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1.
M. K. Van Ittersum 《Potato Research》1992,35(3):261-269
Summary The variation in duration of dormancy within a seed tuber lot was studied over three years by harvesting individual plants
of cvs Diamant and Désirée from field plots and by storing the tubers at 18°C. The variation in dormancy within a tuber lot
was large (especially for cv. Diamant) and was mainly caused by variation within plants.
For cv. Diamant there was a close negative relation between dormancy and the cube root of tuber weight, whereas for cv. Désirée
a relation with tuber weight was almost absent.
The duration of dormancy of a seed lot comprising tubers with a narrow range in weight can be well described by two parameters.
It is proposed to maintain the moment of 80% sprouting as the criterion for the end of dormancy of a tuber lot and to characterize
the spread in dormancy duration by the time lapse between 10% and 90% sprouting. 相似文献
2.
J. Weber 《Potato Research》1990,33(3):335-340
Summary The intercellular volume within tuber tissue increases with tuber maturation. At the same time, both tuber injury after mechanical
load and lentical perforation after water uptake by tubers in wet peat decreases. The degree of tuber injury is correlated
with intercellular space (r=−0.667,n=16) and with water saturation of tissue (r=0.697,n=16). The tubers lose water during storage. In wet soil wilted tubers take up significantly higher amounts of water than turgid
tubers, and lenticel perforation is much more frequent. Tuber maturation in autumn and low water loss during storage enhance
the cushioning effect of the intercellular gas volume of tuber tissue against outside mechanical load and internal tension
after water uptake. 相似文献
3.
Summary Effects of three rates of fertilizer nitrogen, viz. 80, 160 and 240 kg N/ha, on tuber yield and dry-matter percentage in potato
cv. Record were compared in two experiments. Crop nitrogen uptake increased with application rate but total uptake differed
between experiments. Tuber yield was highest following application of 160 or 240 kg N/ha but differences between these two
rates were not significant. Tuber dry-matter percentage was reduced in one experiment with increasing nitrogen rate, but in
the second experiment final dry- matter percentage was highest following application of 240 kg N/ha. In all treatments, positive
linear relationships were found between dry matter percentage and mean fresh weight of tubers >30 mm, but within experiments,
the regression coefficients were generally reduced by increased crop nitrogen uptake. 相似文献
4.
Summary The effect of environmental conditions on seed tuber production from true potato seed (TPS) in nurseries was evaluated in
different growing periods during two seasons in Egypt. In the autumn season, high soil and air temperatures reduced emergence
and initial foliage development of early-sown seedlings, and decreased tuber yields. In late-sown seedlings low night temperatures
and short daylengths caused early tuberization, poor foliage development and low tuber yields. In the spring season, low temperatures
and short daylengths resulted in a slow initial foliage development and early haulm-tuber competition for assimilates in early-sown
seedlings. However, tuber yields were higher than for late-sown seedlings, presumably because net assimilation and assimilate
partitioning to the tubers were impaired by above optimum air and soil temperatures in May and June. Slow development of true
seed-sown plants caused a high sensitivity towards adverse environmental conditions and would limit yielding ability in Egypt. 相似文献
5.
Summary Seven tuber attributes were measured for a number of cultivars and breeding lines: two shape indices for the length and flatness
of the potato, one index for the narrowness of the pith, three volume parameters for the relative proportion of cortical,
perimedullaryand pith zones of the potato, and specific gravity. The three index traits, specific gravity and volume of the
pith zone showed highly significant genotype x year interactions. Significant genotypic and seasonal effects were usually
detected for the three volume traits and specific gravity. The percentage volume of the cortical and perimedullary zones showed
no genotype x year interactions. Correlations between the traits were estimated, and a factor analysis was performed based
on the correlation matrix. One factor appeared to control the negative allometric relationship between the percentage volumes
of the cortical and perimedullary zones, and another factor indicated the relationship between the length and flatness indices
of the potato.
