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1.
Summary Potatoes with an applied load of 196 N (20 kgf) were stored at 7°C for 60 days. The sugar contents (glucose, fructose and sucrose), invertase, UDP-glucose pyrophosphorylase (UGPase) and sucrose 6-phosphate synthase (SPS) of the potatoes were measured at intervals during storage. The aim of this study was to determine whether static loading affects the sugar contents and enzymes levels in potatoes during storage. Static loading increased the glucose, fructose and reducing sugar contents, as well as the invertase activity of potatoes during storage. The reducing sugar content of static loaded potatoes was correlated (P<0.01) with the invertase activity.  相似文献   

2.
低温胁迫对木薯幼苗叶片转化酶及可溶性糖含量的影响   总被引：10，自引：0，他引：10  
以华南124(SC124)、华南8号(SC8)和阿根廷7号(ARG7)3个木薯品种为材料,研究在持续低温胁迫下木薯幼苗叶片转化酶活性(SAI,NI)及可溶性糖含量的变化。结果表明:可溶性酸性转化酶(SAI)在木薯耐寒品种中(ARG7)活性较高;低温胁迫均能提高3个品种木薯中SAI酶的活性,但是在耐寒品种ARG7中表现为稳定提高。中性转化酶(NI)在木薯耐寒品种中(ARG7)活性较高,低温胁迫也能提高3个木薯品种中的NI酶活性,而NI酶活性均表现为短期提高。初步推断,SAI活性与木薯的抗寒存在一定的正相关。低温胁迫后3个木薯品种叶片蔗糖、还原糖和可溶性总糖的含量均升高,且抗寒品种ARG7叶片的还原糖、蔗糖和可溶性总糖含量极显著高于SC124和SC8。  相似文献   

3.
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.  相似文献   

4.
Summary Significant differences were found in sugar content and invertase activity of tubers of 8 Indian cultivars stored at 3–5°C. Freshly harvested tubers of all the cultivars had low amounts of sugars, which increased during storage, and little or no basal invertase activity but both basal and total invertase activities in all the cultivars increased during storage. There were significant correlations between the reducing sugar content and basal and total invertase activities. Publication no. 116, Central Potato Research Institute, Shimla.  相似文献   

5.
The processing of potatoes into chips is expanding in China. There is a need for new processing cultivars that are well-suited for the local ecological environment. Eleven potato varieties were bred from hybridization and backcrossing between the local cultivated potato varieties (Solanum tuberosum L.) and wild potato species. Lines from different wild species’ germplasms showed that the ability to accumulate reducing sugars was significantly different during low temperature storage (4 °C). A correlation analysis was conducted to determine the correlation coefficient among reducing sugars, acid invertase, free amino acids, chip colors and the content of acrylamide after storage at room and low temperatures. The lines 0706-116, 0737-6 and 0726-205 had low levels of reducing sugars, acrylamide content and acceptable chip colors for potato chip processing. The results indicated that the transfer of wild species’ processing traits into local cultivars by hybridization and continuous backcrossing is an effective potato breeding method and that the wild germplasm resources S. phureja and S. chacoense are suitable for improving the processing traits of local varieties.  相似文献   

6.
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.  相似文献   

7.
Summary The reducing sugar content and chip colour were studied in diploid potatoes bred for superior table and chipping quality. The reducing sugar content in the tubers of 119 diploid clones was estimated before and after cold storage (4–6°C) in the years 1987–1991, and reducing sugar and chip colour were determined in 1990 and 1991 for 36 clones. Thirty two clones had a significantly lower reducing sugar content after cold storage than cv. Mila. The year of evaluation, storage temperature and genotype significantly affected the reducing sugar content.  相似文献   

