Reducing sugar accumulation in progeny families of cold chipping potato clones

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.     

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 relationship of chip color with structural parameters of starch

Seven potato cultivars (Norchip, Monona, Onaway, Snowden, Atlantic, Saginaw Gold, Novachip) and the seedling ND860-2 differing in their susceptibility to low temperature sweetening were analyzed to determine if starch structural stability parameters could be used to consistently predict and/or monitor chip color (Agtron score) of potatoes during storage at 4 and 12 C. Fresh tissue gelatinization temperature (Tp) was significantly correlated (P≤0.05) with chip color for all cultivars except Onaway, Snowden and Atlantic for tubers harvested in 1993 when stored at 12 C. No correlations existed between Tp of isolated starch and chip color (P>0.05). In 1994 no correlations existed between Tp of fresh tissue, Tp of starch and chip color at either 4 or 12 C (P>0.05). Prediction of chip color based on starch stability parameters was not possible. Starch crystallinity, amylose content and starch granule size distribution could not be used to predict or monitor chip color in stored tubers.     

Storage temperature and maleic hydrazide effects on sprouting,sugars, and fry color of Shepody potatoes

The effect of low storage temperature (4 to 8 C) and maleic hydrazide (MH) treatment on sprouting, sucrose and reducing sugar (glucose and fructose) concentrations in tubers, and fry color-sugar relationships of Shepody were determined and compared to Russet Burbank. Sprouting of Shepody was delayed by 3 to 15 weeks when the temperature was lowered from 8 to 6 or 5 C, respectively. Shepody accumulated more sugars at all storage temperatures than Russet Burbank. The reducing sugars accumulated in Shepody at 5 and 6 C could be lowered to levels acceptable for processing for about 24 weeks after harvest by reconditioning at 18 C for at least two weeks. MH increased glucose in Shepody stored at 5 C compared to untreated tubers. Excessive sprouting (> 10 cm sprout length) of nonsprout inhibited Shepody occured late in storage with four weeks reconditioning. Although not statistically significant, MH tended to cause darker fry color per unit of reducing sugar in Shepody compared to tubers from untreated plants. Storage of Shepody tubers not treated with MH could be extended a few weeks by temperatures < 8 C only if there is precise control over temperature, sugars are closely monitored, and reconditioning is rapid to minimize sprouting.     

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。     

Effect of temperature on the sugar content of potato callus tissue

The effects of temperature, incubation time, callus age, and growth regulator on the reducing and nonreducing sugars of Lemhi Russet callus grown on Murashige - Skoog medium with 3% sucrose were determined. Callus grown at 25°C for approximately 4 weeks (0 time) were held at 25°C or transferred to 15°C and 5°C for 4-week periods. Callus grown at 5°C for 4 weeks was transferred back to 25°C for a 4-week period to simulate reconditioning of potatoes. The reducing sugar content decreased rapidly with time at 25°C and 15°C when either 2,4-D or picloram was used as a growth regulator. At 5°C the reducing sugar content increased or decreased slightly, depending on the original reducing sugar content of the callus. The initial reducing sugar content at 25°C and the relative effect of 5°C incubation was dependent on the age of the callus tissue. Reducing sugars in 5°C callus were rapidly lost after reconditioning at 25°C. The nonreducing sugars exhibited similar overall changes as the reducing sugars, but the nonreducing sugar concentrations were much lower. Thus, potato callus cultures are similar to whole tubers insofar as they accumulate or maintain high reducing sugars at low temperatures and lose these sugars during reconditioning.     

筛选适应于低温贮藏的马铃薯加工品种

通过对不同贮藏温度下马铃薯块茎的还原糖含量及加工品质色泽指数的测定，筛选出在简易库房贮藏条件下（４～１０℃）适于加工的品种为国引ｌ、１１、１３、２、１２号，这些品种经过３个月的低温贮存还原糖积累水平较低（＜０．５％），色泽指数小（＜２０），加工品质好．冷贮（０～２℃）和冷贮一回暖（１５～１７℃）处理结果表明，冷贮导致块茎中还原糖含量大幅度提高，色泽指数显著增大．而经过回暖处理后，还原溏含量下降，色泽指数变小，但不同的品种经不同的处理时间回暖效果不一。国引１、２号经过３０天的回暖处理，加工品质达到商业要求．     

Sugar-end in Russet Burbank potatoes

Tissue selected from the stem- and bud-end of reconditioned tubers having sugar-end disorder was compared by color after frying and chemical composition to tissue removed from the two ends of tubers without sugar-end disorder taken directly from cold storage at 45 F, and after reconditioning 3 weeks at 70 F. Chemical analyses of selected tissue suggested that the dark finish-fry color at the stem-end of sugar-end tubers following reconditioning at 70 F was due to the inability of the physiological systems within the tissue to convert reducing sugars to starch and/or to use these sugars in the respiratory process. Of the components analyzed, only a high reducing sugar content was associated with a dark finish-fry color. Neither sucrose nor free amino acid content was associated with the sugar-end disorder. Extending the reconditioning period at 70 F for sugar-end tubers did not lower the reducing sugar content or the darkening of the stem-end tissue on frying.     