The negative association of the percentage volume with the narrowness index of the pith and positive association between the
length of tuber and narrowness of the pith suggested that long potatoes having narrow pith were inclined to have a smaller
volume of pith. Factor analysis can be used to identify genotypes with desirable tuber attributes. 相似文献
6.
A device for measuring the growth of individual potato tubers non-destructively and precisely 总被引:1,自引:0,他引:1
P. C. Struik B. J. Schnieders L. H. J. Kerckhoffs G. W. J. Visscher 《Potato Research》1988,31(1):137-143
Summary A device for measuring the short-term fluctuations in volume of individual tubers is described. Its accuracy is mostly independent
of tuber growth stage, shape and malformations.
The coefficient of variation of volume of a tuber of 40 cm3 was usually well below 0.15% when the tuber was measured four times. 相似文献
7.
Members of the Kunitz-type protease inhibitor gene family of potato inhibit soluble tuber invertase in vitro 总被引:3,自引:0,他引:3
Summary A soluble proteinaceous invertase inhibitor was purified from tubers of cv. Provita. N-terminal amino acid sequencing of the
purified protein indicated that the invertase inhibitor was a member of a family of small tuber proteins known as Kunitz-type
protease inhibitors. The purified protein was completely inhibitory to soluble tuber invertase at quantities that did not
inhibit trypsin. Based on amino acid sequence information of invertase inhibitor protein, seven candidate cDNA clones were
identified in libraries of Provita and Saturna tubers. The candidate cDNA sequences differed from each other between 2% and
5%, having several non-conservative amino acid substitutions when compared with sequence related protease inhibitors. The
results suggest invertase as an alternative target of tuber “protease” inhibitors. 相似文献
8.
Summary Variation in aggressiveness to tubers among isolates ofPhytophthora infestans sampled from three potato growing regions in the Netherlands was compared. Variation in the ability to infect tubers of cv.
Bintje was found between isolates of each of the three regional populations. The most aggressive isolate of the old population
matched the average level of the new population in its ability to infect tubers. As a consequence, the commonly used reference
isolate VK 6C can no longer be considered to be representative of the present population ofP. infestans. Therefore it is recommended that testing tuber resistance for the official list of potato cultivars with this isolate should
be discontinued.
Tuber infection and subsequent spread of the fungus in the tuber tissues were not found to be correlated. The components of
tuber pathogenicity studied were not correlated to pathogenicity factors in the foliage, as measured under growth chamber
conditions. 相似文献
9.
Changes in potato starch quality during growth 总被引:2,自引:0,他引:2
Summary Potato starch quality parameters (amylose concentration, glucose-6-phosphate content and granule size) were analyzed in relation
to the harvesting date and tuber size of four cultivars. A significant increase in the glucose-6-phosphate content and granule
size of starch was observed during tuber growth, whereas the amylose concentration was constant. Granule size increased markedly,
whereas glucose-6-phosphate content showed slightly increasing values with increasing tuber size. Amylose concentration showed
no correlation with tuber size. We conclude that the changes in the granule size, glucose-6-phosphate and amylose content
of potato starch during growth are independent of each other. 相似文献
10.
Summary The tuber dry matter concentration, [DM], of crops of potato (Solanum tuberosum L.) was related using regression analysis, to time, thermal time, incident radiation accumulated from plant emergence, and
soil moisture deficit (SMD). Variation in [DM] was best accounted for by the regression model that was a function of thermal
time above a base of 0 °C accumulated from plant emergence, and SMD. When validated against an independent data set, there
was good agreement between observed and estimated [DM] with a linear relation accounting for 79.3% of the variance. 相似文献
11.
