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1.
Summary Microtubers of potato cultivar Kennebec were stored for two months at 2 or 8°C and sampled at selected intervals for the determination
of glucose, fructose, sucrose and sprout weight. The aim of this experiment was to determine whether these microtubers show
the same response to storage temperature with respect to sweetening as field grown tubers. During storage at 2 °C, reducing
sugars and sucrose increased rapidly to a concentration of over 1.0 and 0.7 g/100 g fresh weight, respectively. In contrast,
in tubers kept at 8°C, only a relatively slight increase in reducing sugar concentration to 0.3 g/100 g fresh weight was observed
and sucrose concentration remained virtually the same. 相似文献
2.
Summary In eight experiments in 4 years, inoculating seed tubers withR. solani caused stem canker and in seven experiments decreased the total yield and the yield of tubers 40–70 mm. Yields of larger
tubers were usually increased. In most experiments inoculating increased the reducing sugar content of the tubers and darkened
the colour of crisps, but did not consistently affect the amounts of sucrose. Treating soil with aldicarb or oxamyl before
planting also slightly increased the total reducing sugars. 相似文献
3.
Summary A sensitive, rapid and inexpensive method has been developed for quantifying the glucose, fructose and sucrose content of
potato tubers. The method, based on selective enzyme-coupled reaction systems and the reduction of NAD to NADH, uses a microplate
reader fitted with a 340 nm filter. In one microtiter plate 96 samples can be analysed for all three sugars in less than two
hours. Several plates can be processed in parallel. 相似文献
4.
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. 相似文献
5.
Summary A greenhouse minituber production system involving low inputs of in vitro potato plantlets and propagation media is described,
in vitro plantlets of six potato cultivars were sectioned into nodal cuttings and separately planted into moist peat based
growing medium in shallow plastic trays. Cultivar differences were evident with respect to node viability, shoot regrowth
and minituber yields. Nodal viability for shoot regrowth varied between 80–100%. Maximum shoot heights were recorded with
whole in vitro plantlets (WIP) and the terminal Node-5 cluster. All cuttings produced minitubers. The terminal Node-5 cutting
and WIP produced significantly larger minitubers >3.0 g as compared to single node cuttings. Greater numbers of minitubers
were produced by the cvs Norchip, Red Pontiac and Conestoga as compared to cvs Eramosa. G8610-4PY and Shepody. Total numbers
of minitubers were 3 to 5 times higher from each in vitro plantlet that was sectioned into nodal cuttings as compared with
intact WIP: the yield ratios depended on cultivar. 相似文献
6.
Summary Pot and field experiments were carried out to test fertilizer treatments on the behaviour of potato tubers stores at 4°C and
≥90% relative humidity for 6 months. Weight losses (separated into water and dry matter) were enhanced after N and K fertilization
and decreased by increasing P supply. Glucose and fructose contents were reduced at harvest by high N-fertilizer rates compared
to no or low fertilization, but throughout storage reducing sugar accumulation was increased, sucrose reduction was decreased
and ascorbic acid was increased. K fertilization affected the chemical composition of the tubers somewhat similar to that
of nitrogen fertilization. High initial nitrate content of the tubers seemed to be increased and low nitrate values were decreased
during storage. The tubers from pot experiments showed similar changes but of greater magnitude. 相似文献
7.
Summary Potatoes were stored in non-refrigerated stores in the Marmarini area (central Greece, altitude about 50 m) and in the Polymylos
area (northern Greece, altitude about 900m). In Polymylos, the tubers (cvs Fina and Spunta) were harvested in October 1985
and stored until April 1986; the temperature in the store fluctuated between −1°C and 14°C (mostly between 3°C and 7°C). In
Marmarini, the tubers (cvs Sebago and Spunta) were harvested in December 1985 and stored until April 1986; the temperature
in the store fluctuated between 0°C and 18°C (mostly between 5°C and 10°C). Every 1–2 months tubers were analysed for dry
matter (DM), total sugars (TS) and reducing sugars (RS). In Marmarini, a significant increase of TS and RS was found in both
cultivars from December to January, followed thereafter by a significant decrease. In Polymylos, a continuous (from November
to April) increase in TS and RS was observed in cv. Fina while in cv. Spunta the sugars increased only until January, followed
thereafter until April by a significant decrease. 相似文献
8.
Summary Potato tubers (cvs Fina, Marfona and Spunta) were stored in a clamp in the region of Mount Vermion in Northern Greece (altitude
about 1400 m) from October 1985 to April 1986. No sprout inhibitor was applied. Tubers were analysed for dry matter and sugar
content at 2–4 month intervals. Cultivar and date of sampling had a no significant effect on dry matter but had a significant
effect on the total and reducing sugar contents. A significant interaction between cultivar and date of sampling was observed
for dry matter and sugars. A continuous increase of total and reducing sugars from October to April was found in tubers of
cv. Marfona. In tubers of cvs Fina and Spunta the total and reducing sugars increased, significantly only until March, and
thereafter decreased. 相似文献
9.