8.
Mechanical handling of Norchip (cv.) potatoes resulted in sucrose concentrations that exceeded 1% (fresh wt basis) 10 days after treatment. More than 65% of the maximal sugar accumulation occurred within 5 days of handling. Potatoes increased in their ability to produce sucrose as storagetime increased. Sucrose accumulation in response to handling stress was not mediated via gross physical disruption of the amyloplast membrane. Electron micrographs indicated that starch granules of both handled and control potatoes were surrounded by intact and continuous plastid (amyloplast) membranes throughout the major portion (1 to 8 months) of the storage season (8.9 C). Glucose levels did not increase at a similar rate compared to changes in sucrose concentration. Results suggest that the majority of the sucrose, which occurred during storage and/or handling stress, was not efficiently converted to reducing sugars via the enzyme invertase. Sucrose and glucose concentrations in all potatoes began to increase and chip color darkened as tubers senesced (9 to 10 months storage). Examination of electron micrographs during this storage period revealed that the bi-layers of the amyloplast membrane were separating. The mechanical handling of senescing potatoes (10 months in storage) resulted in a shift of the plastid membrane to a more disrupted state over that noted in the control. The variation in chip color induced by handling and/or storage time in Norchip potatoes was closely associated with the variation in glucose content (r = 0.953).  相似文献   

9.
A potato chipping selection F58050 with high specific gravity and low sugar content and a non-chipping cultivar Sable with low specific gravity and high sugar content were each autografted and cross-heterografted to assess source-sink relationships on specific gravity, sugar content and chip color of potatoes. Heterografting of Sable scions onto F58050 stocks reduced the specific gravity of F58050 tubers compared to autografts of F58050 (P<.05). Grafting of F58050 scions onto Sable stocks did not significantly increase the specific gravity of Sable tubers compared to autografts of Sable. Heterografting of Sable scions onto F58050 stocks resulted in significantly (P<.05) darker chip color but no significant increases in reducing sugar content of potatoes as compared to potatoes from autografts of F58050, both at harvest and after 3 months’ storage at 12 C. On the other hand, potatoes from heterografting of F58050 scion onto Sable stock showed a slight improvement in chip color and significantly (P<.05) lower reducing sugar content than potatoes from autografts of Sable.  相似文献   

10.
Studies were made on the influence of growing season and low fertility on reducing sugar accumulation in storage of the stem and bud portions of Russet Burbank and Norgold Russet potatoes separated into different specific gravity groups. The stem portion of Russet Burbank had a significantly different intercept and slope of regression line (between specific gravity and reducing sugar accumulation) than the bud portions of the same tubers indicating higher reducing sugar accumulation in the stem portion as well as differences in behavior as to amount accumulated at the different specific gravity levels. No significant difference in sugar content or behavior at the different specific gravity levels was obtained between stem and bud portions of Norgold Russet. Growing season did not cause significant differences in total sugar content or slope of the regression lines within the stem or bud portions of Russet Burbank. Low fertility level resulted in significantly higher sugar accumulation in the stem portion of Russet Burbank as compared to adequate fertility and there was also a trend toward less influence of specific gravity on sugar accumulation at the lower fertility level. Low specific gravity Russet Burbank potatoes tended to be more variable in sugar accumulation from year to year and also had wider differences in sugar accumulation between stem and bud portions than high specific gravity potatoes.  相似文献   

11.
Fifteen potato (Solanum tuberosum L.) clones with varying resistance to cold-induced sweetening were analysed for vacuolar acid invertase (AcInv, EC 3.2.1.26) and UDP-Glc pyrophosphorylase (UGPase; EC 2.7.7.9) activities related to their ability to accumulate sugars following cold storage (4 C). The UGPase isozyme profiles for each clone were also determined. Immunoblot analysis demonstrated a 55 kD protein, in seven of the 15 clones, that reacted with UGPase antisera in addition to the 53 kD UGPase subunit previously reported. The UGPase activity of these clones was significantly lower than that of the “single subunit” clones. Basal AcInv activity showed a positive correlation to the Glc:Suc ratio across the clones that was moderately significant before and after cold temperature storage. The activity of UGPase, which limits the rate of Suc formation, was of secondary importance in limiting the rate of hexogenesis when vacuolar AcInv activity was excessive. It is suggested that with the potato clones from this breeding program that AcInv (and its inhibitor) plays a dominant role in the hexogenic pathway by regulating the hexose:Suc ratio. The finding of a new protein that is reactive with UGPase antisera may prove to play an important function in the regulation of Suc formation in potatoes.  相似文献   

