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1.
Previous work showed that, in the presence of root excretioci of certain crucifen, larvae of the potato-root eelworm do not emerge from the cysts when stimulated by potato-root excretions; a similar lack of response is also shown in the presence of dilute solutions of allyl isothiocyanate, the mustard oil of black mustard. The present paper describes a small-scale field trial in which this mustard oil is applied with peat to the drills at the time of planting. An increase in yield of about 100% resulted from a dressing of the oil equivalent to o.1 cwt/acre.  相似文献   

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3.
Samples of root diffusate from sprouts ( Brassica oleracea var. gemmifera ), swedes ( B. napus var. napobrassica ), rape kale ( B. napus var. arvmsis ), and white mustard ( Sinupis alba ), all stimulated larval emergence from cysts of Heterodera cruciferae. When mustard-root diffusate was added to leachings from the other species tested there was no apparent effect on larval emergence. In half dilution with tap water, mustard leachings were comparable in activity with similar dilutions of leachings from the other species under observation. Leachings from soil were less active than those from the four species of plants tested, but showed significant activity in comparison with tap water.
The form of the hatching curve was studied using diffusates from both sprouts and mustard roots, and in each case when cumulative hatch was plotted against time on a logarithmic scale, the sigmoid curve obtained closely fitted the theoretical sigmoid calculated from a probit analysis of the data.
Estimates were obtained of the log activity values of leachings from the four species of plants tested and from soil, following an examination of the dilution curves for mustard and sprouts root diffusates. These curves were closely parallel with one another, and it was therefore considered justifiable to derive log activity values for these root diffusates, although the cysts used in the hatching tests and the root-diffusate samples were each obtained from a single source. For this reason some caution is perhaps called for in the interpretation of the results presented in this paper.  相似文献   

4.
The potato varieties Epicure and Doon Star permitted the production of fewer and smaller cysts of Heterodera schachtii on their roots than the varieties Golden Wonder and Majestic, when all were grown under standard conditions. Under the stimulus of potato-root excretion the number of larvae which emerged from Epicure and Doon Star cysts was less than that from Majestic or Golden Wonder cysts of the same volume. Accepting Lapage's (1938) criteria of resistance to nematode infestation in animals and applying them to plants, it is concluded that this deleterious effect of the variety on the eelworm is probably of the nature of a degree of resistance to eelworm attack specific to each variety and is physiological and not anatomical in action. Of the varieties tested, Epicure is judged the most resistant, closely followed by Doon Star. Majestic is fairly susceptible but not so much so as Golden Wonder on which the eelworm forms large cysts that are extremely productive of larvae.  相似文献   

5.
Plasma levels and urinary amino acid excretions were estimated by high-performance liquid chromatography in 15 control subjects and 36 stone formers (SFs) classified according to the stone type: (1) 22 cases with calcium oxalate stones; (2) four cases with pure uric acid stones; (3) 10 cases with magnesium-ammonium phosphate stones, either pure or mixed with apatite. Some types of stones (namely oxalate and uric acid calculi) are mainly formed as a result of a metabolic deficiency that may affect the amino acid metabolism, and thus may be reflected in the urinary amino acid pattern. Data demonstrated clearly that there is a general tendency towards decreased amino acid excretions in all SFs with all types of stones. As a whole, one can observe a higher percentage of patients with calcium oxalate and phosphate calculosis, who have low urine excretions of amino acids; about 50% are the SFs with lower urine excretion of serine, glycine, taurine and i-leucine; the high percentage of patients with CaOX calculi shows lower urine excretions of tyrosine and ornithine.  相似文献   

6.
Certain dilute solutions of organic silver compounds, e.g. 0.001% silver proteinate, acting for a short time on cysts of the potato strain of Heterodera schachtii , cause increased numbers of larvae to emerge from the cysts when the latter are transferred to potato root excretion. More prolonged exposure of cysts to these solutions tends to result in a toxic effect which is also produced by more concentrated solutions. It is concluded that many more eggs in H. schachtii cysts are mature and capable of hatching than can be accounted for by ordinary larval liberation brought about by means of root excretion alone. Increasing periods of pre-treatment of cysts in tap water tend to produce increases in larval emergence, although this stimulation is probably of a different type from that given by silver compounds.  相似文献   

