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1.
Summary A reverse of the delaying effect of gibberellic acid (GA3) was observed in in vitro tuberization of potato plantlets when the medium contained 0.8×10−5 M jasmonic acid (JA). The promoting effect of JA seemed to be correlated with the initial absence of growing roots, probably
through direct activity of JA in microtuber-producing buds in the stoloniferous shoots. This is based on the fact that JA
did not inhibit root growth a posteriori. Endogenous gibberellins (GAs) synthesized by roots did not interfere with the previous
activity of JA in tuberization. The absence of a JA promoting-effect on tuberization of previously-rooted plantlets could
be related to the capacity of potato roots to synthesize endogenous GAs which might antagonize the JA effect on buds of stoloniferous
shoots. 相似文献
2.
Effect of inorganic nitrogen nutrition on cytokinin-induced potato microtuber production in vitro 总被引:1,自引:1,他引:0
Summary The effect of inorganic nitrogen nutrition on the induction and development of microtubers by cytokinin-induced tuberization
was studied in four potato genotypes belonging to different maturity groups. The objective of this study was to investigate
whether a reduction in total nitrogen level in the Murashige & Skoog medium would improve cytokinin-induced tuberization rate.
The effect of three levels of total nitrogen (15, 30 and 45 meq) on tuberization was studied at constant (20 meq K) and varying
potassium levels approximating to 5, 10 and 15 meq. Reducing the total nitrogen supply increased the number but decreased
the size of nitrogen level on the rate of assimilate partitioning (harvest index) during cytokinin-induced microtuberization. 相似文献
3.
Summary Large scale, commercial production of potato minitubers, cvs Spunta, Jaerla and Kennebec, has been carried out in VITRO HELLAS
S.A. since 1995, according to protocols based on in vitro methods. Apical meristems were cultured on MS medium supplemented
with 1 μM IBA, 20 g/l sucrose and 6 g/l agar (pH 5.8). Subculture was carried out every 15 days. Multiplication rate was 4–5
per cycle. Self-rooted microplants were transferred into screen houses (200 plants/m2) in a mixture of peat and perlite 1∶1 (v/v). Cultivation period was 15 August to 15 November each year. During the period
1995–1997, the number of minitubers produced/plant was 2.07 for cv. Spunta, 1.85 for cv. Jaerla and 2.52 for cv. Kennebec
and their average weights were 10.8 g, 10.9 g and 9.8 g, respectively. The percentage of minitubers<10 mm in diameter was
2%, 50.1% were 10–20 mm and 47.9% were>20 mm. 相似文献
4.
Summary Ancymidol-induced in vitro tuberisation under different photoperiodic regimes (dark, SD=8 h, LD=16 h) and sucrose concentrations (2, 4, 6 and 8%) in cv. Jaerla (early) and cv. Baraka (late) was studied. Tuberisation was scored after 4 (dark) or 8 (light) weeks. Ancymidol significantly increased tuberisation under LD-SD for any sucrose concentration in both cultivars. Ancymidol also significantly increased tuberisation under LD-dark for 6% sucrose in both cultivars. Tuberisation in cv. Jaerla was significantly higher than in cv. Baraka for any photoperiodic treatment in the presence or absence of ancymidol with 4, 6 or 8% sucrose. The photoperiod SD-SD resulted in the higher level of tuberisation for any combination of sucrose, cultivar and ancymidol. The possible role of ancymidol is discussed. 相似文献
5.
Cornelia J. M. Almekinders 《Potato Research》1993,36(2):97-105
Summary A knowledge of the pattern of flowering and seed production is required for the development of large-scale field production
of True Potato Seed (TPS). At the highland experimental station of the International Potato Center in Peru, data on flowering
and seed production were collected from three cultivars planted at three densities.