Identification of potato (solarium tuberosum L.) haploid x wild species hybrids with the capacity to cold-chip

Cold sweetening, the accumulation of reducing sugars in potatoes stored at low temperatures, results in dark chips unacceptable to the consumer. Developing potato cultivars that can chip directly from cooler temperatures (i.e., 3 to 4 C) requires the identification and use of new germplasm with cold-chipping resistance. Individuals from 16 haploid x wild species hybrid families were grown at two sites and their harvested tubers stored at 3 C for 15 wk. Following storage, individuals were evaluated for cold-chipping ability by (1) direct chipping, and (2) reconditioning for 2 wk at 18 C prior to chipping. At both sites, approximately 1% of progeny had good chip color (<2.0 rating using the Snack Food Association scale). Germplasm representing haploid x wild species hybrid families was evaluated for cold-chipping ability following storage of tubers at 3 C for 15 wk, and after storage at 18 C for 2 wk. The two cold-chipping clones identified with chip color means <2.0 were AH 66-1 and H 28-6, hybrids derived fromS. raphanifolium accessions 296126 and 310998, respectively.S. raphanifolium PI 296126 was exceptional in that chip color means of its progeny were 2.5 and 2.7 at McLeod (North Dakota) and Crookston (Minnesota), respectively. All clones with chip color means <2.6 involvedS. raphanifolium PIs 296126, 310998, and 458384 in their parentage. Following reconditioning, the number of progeny in the good and medium chipping categories improved from direct chipping with 14.1% of the progeny at McLeod and 3.8% at Crookston in the good chipping category.S. raphanifolium PIs 210048 and 310998 together accounted for 100% and 50% of the clones with chip scores <2.0 at McLeod and Crookston, respectively. Clones ranking high for chip color following direct chipping generally chipped well following reconditioning.     

Zur Züchtung von Kartoffelsorten mit Kaltlagerfähigkeit unter Berücksichtigung genetischer Aspekte

Zusammenfassung Knollen von 14 Populationen wurden sowohl im S?mlings- als auch Ramschstadium nach 12-w?chiger Lagerung bei 4°C auf Kaltlagerf?higkeit (sehr geringe Zuckerakkumulationsrate) und Chipseignung untersucht. Beide Merkmale wurden an jeweils 25 Genotypen pro Population ermittelt. Die Ergebnisse des S?mlings- und Ramschstadiums sind ebenso wie die zwischen Gehalt an reduzierenden Zuckern und Chipsfarbe signifikant miteinander korreliert. Auf ihrer Basis ist deshalb sowohl eine Selektion von Populationen als auch bedingt von Einzels?mlingen m?glich. Nachkommenschaftsanalysen an Kreuzungen von Eltern mit geringer, mittlerer und hoher Zuckerakkumulationsrate w?hrend der Kaltlagerung zeigten, dass der Heritabilit?tskoeffizient des Merkmals kaltlagerf?higkeit nur mittel (0,6) ist, dass aber bei Beschr?nkung der Auswertung auf Kombinationen von Eltern mit niedriger bzw. mittlerer Zuckerakkumulationsrate die Heritabilit?t dieses Merkmals hoch (0,91) ist. Die Beschr?nkung wird aufgrund der erhaltenen logarithmischen Funktionen (S?ttigungstendenz) als erlaubt angesehen. Aussagen zum Erbgang und Erbwert der eingesetzten Genotypen werden getroffen. Nach den Ergebnissen kann bei entsprechendem Ausgangsmaterial eine erfolgreiche Züchtung k?ltestabiler Sorten betrieben werden.