12.
对4个不同株高的蓖麻品种生育过程中可溶性糖、还原糖、蔗糖转化酶、可溶性蛋白、谷氨酰胺合成酶、 游离氨基酸的差异进行了比较研究。结果表明,株高快速增长时期在7月上旬至8月上旬;不同株高的蓖麻品种 其碳氮代谢指标存在差异,在生育前期叶片相对较多的可溶性糖积累和旺盛的氮代谢以及生育中后期高的蔗糖转 化酶活性、低还原糖含量有利于其株高的增长。  相似文献   

13.
Indigenous non-refrigerated methods like heaps and pits are used in India for short-term storage of potatoes (Solanum tuberosum L.) to avoid distress sale. Storing untreated potatoes generally results in high losses from sprouting, moisture loss and rotting. To reduce storage losses by inhibition of sprouting and to determine the suitability of stored potatoes for processing into crisps, a single spray application of a commercial formulation of 3-chlorophenyl carbamate (CIPC or chlorpropham) 50% a.i., (Oorja, United Phosphorus Limited, Mumbai, India) of CIPC (or chlorpropham) was tested on potatoes during storage from March to June under two traditional storage methods [heap (17–33 °C, 58–92% relative humidity (RH)) and pit (17–27 °C, 72–95% RH)] in 2 years [2005 up to 90 days of storage (DOS) and 2006 up to 105 DOS], using four cultivars and two rates of CIPC application (20 and 30 mg a.i. kg−1 tubers). The two rates of application were comparably effective in reducing weight losses, sprouting and sprout growth in stored tubers, and the effect was more pronounced in pit storage than in heap storage. By contrast to untreated tubers, CIPC-treated potatoes remained turgid under the two storage methods and fetched market prices comparable to those for cold-stored (2–4 °C) potatoes after 105 days of storage. Reducing sugar concentrations in treated potatoes decreased during storage especially in 2006 when the initial reducing sugar concentration was higher than in 2005. Crisp colour improved only in 2005 after 90 DOS, but it deteriorated in 2006 during storage up to 105 DOS. Sucrose concentration increased tremendously during storage in 2 years. Only one cultivar (Kufri Chipsona-1) with low initial reducing sugar concentration and less sucrose accumulation during storage could produce acceptable colour crisps after storage in both years. The remaining three cultivars—with high initial reducing sugar concentration—were suitable for processing after storage in heap and pit in 2005, but not in 2006. Stored potatoes were safe for human consumption as the CIPC residue concentrations were far below the permissible level of 10 mg kg−1 as prescribed by the European Union. Single spray application of CIPC (20 mg kg−1 treatment) can effectively reduce storage losses in potatoes stored in traditional non-refrigerated methods of heap and pit and extend the storage life by 90 to 105 days.  相似文献   

14.
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15.
Studies were made of pH changes of apical and basal portions of Russet Burbank and Norgold Russet potatoes during growth and in storage. Russet Burbank had a higher pH of the apical portion during the later stages of growth as compared to the basal portion. No significant differences between the two portions were found during growth with Norgold Russet. After a period of moisture stress the pH of the basal portion of Russet Burbank dropped significantly. The basal portion of both varieties at higher specific gravities had higher pH after storage than the apical portion. A highly significant negative correlation was obtained after storage between reducing sugar levels of tubers of different specific gravities and pH levels in both varieties. There were no significant differences in pH among storage temperatures of 34, 38, 42 and 45 F. However, the pH level at 48 F storage was significantly higher than at the other temperatures. The pH level of tubers from seedlings and varieties were poorly correlated with their reducing sugar contents after storage. It appears that pH can be an indicator of potential chip color only within the confined limits of a specific lot.  相似文献   

