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1.
Summary Alpha-terthienyl, a phototoxic thiophene derivative from species in the Asteraceae reduced feeding and growth of the phytophagous lepidopteran,Euxoa messoria, when incorporated into artificial diets at a concentration of 100 ppm. The effects of this substance were substantially enhanced by including photosensitizing near-UV radiation in the trials. The results suggest that the phototoxic properties of this secondary substance provide significant protection to the plants containing it.This work was supported by NSERC and Agriculture Canada.  相似文献   

2.
Summary Treatment of post-feeding larvae of the cabbage maggotDelia radicum with methoprene did not affect the capacity of the insect to pupate, but suppressed eclosion to the adult stage. The concentration of hemolymph trehalose was significantly decreased by methoprene treatment, although hemolymph protein and amino nitrogen levels were unaffected.19 December 1986The authors are grateful to D. C. Read of the Research Centre, Agriculture Canada, Charlottetown, P.E.I., Canada for supplying eggs ofD. radicum for the stock colony. TheD. radicum colony was maintained at the Agriculture Canada Research Station, St. John's West, Newfoundland, Canada. The sample of methoprene was donated by Zoecon Corp., Palo Alto, California, U.S.A. This research was supported by a grant from the Natural Sciences and Engineering Research Council of Canada (Operating grant A6679).  相似文献   

3.
Summary T. theileri has been isolated from primary cultures of bovine retina and subcultered successfully for 2 passages in sub-confluent cultures. When cultures reached confluency no trypomastigotes or epimastigotes could be detected and attempts to recover trypanosomes from these cultures were unsuccessful. The presence of intracellular forms could not formally be excluded.We wish to thank Dr S. Dershko, Division of Meat Inspection, Health of Animals Branch, Department of Agriculture (Canada) and Intercontinental Packers, Ltd. for their assistance in obtaining the freshest possible specimens. The skillful technical assistance of Mrs J. Graham is also gratefully acknowledged. This investigation was supported by the M. R. C. of Canada.  相似文献   

4.
Summary Examination ofD. brownii, a stock-poison of Western Canada, revealed that the principal toxin was methyllycaconitine: a potent neuromuscular blocking agent which appears to act competitively at nicotinic receptors.We thank the University of Calgary, The National Research Council of Canada, and the Alberta Agriculture Department, for financial assistance.  相似文献   

5.
Summary Fruits of tomato (Lycopersicon esculentum Mill. cv. Fireball) were harvested 32 and 37 days after anthesis and dipped for 30 min in 10,000 ppm daminozide. Ripening of treated fruits, as manifested by an advancement in ethylene production and the respiratory climacteric, was accelerated by up to 7 days over control fruit.Acknowledgment. This investigation was supported by Agriculture Canada and the Ontario Ministry of Agriculture and Food.  相似文献   

6.
Summary Dense cells ofRubus chamaemorus L. (cloudberry) root meristems have been characterized by histochemical staining reactions at light and electron microscope levels. Presence of polyphenolic compounds in the cellular matrix contribute to the density of the dense cells.This research was supported by an operating grant from Agriculture Canada.  相似文献   

7.
Résumé Dans deux variétés deMétrosideros polymorpha Gaud. (Myrtaceae), nous avons trouvé les favanoides suivants: arabinoside-3, galactoside-3, rhamnoside-3-quercetine, et arabinoside-3, thamnoside-3-myricetine; en outre, deux glycosides en moindre quantité.

Acknowledgment. The authors are grateful to Prof.Siegel and MissCorn, University of Hawaii, for plant materials and to the N.R.C. of Canada for financial support.  相似文献   

8.
Summary (E,E)-10,12-Hexadecadienal has been identified as a component of the sex pheromone of the female spiny bollworm moth,Earias insulana, by gas-chromatographic, electroantennographic and microchemical studies of abdominal tip extracts and entrained volatiles from female moths.This work was carried out under Ministry of Agriculture, Fisheries and Food licence HH 11599/139, issued under the Destructive Pests and Diseases of Plants Order 1965.  相似文献   