Main stems in which flowering was delayed ceased shoot growth at an earlier stage and produced fewer inflorescences. Inflorescences
produced later had fewer flowers, a lower berry set and yielded less seed. Inflorescences flowering at the same time performed
similarly, irrespective of their position on the plant. Increasing plant density resulted in cessation of shoot growth at
an earlier stage and concentrated inflorescence and flower production at primary positions of early-flowering shoots. With
cvs Renacimiento and Yungay a higher plant density increased the percentage of flowers produced in the first three weeks of
the flowering period, but with cv. Atzimba the effect of plant density on the distribution of flower production was off-set
by a slower stem development. 相似文献
6.
Summary Ware potatoes were produced from true potato seed by transplanting seedlings to the field in different growing periods to
evaluate environmental constraints of this production method in the Nile delta. In the autumn season, with high temperatures
and long-day conditions during seedling culture in the nursery and transplant establishment in the field, seedling development
was fast, and transplants resumed growth within 5 days of transplanting in the field. Tuber yields ranged between 120 and
160 dt ha−1. In the spring season, with low temperatures and short-day conditions during the initial growing phase, seedling development
in the nursery was slow and biomass partitioning between above ground organs (stems, leaves) and tubers was shifted towards
the tubers. This partitioning was further enhanced by transplanting the seedlings in the field. Seedlings recovered only slowly
from transplanting or died.
It is concluded that potato production via transplants is poor in the spring season when premature tuberization of seedlings
in the nursery leads to slow field establishment and low tuber yield. 相似文献
7.
Comparison of hydroponic and aeroponic cultivation systems for the production of potato minitubers 总被引:1,自引:0,他引:1
Summary Two different cultivation systems, aeroponics and hydroponics in greenhouse beds, were compared for the production of potato
minitubers. Plants in the aeroponic system showed increased vegetative growth, delayed tuber formation and an extended vegetative
cycle of about seven months after transplanting. Therefore in 1999, two production cycles were obtained with the hydroponic
system, but only one with the aeroponic system. However, compared with total production in hydroponics, the tuber yield per
plant in the aeroponic system was almost 70% higher and tuber number more than 2.5 fold higher. Average tuber weight was reduced
by 33% in the aeroponic system. Advantages and possible problems with the aeroponic system for minituber production are discussed. 相似文献
8.
Summary The potato is the most important horticultural crop in Argentina. Its commercial cultivation started in 1872/73 and production
greatly increased due to area and yield increases. This paper surveys potato production in Argentina. It describes and quantifies
distribution of crop area and production and the agro-ecological conditions in each growing area. Yield constraints are identified
and a yield gap analysis was performed using the LINTUL-POTATO simulation model. Possibilities for further yield improvement
are discussed. The survey established that important yield improvements were achieved in the country during the last 20 years,
mainly due to the use of high quality seed, new cultivars, improved fertilizers and irrigation techniques, and better control
of pests and diseases. However, the actual yield, at least for the regions studied, is still well below the attainable and
potential yields established with the LINTUL-POTATO model. Suggestions are made to improve further the potato yield in the
different growing areas. 相似文献
9.
Effect of haulm treatments on the formation of microsclerotia ofVerticillium dahliae Kleb. on potato
Summary In four pot experiments, potato plants of cv. Element were artificially infected withV. dahliae. At an early and a late harvest haulms were killed chemically, by burning or by various other treatments, including cutting
them into pieces of different lengths and keeping the debris on the soil surface or covering with soil. After 4 weeks the
plant material was air-dried and the number of microsclerotia per mg was determined.
At the early harvest, in two experiments, the chemical treatment yielded more microsclerotia than the cutting treatments.
Covering colonised haulm tissue with non-sterilised soil was effective in inhibiting microsclerotia formation. Shorter haulm
pieces led to fewer microsclerotia at the later harvest if the material was kept on the soil surface. The variation in microsclerotial
yield and in treatment effects among the different experiments was large. 相似文献
10.
Relationships between ground cover,intercepted solar radiation,leaf area index and infrared reflectance of potato crops 总被引:2,自引:0,他引:2
Summary In field trials with potato several methods determining the proportion of intercepted solar radiation by the crop were compared.