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Summary A series of 14 populations in seedling and first clone stage were studied to investigate their storability at low temperatures and their suitability for crisp/chip production. Cold storage stability refers to the quality of the potato to refrain from accumulating reducing sugars completely or to a large extent when stored at 4°C. Both characteristics were determined for 25 genotypes of each population after a 12-week storage period at 4°C. The populations were selected from parents showing a significant difference in their storability at low temperatures. Based on their different rates of sugar accumulation, these parents were placed into three categories. The content of reducing sugars was colorimetrically quantified in alcoholic extracts after reaction to p-hydroxybenzoic acid hydrazide; the suitability for the production of crisps/chips was assessed in frying tests. These methods are suitable for seedlings (greenhouse) as well as to the first clones (field) to assess the populations and the breeding value of parents (Table 1). Both tests are significantly correlated:r=0.98 (parents);r=0.88 (progeny); α=0.1%. Deviations of reducing sugar content in absolute terms are caused by commonly known environmental influences. Variations caused by environmental influences can be characterized by the standard deviation of the reducing sugar content as determined for various parents. This standard deviation varied in most cases between 0.05–0.07. An analysis of the parent progeny relation showed an intermediary inheritance (Table 1) for storability at low temperatures. The coefficients for heritability (for seedlingsh ²=0.586 and for first clonal generationsh ²=0.602) derived from parent to progeny regression are relatively low (Figs 1 and 2) as might be expected according to Table 1. A closer study reveals that with crosses of parents less suited for cold storage, the mean population value shows a shift towards the partner with a low or medium rate of sugar accumulation. According to the postulated intermediary heritability, this increase in reducing sugar content after cold storage is too low, a fact which is caused by physiological conditions (turgor, solubility). The logarithmic functions obtained (y=0.357lnx+0.698 for seedlings andy=0.362lnx+0.77 for first clonal generations) show as well that a saturation level has been reached. If the evaluation is limited to crosses of partners with good or medium storability at low temperatures, the coefficients for heritability are:h ²=0.922 for seedlings andh ²=0.892 for first clonal generations. This indicates good possibilities to improve this characteristic through breeding. On the base of the data obtained it can be assumed that storability at low temperatures most probably follows polygenic inheritance.

     

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。     

Factors influencing reconditioning of Russet Burbank potatoes

Studies were made to determine factors which influence reconditioning of Russet Burbank tubers. Tubers from plants grown under low fertility were more difficult to recondition than tubers from plants adequately fertilized. Low specific gravity potatoes were also more difficult to recondition than high specific gravity potatoes even though the initial sugar content was approximately equal. The stem portion of Russet Burbank tubers lost considerably less sugars than the bud portion during the reconditioning process. It appears that factors which are responsible for high sugar development are also responsible for difficulty in sugar loss. Results also indicate greater difficulty in reconditioning early in the storage period with the loss of sugars becoming easier as the storage season progressed into spring.     

甜玉米主要数量性状配合力研究

应用Griffing方法(一)研究了六个甜玉米及到杂交后代的配合力表现．结果表明，穗行数主要受加性基因控制，穗长主要受非加性基因控制。其余大部分数量性状的加性和非加性基因效应同时存在。含糖量的反交效应明显，在育种实践中应予以重视．对于这些性状而言，一般配合力高的亲本容易产生特殊配合力高的组合，。但也不排除从一般配合力都不高的双亲获得较高特殊配合力组合的可能性。根据配合力互补原理可望从这六个亲本间选配出高产高糖组合。     

The effect of direction of hybridization (4x × 2x vs. 2x × 4x) on yield of cultivated potatoes

The types of reciprocal differences found in higher plants are generally limited to those characters which are controlled by one or two major genes. There are, however, a few examples where the progeny from reciprocal crosses differ in yield or other quantitative characters. Both have been ascribed mainly to cytoplasmic inheritance. In cultivated tetraploid potatoes (Solatium tuberosum Group Tuberosum) differences in yield of the progeny from reciprocal crosses have been found. These reciprocal differences are attributed to the mode of 2n gamete formation rather than cytoplasmic differences. Preliminary experiments involving reciprocal crosses between Tuberosum cultivars (2n=4x=48) and Phurejahaploid Tuberosum hybrids (2n=2x=24) indicated that some progenies from 4x x 2x crosses yield more than progenies from reciprocal crosses. It was hypothesized that the differences in tuber yield may be due to one or more of the following factors: (i) the effect of high fruit set on yield —i.e. almost 100% of the progenies from 2x X 4x crosses are male fertile and thus higher fruit set is expected than in the 4x X 2x progenies where only about 57% of the F₁ clones are male fertile; (ii) the advantage of being in 4x cytoplasm if the nucleus is 4x; and (iii) the difference in mode of 2n gamete formation-first division restitution (FDR) gives highly heterozygous gametes and second division restitution (SDR) results in highly homozygous gametes. Six families of reciprocal crosses between three 4x cultivars (Merrimack, Superior, and Wis 639) and three 2x Phureja-haploid clones (W5293.3, W5295.7, and W5845.1) were planted in 1970 in Rhinelander in a split-plot design with two tubers of each clone in each of two replicates. Flowers were removed from one of the paired plants in each family. Even though the fruit yields were higher in 2x X 4x progenies as expected, tuber yields were not affected by fruit formation. Therefore, factor (i) is apparently not involved in the reciprocal differences observed. Significantly higher tuber yields were obtained from 4x X 2x families only with the 2x clone W5295.7. This eliminated factor (ii), since no difference in reciprocals was obtained with the other 2x clones. Factor (iii) could thus be responsible for differences in reciprocal crosses, since cytological observations indicate only W5295.7 of the 2x clones used forms 2n pollen by FDR.     