7.
Results are presented of experiments on the effect of low temperature and of soil type upon the potato-root eelworm, Heterodera schachtii.
In some experiments exposure of cysts, to low temperatures had a definite lethal effect, but in others the cysts were unharmed. The reason for this variation was not apparent. Exposure of the larvae of die nematode to even a relatively slight degree of frost resulted in the death of the larvae, provided mat die surrounding medium was completely frozen. In this respect the larvae appear to differ markedly from those of the beet strain of H. schachtii. That the larvae had actually been killed was shown by the fact that they produced no cysts on the roots of potato plants and also by their almost immediate absorption of iodine.
It was confirmed that H. schachtii cysts produced on the roots of potato plants grown in a heavy medium are smaller in size and fewer in number than those formed on the roots of plants grown in a light medium. The heavy medium used was pure clay, the light one pure sand, while equal numbers of eelworm larvae served in each case as inoculum. The difference in cyst size was significant, and fewer larvae emerged from the cysts formed in clay than from those produced in sand.  相似文献   

8.
Hatching experiments were carried out with potato-root eelworm cysts ( a ) from plant pots containing different numbers of earthworms, and ( b ) from worm casts. Cysts from these sources differed from controls in the following ways: (1) more larvae emerged, per cyst; (2) the larvae emerged sooner; (3) more cysts produced larvae; (4) the number of emerging larvae, per cyst, increased with the number of earthworms.
Examination of the contents of cysts isolated from worm casts showed that, compared with controls, 145% more eggs hatched; it also indicated some of the limitations of the 'per-cyst' basis of expressing results.  相似文献   

9.
The effects of gibberellic acid (GA3), potassium nitrate (KNO3), prechilling, temperature, salt stress and osmotic potential on seed germination and sowing depth on seedling emergence and burial depth on seed viability of hoary cress (Cardaria draba (L.) Desv.), were studied in a series of laboratory, glasshouse and outdoor experiments. The optimal temperature for hoary cress seed germination was 20°C, both in light/dark and darkness regimes. Seed germination of hoary cress at 400 ppm concentration of GA3 in a light/dark regime was maximal. Potassium nitrate concentrations increased the percentage of germination in comparison with the control treatment. Increasing the duration of dry prechilling to 30 and 45 days promoted the seed germination of hoary cress. Germination of hoary cress markedly decreased as salt and drought stress increased. Seed germination of hoary cress occurred at a range of pH from 3 to 11. Seedling emergence significantly decreased as planting depth increased. Total seed viability decreased with increasing burial depth. The maximum increase in mortality occurred in seeds that were buried at 5‐cm depth.  相似文献   

10.
Seedlings of Norway spruce (Picea abies L.) have been found to synthesize anthocyanins in the root tips as well as in the hypocotyls upon irradiation with white light when kept at 4°C for 6–8 days. In addition, it has also been found that the elongation and the geotropic curvature of spruce roots are dependent on the light conditions. The course of the geotropic curvature in spruce roots containing anthocyanins has been followed during a period of 5 h, in which the seedlings were geotropically stimulated continuously in the horizontal position. When the stimulation was performed in white light and in darkness at 21°C, significantly larger curvatures were observed in the roots pretreated at 4°C in darkness than in the roots containing anthocyanins. The specific curvature (curvature in degrees per mm elongation), however, was approximately the same in both types of roots stimulated in white light. This was due to a retarded elongation of the roots pretreated with light at 4°C and containing anthocyanins. A smaller difference in elongation rate between roots with and without anthocyanins was observed in the dark than in the light, but even in the dark the anthocyanin-containing roots grew more slowly than roots without anthocyanins. In order to find out if it is the anthocyanin content or the illumination which affects the elongation and geotropic curvature in the roots, a series of similar experiments was performed using cress seedlings grown at 4°C in light or darkness. Roots of cress seedlings cultivated under conditions which would induce anthocyanin formation in spruce roots exhibited the highest geotropic responses both in light and darkness as compared to cress seedlings grown at 4°C in darkness. As in the case of spruce roots an increase in elongation was observed in cress roots illuminated during the geotropic stimulation. These similarities in the behaviour made it relevant to compare the development of the geotropic curvature in cress and spruce roots.  相似文献   

11.
The penetration, development, and reproduction of a California population of the sugarbeet cyst nematode, Heterodera schachtii, was observed on cultivars of cabbage (Brassica oleracea), phacelia (Phacelia tanacetifolia), buckwheat (Fagopyrum esculentum), oilseed radish (Raphanus sativus), and white mustard (Sinapis alba). With the exception of the nonhost, phacelia, all were readily penetrated by second-stage juveniles of H. schachtii. After 38 days at 25 C, no cysts were observed on phacelia cv. Angelia or on the oilseed radish cv. Nemex and Pegletta. Cyst production was low (<2.5 cysts/plant) on the buckwheat cv. Tardo and Prego and most of the oilseed radish cultivars. Cyst production was intermediate (5-14 cysts/plant) on most of the white mustard cultivars, and high on cabbage (20-110 cysts/plant). In microplot studies conducted over 133 days (approx. 450 degree-days, base 8 C), the reproductive index for H. schachtii was greater than 1.0 for cultivars of phacelia, oilseed radish, and white mustard as welt as in fallow treatments, indicating the need for further research on the use of these crops under field conditions.  相似文献   