16.
以高糖(GT35)和低糖(B8)甘蔗品种苗期不同部位的叶和茎为材料,采用HPLC技术测定蔗糖、葡萄糖和果糖含量,分析2个甘蔗品种叶和茎中蔗糖代谢相关酶活性与糖分含量的相关性和差异性。结果表明:2个甘蔗品种苗期叶中蔗糖含量与SPS和SS-s酶活性呈显著正相关,茎中己糖含量与NI酶活性呈显著正相关,茎中蔗糖含量与SPS酶活性呈显著正相关,而与SS-c、SAI和CIN酶活性呈显著负相关。GT35茎中蔗糖含量显著高于B8,叶中蔗糖含量显著低于B8。GT35茎中SPS和叶中SS-s酶活性均显著高于B8,茎中SS-s和SS-c酶活性低于B8,其中只有幼茎中SS-c酶活性与B8差异不显著。说明苗期叶中高SS-s酶活性,茎中高SPS酶活性,低SS-s和SS-c酶活性,可能是调节高糖甘蔗品种苗期茎中蔗糖积累的重要因素。  相似文献   

17.
Two varieties of potatoes viz. Kufri Chandramukhi and Kufri Sindhuri were treated with Isopropyl-N(3-chlorophenyl)carbamate at two different concentrations viz. 4000 and 5000 ppm. The treated potatoes were stored for a period of four months under different storage conditions i.e. room temperature, cold and evaporative cooling chamber storage and analysed for polyphenol oxidase activity, total nitrogen content and quality of dried slices produced from these at different stages of storage. Higher nitrogen content was observed in CIPC treated potatoes as compared to control. Polyphenol oxidase activity decreased more in Kufri Chandramukhi than in Kufri Sindhuri in CIPC treated as well as in control experiments. The changes in nitrogen content and polyphenol oxidase activity were more pronounced in evaporating cooling chamber and in room storage than in the cold storage. The quality of potato slices prepared from both varieties confirmed the superiority of Kufri Chandramukhi over Kufri Sindhuri for processing purposes.  相似文献   

18.
以当地主栽的马铃薯品种大西洋、克新19号为材料,于2007年9月至2008年5月进行了山体库和恒温库贮藏比较试验,比较山体库与恒温库马铃薯不同贮藏时期温度、湿度变化与干物质、淀粉、还原糖的含量及变化。试验结果表明:山体库贮藏马铃薯期间温度、湿度的变化不大,通风情况良好,贮藏的薯块没有出现发热、失水现象。经多次分品种进行还原糖含量、淀粉含量和干物质含量三项理化指标的测定,测定结果都符合马铃薯种薯和商品薯贮藏标准。在马铃薯加工利用时,对于山体库低温长时间存贮的马铃薯根据加工利用目的,如淀粉加工、食品加工必须进行升温贮藏;山体库与恒温库在3℃条件下贮藏的马铃薯各项指标变化趋势一致,符合马铃薯种子和商品薯贮藏标准,在冷凉地区适合山体库推广应用。  相似文献   

19.
Two North Dakota breeding clones, ND860-2 and ND2221-6 accumulate very little reducing sugar in low temperature storage and will produce acceptably colored chips with little reconditioning. Progeny from diallel crosses of ND860-2, ND2221-6, Norchip and Kennebec were evaluated for reducing sugar and total sugar accumulation after 100 days of cold storage (3–4°C). Crosses of the North Dakota clones with Norchip or Kennebec produced families whose distributions were skewed towards the high parent with respect to reducing sugar values; about 2% had levels near the two low parents. Crosses between ND860-2 and ND2221-6 produced reciprocal families in which an average of 8% of the progeny had levels as low as these two parents.  相似文献   

20.
The accumulation of reducing sugars in stored potato tubers is of significant commercial importance because of its effect on processing quality. The process by which the accumulation of sugars occurs involves the interaction of many metabolic pathways and is yet to be fully described. Low temperature conditions result in an accumulation of ATP in potato tissue. Published evidence suggests that low temperature activation of the alternative pathway (cyanide resistant respiration) leads to decreased ATP levels and simultaneous increases in sucrose concentrations. This sucrose becomes the substrate for vacuolar acid invertase resulting in the accumulation of reducing sugars. Inhibition of the alternative pathway results in decreased sugar accumulation thereby minimizing the sucrose available to the acid invertase and the subsequent reducing sugar accumulation. Control of the alternative pathway on its own, or in combination with acid invertase activity, may provide insight into the phenomenon of low temperature sweetening in stored potato tubers.  相似文献   

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