Summary The expression of antioxidant genes has been analyzed in a potato plant and during tuber dormancy. Manganese superoxide dismutase
(MnSOD), cytosolic copper and zinc superoide dismutase (Cu/ZnSOD), catalase class II, cytosolic ascorbate peroxidase (APX)
and glutathione peroxidase (GPX) are expressed at the RNA level in all the contexts analyzed. By contrast, the expression
of the iron superoxide dismutase (FeSOD) and plastidic Cu/ZnSOD seems to be limited to green tissues, as shown by northern
blots and native gels. A complex DAB-peroxidase isozyme pattern (using diaminobenzidine as substrate) has been observed in
different developmental contexts analyzed, but hardly observed in tubers. During tuber dormancy, MnSOD and cytosolic Cu/ZnSOD
activity was relatively constant in both Désirée and Bintje varieties while catalase activity decreases. Moreover, tuber dormancy
breakage did not involve significant changes in the activity of these enzymes. On the basis of these results, the possible
link between active oxygen species (AOS) metabolism and dormancy is discussed. 相似文献
12.
Summary Factors affecting the volume expansion of potato cubes during puffing in a fluidised bed were examined. It was found that
puffing temperature, initial size, pre-drying time and puffing time influenced the degree of expansion of the cube during
the puffing step. Blanching alone was found not to influence expansion, but in conjunction with the other factors it was found
that blanched samples showed greater volume expansion than unblanched samples. The optimum conditions for maximum volume expansion
were found to be; blanching for 80 s, cube size between 7.5–12.5 mm, pre-drying time of 90 min. at 90°C and a puffing time
of 270s at 130°C. 相似文献
13.
Summary Potato tuber dormancy is usually defined as lasting from tuber initiation until a sprout of 2 mm long has been formed under
storage conditions optimal for sprouting. We tried to find out whether there is a period during which buds of seed tubers
do not grow and whether different batches of seed take the same time to grow sprouts 2 mm long.
We measured changes in number of leaf primordia and length of tuber buds of cvs Diamant and Désirée over two years. After
early haulm pulling, buds did not grow for at least 60 days (‘Diamant’) or 95 days (‘Désirée’).
Buds in both cultivars and two tuber weights of ‘Diamant’ took about 20 days from the estimated onset of sprouting to grow
2 mm long. We question whether this period is always similar and thus whether the moment sprouts 2 mm long have formed is
a good criterion for the end of dormancy. 相似文献
14.
Summary The responses of two potato cultivars, Crystal and Norgold Russet, to a standard protoplast regeneration procedure were examined.
Both cultivars yielded protoplasts that survived and grew in the initial plating medium. Protoplast-derived callus tissue
also grew on the callus proliferation medium. The cultivars differed most in their ability to survive on the shoot induction
medium; changes in its growth regulator content and the quantity of agar increased shoot production of Crystal from 1% to
30% and that of Norgold Russet from 7% to 24% on modified medium under low light intensity.
Journal Series Paper 1699 of the North Dakota Agricultural Experiment Station. 相似文献
15.
Summary In 1983 and 1984 there were reports in Norway of more severe late blight infection than usual on tubers of cv. Pimpernel,
a cultivar without R-genes known to be somewhat resistant to both haulm and tuber infection. Results from routine tests confirmed
earlier experience that cv. Pimpernel shows stable resistance to tuber late blight, although the ranking of cultivars may
vary between years.
In experiments during three harvest seasons tubers of different cultivars were inoculated with isolates ofP. infestans obtained from stocks of cv. Pimpernel with severe tuber late blight and with other isolates. In these experiments the isolates
from cv. Pimpernel caused more rot on tubers of Pimpernel than did other isolates. 相似文献
16.
