon, North Dakota, California, Idaho, and Washington jointly released Modoc in 2003. Modoc was derived from a 1989 cross of ND1196-2R and ND2225-1R performed at North Dakota State University. Modoc retains bright skin color in storage and is suited for marketing directly from the field or storage. It produces slightly lower total yield than Red LaSoda or Dark Red Norland, but higher marketable yield and more desirable tuber size and shape. Modoc tubers seldom exhibit growth cracks, secondary growth, hollow heart or other external or internal defects. Dry matter content of Modoc tubers is similar to Dark Red Norland and Red LaSoda (18.9% compared to 18.8% and 17.7%, respectively). Culinary quality of Modoc was rated equal to Dark Red Norland and Red LaSoda for boiling and microwaving preparation methods. Modoc tubers are similar to standard varieties in sugar, vitamin C, and glycoalkaloid (4.5 mg/100 g) concentration. Modoc foliage clearly expresses PVY symptoms and has not demonstrated high susceptibility to viral or fungal diseases during a decade of seed production and evaluation.     

Yield and relationships among tuber size,sucrose and chip color in six potato cultivars on various harvest dates

Cultivars were harvested biweekly for yield, weekly for sucrose determinations, and stored for chipping. At the last harvest Crystal was highest in total and marketable yield. Specific gravity was higher in Lemhi, Russet Burbank, and Norchip than in Kennebec, Crystal and Dakchip. Storage tests showed Norchip had superior chipping color to other cultivars. Dakchip had better color after short rather than after long-term storage, while the opposite was true for Kennebec and Russet Burbank. Lemhi and Crystal were marginal in color throughout storage. Sucrose (mg sucrose/g fresh tuber) expressed as a sucrose rating (SR) ranged from 1.2 to 11.9 among the various cultivars and harvest dates. Correlation between SR’s and tuber size within cultivars ranged from ?.91 to ?.97. Variability in sucrose content of immature tubers explained 70% of the variability in chip color among cultivars after storage from four to six months. Sucrose levels may be used to predict relative chipping quality of various cultivars after moderate to long-term storage if measured during early tuber development when differences in sucrose concentration are greatest among cultivars.     

Predictive Markers for Cold-Induced Sweetening Resistance in Cold Stored Potatoes (<Emphasis Type="Italic">Solanum tuberosum</Emphasis> L.)

An approach has been developed to screen a large number of potato clones for cold induced sweetening (CIS) resistance in breeding programs. Two key enzymes responsible for reducing sugar accumulation during cold storage were identified. Clones with the A-II isozymes of UDP-glucose pyrophosphorylase coupled with low activity of vacuolar acid invertase enzyme had increased resistance to CIS by forming less suc, which is subsequently hydrolyzed to the undesirable reducing sugars, glc and fru. Six named cultivars and 192 genetically diverse clones from various breeding programs in USA were analyzed over two years for the two key enzymes and sugar concentration in cold stored tubers. The predictability for CIS resistance during cold storage was 94% both years. Clones classified as class A accumulated low concentration of reducing sugar glc during cold storage. It is suggested that these two predictor enzymes can be used for screening parents and selections in potato breeding program.     

Changes in sucrose synthetase and sucrose phosphate synthetase activities during storage of potatoes

Sucrose synthetase in potatoes decreased sharply after harvest and remained low during warm storage. The activity increased slowly when the tubers were placed in cold storage and continued to increase after 30 weeks. Sucrose phosphate synthetase also decreased in warm-stored Norchip tubers, but it increased in Kennebec tubers. It increased quite rapidly in both varieties during the first few weeks of cold storage and then essentially leveled off. Both enzymes decreased during reconditioning of cold-stored tubers, but they tended to increase in Kennebec potatoes after prolonged reconditioning. Sucrose phosphate synthetase was much higher than sucrose synthetase in all stored tubers.     

马铃薯新型栽培种后代低还原糖材料的筛选与评价

以新型栽培种6个杂交组合后代的156份无性系为供试材料,利用尿糖试纸法进行低还原糖材料的初筛选后,再对低还原糖材料进行低温贮藏和回暖后还原糖、干物质含量的精确测定。试验结果表明:利用尿糖试纸法筛选出19份显色为1级的材料,采用3,5-二硝基水杨酸比色法精确测定,还原糖含量小于0.4%的有16份,证明应用此法进行马铃薯块茎还原糖含量的初筛选是有效的。低温贮藏和回暖试验结果显示,无性系1、2、4和7为耐低温糖化类型,无性系3、5、6、8、9、12、13和15属于回暖反应明显的类型,无性系10、11、14和16属于低温糖化明显的类型。     

The processing potential of tubers of the cultivated potato,Solanum tuberosum L., after storage at low temperatures. 2. Sugar concentration

Summary Several clones from a potato breeding programme at the Scottish Crop Research Institute (SCRI) produced acceptable (pale) coloured fry products after five months' storage at 4°C. Chemical analysis of tuber samples taken at five-week intervals during storage at 4°C and 10°C gave a substantial variation in glucose, fructose and sucrose concentrations among the 22 clones examined. Several unnamed SCRI clones showed little accumulation of reducing sugars when stored at 4°C. In marked contrast, the cultivars Record and Pentland Dell, currently the most widely used cultivars for fry processing in the UK, accumulated far greater levels of sugar during low temperature storage. Glucose concentration proved more important than fructose concentration in determining fry colour. Clones with the lowest concentrations of glucose after storage at 4°C also showed lowest concentrations when stored at 10°C. These results are in agreement with previous reports on the predictive value of glucose levels at harvest, but this is the first identification of such low temperature, low sweetening variants in agronomically adapted clones of the cultivated tetraploid potato.