Summary Potatoes were left in the soil from December, when the vines died, until February (cvs Claustar and Sebago) or April (cv.
Spunta) in a location of central Greece with light, well drained soils and a mild climate. Tubers were analysed every two
months for dry matter and sugar content and usually the dry matter content did not change significantly from December to February
or April. The reducing sugars increased from December to February in tubers of all cultivars and significantly decreased in
cv. Spunta from February to April. 相似文献
10.
Summary Reducing sugar and sucrose content of potato tubers (cv. Record) grown in Tayside (northern United Kingdom (UK)) and Lincolnshire
(southern UK) were monitored during the 1984 growing season and after two months storage at 10°C. Neither latitude nor agronomic
factors were shown to affect sugar content. Significant correlations were found between the post storage reducing sugar content
and the sugar contents measured at harvest. Regression analyses indicated that in immature tubers sucrose breakdown was responsible
for reducing sugar accumulation during storage. 相似文献
11.
C. M. Menzel 《Potato Research》1985,28(2):263-266
Summary In potato (Solanum tuberosum L., cv. Sebago), benzyladenine (BA) promoted tuberization at high day/night temperatures (32°/18°C), while gibberrellic acid
(GA) and chlorethylphosphonic acid (CEPA) reduced tuberization at low day/night temperatures (22°/18°C). These results are
consistent with the hypothesis that temperature exerts its influence on tuber formation by altering the balance between endogenous
gibberellins, cytokinins and inhibitors, but not ethylene. 相似文献
12.
Britta Kowalski Felipe Jimenez Terry Lidcay Herrera Daniel Agramonte Peñalver 《Potato Research》2006,49(3):167-176
The aim of this work was to investigate whether the application of soluble chitosan in potato micropropagation can improve
microplant quality in vitro, help acclimatisation ex vitro, and increase yield and seed quality of minitubers. Potato cv.
Désirée microplants were treated in vitro with soluble chitosan added to the semisolid tissue culture medium in different
concentrations. Microplants were subsequently transferred to the greenhouse and sprayed with chitosan solutions or remained
unsprayed. Untreated microplants were also established ex vitro and sprayed with chitosan, or left unsprayed as a control.
Morphological and physiological parameters of plant growth were assessed in vitro and ex vitro. Plantlet quality was evaluated
using a ranking system. Minitubers derived from greenhouse plantlets were planted in the field in subtropical conditions,
and growth and yield parameters evaluated. The chitosan concentration most beneficial to the in vitro growth of microplants
varied between years. In treatments with the best in vitro growth, minituber number and yield in the greenhouse was also increased.
Foliar chitosan application at the acclimatisation phase stabilised the effect of in vitro treatment on yield parameters.
The seed quality of minitubers derived from chitosan treatments in vitro alone and in combination with foliar treatment at
acclimatisation was improved, giving rise to field plants with increased tuber numbers and yields. The combination of chitosan
in vitro and foliar application during the acclimatisation phase ex vitro had a greater effect on minituber seed quality than
the concentration applied in vitro. 相似文献
13.
Summary Potato plants of cvs Eersteling and Bintje were grown from stem cuttings and induced to form aerial tubers for use as seed.
Spraying the plants with gibberellic acid in concentrations of 10, 25 and 50 mg/l to induce stolon formation in the leaf axils
led to a decrease in the number of tubers formed per plant. Multiple harvesting of the largest tubers from plants treated
with gibberellic acid or not, approximately doubled the number of tubers formed but halved their individual weight compared
with only one harvest at plant senescence.
After a storage period of about 1 year, with their vigour declining, the aerial tubers were planted in the field. Aerial seed
tubers taken from multiple harvests during the previous year produced the same number of tubers as plants grown from above-ground
tubers harvested at plant senescence only, but the tuber yields declined with earlier harvesting when small (5–13 mm) aerial
tubers were used, compared to larger (14–19 mm) tubers. 相似文献
14.
Assessing progenies of potato for resistance to skin spot (Polyscytalum pustulans) in the glasshouse
Summary Crosses were made between six parents differing in susceptibility to skin spot and glasshouse-grown tubers from true seedlings
of the nine resulting progenies assessed for resistance to the disease. The assessment was evaluated by a two-year comparison
with the behaviour of field-grown tubers of the progenies and their parents. The correlations between progenies in the glasshouse
and field were r=0.911 and 0.753 and those between the mid-parental values and the progeny means were high (r>0.864), indicating
that parental differences were heritable. It is concluded that correlations were sufficient for glasshouse-grown tubers to
be used for assessing large numbers of progenies in genetical studies and for eliminating highly susceptible progenies at
an early stage in a breeding programme.
R.L. Wastie died 16.01.96. 相似文献
15.