J. Marinus 《Potato Research》1993,36(1):63-69
Summary In three experiments seed tubers of cvs Jaerla, Bintje and Alpha, stored at 12 °C in the dark, were planted in glasshouses
on various dates at soil temperatures varying from 8 °C to 28 °C to study the phenomenon of ‘non-emergence’ with ageing seed
tubers. In general the tubers were desprouted before planting. At all plantings cv. Alpha produced normal plants. The cvs
Jaerla and Bintje, however, showed high proportions of the ‘little potato’ phenomenon when planted in cold soil, and high
proportions of decayed tubers more frequently in warm soil. When using physiologically older seed at later planting dates,
both the range of soil temperatures became wider and the proportions of seed tubers experiencing both ‘little potato’ and
decay increased. 相似文献
17.
Soile Prokkola 《Potato Research》1994,37(2):103-111
Summary Seed potatoes of cvs Record and Bintje were grown with 30, 80 or 130 kg N/ha. In the subsequent growing season the seed tubers,
which were inoculated or not with two concentrations ofErwinia carotovora subsp.atroseptica (Eca), were subjected to the same fertilization treatment. The incidence of blackleg and the level of seed tuber decay increased
from the uninoculated treatment to the higher inoculum level, but the degree varied considerably from one year to another.
Cv. Bintje was more susceptible to blackleg and yield loss caused by Eca than cv. Record. In 1990, when disease incidence
was high, the proportion of blackleg stems increased with increasing doses of nitrogen fertilizer which had been applied to
the seed crop, but was not significantly affected in 1988 and 1992. Seed tuber decay was retarded by the lowest nitrogen dose.
The yield of the subsequent crop was not affected by the nitrogen dose applied to the seed crop. 相似文献
18.
Summary The effect of water stress on yielding capacity of potatoes was studied in 3 years using four different levels of soil water
potential (0.7, 1.9, 3.4 and 7.8 atm.) in experiments in specially adapted structures that excluded uncontrolled water supply.
Seed tubers from these crops were planted in the following years to investigate effects of water stress on their subsequent
performance.
Limited soil moisture availability decreased yield and the number and size of tubers. The growing period was shortened by
1–4 weeks and dormancy period by 2–8 weeks. In the following year, seed produced under conditions of moisture stress gave
plants with 20% fewer stems. 24–33% less yield, 18–22% fewer tubers and 19–22% fewer large tubers than plants from seed produced
under abundant water supply. It is concluded that the yield potential of seed tubers can be improved by careful attention
to the availability of soil moisture during their production. 相似文献
19.
Summary Plants of early potato cultivars were sampled at successive harvests during tuber development and individual tubers were analysed
for α-solanine and α-chaconine using high-performance liquid chromatography. Mean tuber total glycoalkaloid concentration
(α-solanine plus α-chaconine) per plant decreased with time and statistically significant differences between cultivars were
observed in the patterns of decline during tuber growth. The mean tuber ratio of α-chaconine to α-solanine increased during
tuber development and was also affected by genotype. Total glycoalkaloid concentration for individual tubers of marketable
sizes (up to 50 g fresh weight) exceeded the safety limit of 20 mg per 100 g fresh weight for cultivars Home Guard and British
Queen but not for Rocket. These differences were attributable to differences in both rates and patterns of glycoalkaloid accumulation
during tuber development, although in all cultivars results were consistent with glycoalkaloid accumulation occurring in the
expanding peripheral cell layers of tubers for a considerable period after tuber initiation. 相似文献
20.
M. Van Oijen 《Potato Research》1991,34(2):123-132
Summary Potato cultivars of different maturity classes and levels of resistance toPhytophthora infestans were grown under several disease intensities in three field trials. Seasonal courses of ground cover by green foliage and
final tuber yields were determined. Light use efficiencies (LUE) were calculated from regression analyses of yield on cumulative
light interception.
Late blight reduced tuber yields by decreasing cumulative light interception without affecting LUE. No differences in LUE
between cultivars or cultivar classes were detected. Therefore, the maintenance of green leaf area is important when breeding
potatoes for optimal performance in the presence of late blight.
The results support the hypothesis that the correlation between lateness and reported resistance of potato cultivars is due
to the vigorous foliage growth of late cultivars. 相似文献