The immediate effect of gamma irradiation upon the sugar content of potatoes previously stored at 2, 4.5, 6, 10 and 15.5°C

Summary The sugar content of samples of potatoes, cv. Majestic, was varied by storage for 4 weeks at 2, 4.5, 6, 10 and 15.5°C, before irradiation with 10 krad. With initial sucrose contents of 0.14–0.37% FW (tubers from 4.5–15.5°C) the marked temporary increase in sucrose, as reported previously, was observed, reaching a maximum after 3–7 days before falling rapidly to a level rather higher than in non-irradiated tubers. Tubers from 2°C, with 1.4% sucrose, showed an immediate drop in this after irradiation, succeeded within 3 days by a rise to values not significantly different from the controls. Irradiation caused a significant increase in reducing sugar content, for a period of up to 7 days in sweetened tubers, but for 21 days or more in unsweetened tubers. Previous storage at the different temperatures had some permanent residual effect upon the sugar content of the controls during subsequent storage for up to 90 days at 10°C.     

High temperature storage of potato (Solanum tuberosum L.) for processing — a feasibility study

Tubers of three potato cultivars were stored at room temperature (20–39°C, 30–75% RH), under an insulated storage run on passive evaporative cooling (16–30°C, 70–90% RH) and a refrigerated storage (2–4°C, 90–95% RH) for 14 weeks and studied periodically for storage losses, reducing sugar content and dry matter percent of tubers, in order to explore the possibility of storing potatoes for processing at higher temperatures. Physiological losses in tubers remained less than 10% until 12 weeks of storage under evaporatively cooled storage. Reducing sugar contents increased by only 52.4–242.1% in tubers stored in evaporatively cooled storage as compared to 90.5–484.2% increase in tubers stored in refrigerated storage until 14 weeks. Potatoes stored in evaporatively cooled store were more suitable for processing into chips and french fries due to lower physiological losses and lower reducing sugar content of tubers.     

The influence of storage and conditioning on the content of reducing sugars in potatoes grown in Norway

Summary The content of reducing sugars decreases rapidly in the last part of the growing season. It is shown that one week's storage (7 C) at this stage of the tubers' development induces a remarkable increase in the reducing sugar content. Storage experiments during the period December–March show first-order interactions, viz. variety storage temperature, and time of sampling during the storage period, storage temperature. Six weeks' conditioning of the above mentioned potato material eliminated the earlier differences in the content of reducing sugars. After only 4 weeks conditioning, however, highly significant differences between potatoes from previously differing storage temperatures were obtained. The treatment comprising previous storage at 7.3 C dusted with sprout inhibitor, gave about the same amount of reducing sugars after 4 weeks as the other treatments after 6 weeks conditioning.     

马铃薯高代系炸片色泽分析与加工品质评价

试验以241个高代系为材料,在块茎4℃贮藏40d后,对还原糖含量和炸片色泽进行了分析。结果表明,加工品种Atlantic薯片色泽指数(CCI)为4.33,在所测定的杂交后代中,04HE30-17等11个品系的CCI低于Atlantic。亲本组成分析表明,51-5、393160-4和395049.62为亲本的组合中,后代中出现油炸色泽较好品系的机率较高。     

Potato tuber sugar content during development and storage (10°C): possible predictors of storage potential and the role of sucrose in storage hexose accumulation

Summary Reducing sugar and sucrose contents of potato tubers (Solanum tuberosum L.) from six cultivars were monitored both during the growing season and after a four months storage period at 10°C. Significant correlations were found between tuber sugar contents (sucrose, reducing and total) measured at harvest and the reducing sugar content after storage. Similarly, in five of the six cultivars, the sucrose loss and the corresponding reducing sugar gain during storage were significantly correlated.     

The effect of controlled atmosphere storage at 4°C on crisp colour and on sprout growth,rotting and weight loss of potato tubers

Summary After three weeks curing at 10°C, potato tubers cv. Record were stored at 4°C under different controlled atmospheres (CA) for six months to study the effect on crisp fry colour, sprout growth and rotting. Combinations of low levels of CO₂ (0.7–1.8%) and low levels of O₂ (2.1–3.9%) gave a significantly lighter crisp colour, low sprout growth and fewer rotted tubers compared with 0.9% CO₂ and 21.0% O₂. Tubers stored in these conditions. showed a significantly higher weight loss and shrinkage after reconditioning. High CO₂: low O₂ combinations during storage completely inhibited sprout growth and caused the darkest crisp colour, but after reconditioning tubers gave the same level of sprouting and crisps as light as the other CA combinations. Furthermore these combinations, especially CO₂ at 10 or 15%, increased the onset of rotting. Also our results showed that at low concentrations of CO₂ (0.7–1.6%), and low O₂ (2–2.4%) there was an increase in tuber rotting.