12.
KORDAN  H. A. 《Annals of botany》1979,43(2):173-177
Cruciferous seedlings germinated on glass-distilled water andon barbital manifested normal root and shoot geotropisms whereastwisted roots and shoots were evident in seedlings germinatedon amobarbital and secobarbital, the roots often being completelysuspended in the air. The marked difference in germination anddevelopment behaviour of cress and white mustard seedlings germinatedon barbital compared with that on amobarbital and secobarbitalindicate that the Meyer-Overton principle of drug potency andlipid solubility was operative in both species of germinatingseedlings. Lepidium sativum L., Sinapsis alba L., seed germination, geotropism, barbiturates  相似文献   

13.
Abnormally enlarged muscle fiber cells of ring form were incidentally detected in transverse sections of muscles of the common squirrel monkey during microscopic investigation of the composition of muscle fibers. Longitudinal sections showed slender capsule-like cysts in the sarcoplasm. Detailed examination revealed these cysts to be those ofSarcocystis. Among the three types of muscle fiber cells that compose the skeletal muscle, staining with Sudan black B revealed that this parasite selectively infested type II white fibers with a large diameter and a high glycogen content.  相似文献   

14.
1. The hatching factor of the potato-root eelworm was concentrated from potato-root leachings by adsorption on charcoal. The crude material, extracted from charcoal with acetone, was purified by partition between ethyl acetate and m-potassium dihydrogen phosphate, and ethyl acetate and a solution of potassium metabisulphite (disulphite). Neutral material was removed by extraction from phosphate buffer at pH7.8. The yield of purified material, after chromatography on silica, DEAE-cellulose and Perlon columns, was 18mug./l. of potato-root leachings, and 0.04% by weight of the acetone-soluble material extracted from charcoal; 20% of the activity of the original potato-root leachings was recovered. 2. The purified material was a colourless gum. On paper chromatograms it gave a single weakly fluorescing spot, which reacted with 2,4-dinitrophenylhydrazine and aniline-xylose reagents. It was confirmed that the hatching factor is an acid, and it is inactivated at values above pH9. Other properties were a ready oxidation by permanganate and reaction with certain carbonyl reagents. Colour tests for alpha- and beta-unsaturated gamma-lactones were negative. The hatching factor showed no light-absorption maxima at wavelengths above 210mmu; absorption bands in the infrared region (670-4000cm.(-1)) are given. Our purified material, although a gum, gave a similar hatch to a ;crystalline' product at 640 times its concentration.  相似文献   

15.
Traditional breeding methods based on inbreeding are difficult to implement in the case of Sinapis alba (white mustard) because this plant displays high levels of self-incompatibility. More rapid progress in breeding could be possible if biotechnological methods and in vitro cultures were used. However, white mustard is not readily amenable to biotechnological treatment. Seeds of traditional S. alba cultivars (e.g., Nakielska) are characterized by high levels of glucosinolates and erucic acid. However, a new Polish variety of white mustard (Bamberka) possesses low erucic acid content in the oil. The main goal of the study was elaboration of a plant regeneration system via in vitro culture of hypocotyl and cotyledon explants from low and high erucic acid-containing white mustard cultivars. In these experiments, a simple system for in vitro regeneration of white mustard was developed, with the aim to promote maximum formation of shoots within a short period of time. Traditional and improved cultivars of S. alba showed comparable capacity for shoot development from hypocotyl-derived and cotyledon-derived explants. The two types of cultivars were characterized by essentially equivalent shoot regeneration responses, being slightly higher in hypocotyl than the cotyledonary explants. A greater influence on shoot regeneration from hypocotyl explants was observed on medium supplemented with 4.4 μmol 6-benzylaminopurine, 0.57 μmol indole-3-acetic acid, and a low concentration of kinetin (4.6 μmol). This technique will allow for rapid generation of sufficient plant material for further use in a variety of white mustard breeding projects.  相似文献   

16.
In this research, hardaliye a traditional fermented Turkish beverage was produced by modification of traditional method and investigated for some properties.Lactobacillus sanfrancisco (LB16),Lactobacillus acetotolerans (LB21),Lactobacillus pontis (LB26),Lactobacillus paracasei ssp.paracasei (LB30) as starter cultures were added into pasteurised grape juice. Production of hardaliye using either white or black mustard seeds withLactobacillus paracasei ssp.paracasei LB30 reached to minimum pH value. It was determined that, lactobacilli which was added as starter cultures and mustard seeds had no clear effect on decrease in total sugar contents. During the 7-day fermentation period, lactic acid bacteria count in hardaliye, produced using white mustard seeds, changed from 4. 60, 4.69, 4.47 and 4.79 log CFU/ml to 4.92, 4.94, 5.90 and 6.83 log CFU/ml respectively and in the other samples, produced using black mustard seeds changed from 4.25, 4.07, 4.07 and 4.20 log CFU/ml to 6.60, 7.20, 6.54 and 6.77 log CFU/ml respectively.  相似文献   