J. Marinus 《Potato Research》1993,36(1):55-61
Summary The formation of above-ground tubers on stem cuttings of eight potato cultivars was studied over three seasons. To promote
tuber formation in the leaf axils, stems grown from single node cuttings were exposed to short day conditions. Tuber formation
underground was reduced by covering the soil with a plastic sheet and by using single node cuttings planted with the leaf
axils several centimetres above the soil surface. With all cultivars except Alpha, which produced mis-shapen tubers in all
experiments, an average of 11 (maximum 40) tubers per cutting were harvested. Significant cultivar × year interactions were
observed. 相似文献
16.
Summary Removing the leaves from single node potato cuttings in vitro allows propagules to be placed in culture vessels at increased
densities with the intent of saving resources and space. Under light intensities of 22 wattsm−2, the removal of the subtending leaf resulted in fewer nodes, shorter plantlets, smaller leaf area, and lower fresh and dry
weights of 4-week-old plantlets of cvs Atlantic, Kennebec, Russet Burbank and Shepody. Fewer nodes and reduced plantlet height
may result in inefficient multiplication protocols because fewer propagules are available and shorter internodes make dissection
more difficult. The coefficient of variation for the various growth parameters was greater when propagules lacked leaves,
indicating that the variability of the plant material for propagation was increased. A reduction of vigour and growth was
still evident when plantlets of cv. Shepody were grown for 6–8 weeks. 相似文献
17.
Summary The susceptibility of 21 potato cultivars to leak (watery wound rot) caused byPythium aphanidermatum was compared. Whole tubers were inoculated after wounding by dipping into a water suspension of 103 oospores/ml and incubated for 3 days at 25°C. The mean penetration of tissue calculated from the recording of lesion width
and depth and the qualitative assessment of rot extension were highly correlated. For 10 of 12 cultivars tested at least twice,
consistent reactions were obtained: cvs Korrigane. Superstar, Safrane and Yesmina were moderately susceptible, whereas Atlas,
Diamant, Mondial, Obélix, Spunta and Timate were susceptible to highly susceptible. Tubers originated from two locations and/or
two cropping seasons: thus, the performance of these cultivars under different production conditions reveals a satisfactory
level of agreement with the test. Moreover, ratings assigned are supported by field or store observations. 相似文献
18.
D. Levy 《Potato Research》1986,29(1):95-107
Summary The effects of high temperatures and water deficit on potatoes were investigated under field conditions. Nine cultivars and
one un-named seedling were grown in the spring and in the summer under high temperatures. In both seasons the cultivars were
grown under 3 water regimes: adequate water supply, moderate water deficit, and severe water deficit that were achieved by
a modification of the single line source sprinkler irrigation system. Severe drought reduced tuber yields in both seasons.
Moderate tolerance to a moderate water deficit in the spring season was exhibited by Draga, Désirée, and Monalisa. Late and
intermediate cultivars produced high tuber yields in the spring season, and early cultivars had relatively smaller yield losses
in the summer. The extent of tuber disorders, sprouting, rotting and malformation, varied considerably. High temperatures
enhanced sprouting, rotting and malformation and drought may enhance sprouting and malformation.
This investigation was supported by a grant from the Ministry of Foreign Affairs, Technical Assistance Department, Netherlands. 相似文献
19.
Summary The severity of late blight tuber rot in five potato cultivars (Green Mountain, Sebago, Dorita, AC Brador and Island Sunshine)
resulting from inoculation with US-1/US-8 combinations of Canadian isolates ofPhytophthora infestans was evaluated. In addition, the potential for mixed (A1∶A2) inoculations to result in oospore formation was examined. In
studies conducted in 1996 and 1997, cv. Dorita (and Island Sunshine in 1997) developed the least amount of surface or internal
necrosis relative to the other cultivars following co-inoculation with US-1 and US-8 isolates ofP. infestans. Differences also were revealed among isolate combinations used for inoculation. The combination of a US-1 isolate from Prince
Edward Island with a US-8 isolate from New Brunswick consistently produced the least amount of necrosis in tubers of the various
cultivars. There was no evidence of oospore production in any of the tubers examined.
AAFC Contribution No. 919 相似文献
20.
Summary In measuring fructose 1,6-bisphosphatase (EC 3.1.3.11; FBPase) in potato tubers, we used anti PFP antibodies to ensure that
the assay was specific for FBPase and that PPi:fructose 6-phosphate 1-phosphotransferase (EC 2.7.1.90: PFP) did not contribute
to the production of fructose 6-phosphate (Fru-6-P). The involvement of cytosolic FBPase in cold sweetening was determined
by monitoring enzyme activity during storage ofSolanum tuberosum cv. Erntestolz tubers at 2 or 8°C. In contrast to the rapid increase in sucrose and reducing sugars, the specific activity
of FBPase showed no change and PFP rose slightly during storage at 2°C. Sugar concentrations and enzyme activities remained
virtually unchanged during storage at 8°C. These data allow the interconversion of fructose 1.6-bisphosphate (Fru-1,6-P2) to Fru-6-P and vice versa by FBPase and PFP, respectively, in potato tubers, but do not support a causal relationship between
coarse metabolic control of FBPase and cold-induced sweetening. 相似文献