Non-destructive measurement of the proportion of ground cover with the aid of a grid correlated well with the proportion of
intercepted photosynthetically active radiation as measured with a tube solarimeter and with the leaf area index. Measurement
of the infrared reflectance of the crop proved to be an efficient and objective method to show differences between treatments.
Moreover, it showed a good correlation with ground cover and radiation interception until full closure of the canopy. Percentage
ground cover is useful for assessing intercepted solar radiation and leads to fewer errors in calculation of efficiency of
conversion into dry matter than the other methods. 相似文献
11.
Summary Potatoes were stored in three insulated bins having ventilation rates of 0.0190, 0.0306 and 0.0417 m3/s·t. The results showed that in the climate of northern Italy potatoes can be stored successfully at ventilation rates of
not less than 0.0306 m3/s·t resulting in product weight loss of less than 2.0% after 100 days' storage. The incidence of diseases and of sprouting
was very low at rates of 0.0306 and 0.0417 m3/s·t, but greater at 0.019 m3/s·t because of the higher tuber temperature. Laboratory tests simulating ambient conditions confirmed the validity of a thermodynamic
model simulating air-potato heat exchange. 相似文献
12.
Summary The relationships between the number of initial sprouts, the number of main stems, stolons and tubers per plant are depicted
in 4-quadrant figures. The number of sprouts per seed tuber varied because of different pre-sprouting conditions and/or because
of the use of different cultivars. Good linear relationships are shown between the numbers of sprouts and stems, stolons and
tubers, and sprouts and tubers, but especially between stolons and tubers within each trial with the one cultivar. When comparing
different experiments with the one cultivar the linear relationship between the numbers of stems and stolons disappeared.
When comparing different cultivars, no relation was found between the numbers of sprouts and stems. These two cases also led
to a statistically less significant relation between the number of sprouts planted and the number of tubers harvested. 相似文献
13.
Stephen L. Love Timothy J. Herrman Asunta Thompsonjohns Timothy P. Baker 《Potato Research》1994,37(1):77-85
Summary Potato tuber glycoalkaloid content was measured in response to nitrogen fertilizer rate, storage temperature, length of storage
period and cultivar. Cvs Gemchip, Norchip and Russet Burbank were grown with applied nitrogen fertilizer rates of 0, 168 or
336 kg/ha and then stored at either 4.4 or 10°C. Total glycoalkaloid content was determined one month before harvest, at harvest,
after three months of storage and after nine months of storage. Higher rates of nitrogen, higher storage temperature and a
period of storage all resulted in significantly (P<0.05) higher concentration of glycoalkaloids. The cv Norchip had higher glycoalkaloids than cvs Gemchip or Russet Burbank.
Only the storage period had more influence than the environment (difference between years). Significant (P<0.05) two-way interactions were detected for year x cultivar, year x nitrogen, storage period x cultivar and nitrogen x cultivar.
Most interactions were due to the unique responses of cultivars. 相似文献
14.
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
15.
Summary In pot culture experiments over 2 consecutive years, 20 potato genotypes of varying heat tolerance were grown under long day
conditions and heat stressed by being exposed to high (38 °C/21 °C mean day/night) temperature. The percent increase in mean
internode length of heat stressed plants over those grown at normal temperatue (25°C/16°C day/night) was correlated with the
percent tuber dry matter yield of the heat stressed plants (r=0.618, P=0.01). In the same 20 genotypes, grown under short
day conditions at normal temperature, the fraction of leaf bud cuttings exposed to high night temperature (23°C) that produced
tuber initials correlated with the percentage increase in internode elongation in stem cuttings exposed to 25°C compared with
those exposed to 15°C (r=0.680. P=0.01). Thus the relative changes in internode elongation are related to thermal tolerance,
and it is suggested that this can be used as a selection criterion for heat tolerance. 相似文献
16.