17.
The development of a method using wax layers to simulate the effect of strong soil crusts on seedling emergence is described. Wax layers of different strengths were prepared by melting together white soft paraffin and paraffin wax in different proportions. The wax discs were placed above seeds planted in wet, but well-aerated sand in controlled environments. The effect of adding charcoal to the wax discs to prevent transmission of light was also tested. When wax layer penetrometer pressure was 0.2–0.25 MPa, light transmission greatly decreased the final emergence of carrot, but not onion seedlings. Penetrometer pressures above 0.25 MPa greatly decreased emergence through black wax layers in both carrot and onion. The presence of 2–4 mm stones immediately below wax layers (to simulate aggregates) decreased the emergence of onion shoots through wax layers with penetrometer pressures of 0.25 MPa and above. The emergence of carrot and onion seedlings from wax layers was compared to emergence in the field from different soil types and aggregate sizes. In both laboratory and field experiments, carrot gave better emergence than onion when emergence was relatively poor. Results were consistent with the hypothesis that mechanical impedance is a major factor in poor crop emergence in temperate conditions.  相似文献   

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19.
When humans will settle on the moon or Mars they will have to eat there. Food may be flown in. An alternative could be to cultivate plants at the site itself, preferably in native soils. We report on the first large-scale controlled experiment to investigate the possibility of growing plants in Mars and moon soil simulants. The results show that plants are able to germinate and grow on both Martian and moon soil simulant for a period of 50 days without any addition of nutrients. Growth and flowering on Mars regolith simulant was much better than on moon regolith simulant and even slightly better than on our control nutrient poor river soil. Reflexed stonecrop (a wild plant); the crops tomato, wheat, and cress; and the green manure species field mustard performed particularly well. The latter three flowered, and cress and field mustard also produced seeds. Our results show that in principle it is possible to grow crops and other plant species in Martian and Lunar soil simulants. However, many questions remain about the simulants'' water carrying capacity and other physical characteristics and also whether the simulants are representative of the real soils.  相似文献   

20.
STUDY OBJECTIVE--To compare responses of blood pressure to the calcium antagonist verapamil and the beta blocker metoprolol in black compared with white diabetics with hypertension and to monitor urinary albumin excretion in relation to fall in blood pressure. DESIGN--Double blind, placebo controlled, random order crossover trial with four week placebo run in period and two six week active phases separated by a two week placebo washout period. SETTING--Outpatient department of a general hospital in a multiethnic health department. Patients--Diabetic patients with hypertension. Four dropped out before randomisation; 25 black and 14 white patients completed the trial. INTERVENTIONS--Patients given slow release verapamil 120 mg or 240 mg twice daily with placebo or metoprolol 50 mg or 100 mg twice daily with placebo. Treatment for diabetes (diet alone or with oral hypoglycaemic drugs) remained unchanged. END POINT--Comparison of changes in blood pressure in the two groups taking both drugs. MEASUREMENTS AND MAIN RESULTS--Metoprolol had little effect on blood pressure in black patients (mean fall 4.0 mm Hg systolic (95% confidence interval -2.5 to 10.4 mm Hg), 4.3 mm Hg diastolic (-0.8 to 9.5)) but more effect in white patients (mean falls 13.4 mm Hg (0.1 to 26.7) and 10.6 mm Hg (4.5 to 16.7) respectively). Verapamil was more effective in both groups, with mean falls of 8.8 mm Hg (2.4 to 15.0) and 8.1 mm Hg (5.0 to 11.2) in black patients and 19.1 mm Hg (5.4 to 32.9) and 11.4 mm Hg (0.9 to 22.0) in white patients. Heart fate fell significantly in black patients taking metoprolol, which suggested compliance with treatment. Metabolic variables were unaltered by either treatment. Plasma renin activity was low in both groups after metoprolol treatment, but change in blood pressure could not be predicted from baseline plasma renin activity. Urinary albumin:creatinine ratio was independently related to baseline blood pressure but not significantly changed by treatment. CONCLUSIONS--beta Blockers alone are not effective in treating hypertension in black diabetics. Verapamil is effective but less so than in white patients. As yet no ideal monotherapy exists for hypertension in black patients.  相似文献   

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