Summary The addition of a seaweed concentrate to tissue culture medium improved the quality of potato plantlets. Season, cultivar
and explant type affected the most beneficial concentration applied. Concentrations higher or lower than the optimum were
less beneficial or adverse to plantlet quality. Terminal buds were more sensitive to non-optimum seaweed application than
axillary buds. Decreased water loss from plantlets was one of the potential benefits of seaweed concentrate in vitro, thus
improving establishment after transplanting. 相似文献
17.
Summary Potato tubers were inoculated with two biotypes ofPhytophthora infestans then stored at 3,7, 10 and 15°C. Image analysis quantified average reflective intensity (ARI) of diseased tissue from cut
surfaces of sample tubers. Tuber tissue infection and infection rate were measured by calculating Mean ARI of samples. Average
tuber tissue infection and infection rate was minimal at 3°C (P.i.-US8 orP.i.-US1). Tuber tissue infection increased at temperatures >3°C, from 220 Mean ARI seven days after inoculation (dai) to 190–150
Mean ARI 50 dai (depending on cultivar and biotype ofP. infestans). Rate of tuber tissue infection caused byP.i.-US1 at 7°C was about zero in cv. Snowden but greater than −0.2 ARI day−1 (cvs Russet Burbank and Superior). Rate of late blight infection in tuber tissue generally increased with temperature from
−0.2 ARI day−1 (at 7°C) in all cultivars to a maximum of −0.8 ARI day−1 (10°C). 相似文献
18.
Summary The kinetics of accumulation of phytoalexins, glycoalkaloids and phenolics was studied in two potato cultivars differing in
their degrees of field resistance when infected withPhytophthora infestans. Tuber slices and leaves of cvs Pampeana INTA (high degree of field resistance, free of R genes) and Bintje (susceptible)
were infected with race C (complex race 1, 3, 5, 7, 11) ofPhytophthora infestans. Phytoalexins and phenolics accumulated in tuber and leaf tissues which had been inoculated. The levels of these compounds
in the susceptible cv. Bintje were relatively low and similar to those found before inoculation. Leaves of cv. Pampeana INTA
had a very high glycoalkaloid content, suggesting that glycoalkaloids may play a role in protection of leaves against the
fungus. However, we could find no correlation between resistance and glycoalkaloid content of tubers. Our results suggest
a major role of phytoalexins, phenolics and glycoalkaloids in the complex mechanisms of field resistance. 相似文献
19.
Summary Four experiments (three with four cultivars, one with twenty cultivars) investigated the effect of different storage temperature
regimes on the duration of dormancy of seed potatoes harvested immature. Regimes included constant temperatures (18 and 28°C),
hot pre-treatments (20 days at 28°C and subsequently 18°C) and cold pre-treatments (20 days at 2°C and subsequently 18°C).
Compared with 18°C, storage at 28°C slightly prolonged dormancy of some cultivars with a genetically short dormancy and shortened
dormancy by up to 45 days in cultivars with a long dormancy. Some tubers of one cultivar lost their ability to sprout after
storage at 28°C for 90 days.
A hot pre-treatment shortened dormancy by 2–3 weeks on average, for all cultivars examined. A cold pre-treatment shortened
dormancy by 2 weeks on average in some cultivars with a short dormancy and in all cultivars with a long dormancy. 相似文献
20.
Summary Preplant soil solarisation and mouldboard ploughing to a depth of 30 and 60 cm respectively were evaluated in two field experiments
for the control ofColletotrichum coccodes causing black dot of potato. Solarisation reduced disease incidence by 45% when tarping was done for eight weeks and temperatures
reached 56°C in the top 5 cm of soil. With a six week tarping period and lower maximum temperature (50°C) the reduction in
disease was a nori-significant 25%. Mouldboard ploughing to a depth of 30 cm reduced black dot by 34% and was twice as effective
as ploughing to a depth of 60 cm. 相似文献