9.
Summary Two African species ofAspilia (Asteraceae), which are used medicinally by man and which are eaten by wild chimpanzees in an unusual manner, were found to contain the potent antibiotic thiarubrine A as a major leaf phytochemical. Its presence in leaf material strengthens the view that the feeding behavior of wild chimpanzees is related to special physiological or pharmacological effects on the animals.  相似文献   

10.
Summary A study of the pituitary of the newt,Notophthalmus viridescens, during limb regeneration indicated no observable changes in histology or ultrastructure of any of the cells of the pars distalis when compared with the pars distalis of unamputated control newts.This investigation supported by a grant from the National Research Council of Canada to S.R. Scadding.  相似文献   

11.
Summary Restriction endonuclease analysis was used to compare the genome of mouse adenovirus (MAd) strains FL and K87. Large differences were found between theKpn I,PaeR7,Pvu I,Sal I andSma I restriction profiles of the prototype strains. MAd-FI and MAd-K87 thus represent two distinct species of mouse adenovirus.This work was supported by grants from the Fonds pour la formation de chercheurs et l'aide à la recherche and the Natural Sciences and Engineering Research Council of Canada.  相似文献   

12.
Summary The intakes of pelleted alfalfa by hungry sheep were depressed in a rectilinear manner in relation to the amount of water (0–800 ml) added to a balloon in the reticulum (p<0.005). Since the consumption of water by thirsty sheep was not altered by these treatments, the reduction in food intake produced by distending the reticulum was a specific response. The intakes of food were not significantly affected by distending the rumen with 800 ml water in a balloon so it is possible that the amount of fill in the reticulum rather than in the rumen may be important in signalling satiery in sheep.Acknowledgments. The technical assistance of Karen Gordon and funding from the National Research Council of Canada and the Ontario Ministry of Agriculture and Food are gratefully acknowledged.  相似文献   

13.
Summary The saliva of the blood-feeding bugRhodnius prolixus contains at least 11 proteins, and has Ca2+-dependent apyrase activity. The activity has a broad pH optimum between pH 7 and 9, and is inhibited by Mg2+. Polyacrylamide gel electrophoresis and gel filtration suggest the possibility of at least 2 enzymes responsible for the activity.This work was supported by the National Science and Engineering Research Council of Canada. We are grateful to D. F. Mettrick for use of equipment, and to R. Hewson for invaluable assistance.  相似文献   

14.
Summary IAA oxidase activity increased concomitant with root initiation during 16–52 h, in all cultures, thus showing the necessity of an active IAA oxidase for root initiation inPhaseolus mungo hypocotyl cuttings. The increase being very sharp in IAA alone, but less in all other cultures. The role of sucrose in root initiation via IAA oxidase activity has been discussed.The research has been partly financed by a grant from the US Department of Agriculture. One of us (R.N.C.) is thankful to the CSIR, India, for financial assistance.  相似文献   

15.
Summary The mycotoxin alternariol (3,4,5-trihydroxy-6-methyldibenzo [a] pyrone) but not alternariol monomethyl ether (3,4-dihydroxy-5-methoxy-6-methyldibenzo [a] pyrone) is phototoxic toEscherichia coli in the presence of near UV light (320–400 nm). The phototoxicity bioassays with a DNA repair-deficient mutant ofE. coli suggested that DNA may be the molecular target for photo-induced toxicity of alternariol. Interactions between alternariol and double-stranded, supercoiled DNA suggest that alternariol interacts with DNA by intercalation. No DNA breakage was detected in this system; however, alternariol forms a complex and cross-links double-stranded DNA in near UV light. These results suggest that alternariol is a new phototoxic, DNA-intercalating agent and is a DNA cross-linking mycotoxin in near UV light.Acknowledgment. Dr Albert Stoessl (Agriculture Canada, London, Ontario, Canada) generously provided a mixture of alternariol and alternariol monomethyl ether, and made many helpful suggestions. Dr Ashwood-Smith (University of Victoria, Victoria, British Columbia, Canada) kindly supplied the microorganisms through Dr G.H.N. Towers (University of British Columbia, Vancouver). We gratefully acknowledge the gifts. It is a pleasure to acknowledge the able assistance of Mr S. Tallevi.  相似文献   

16.
Summary Proteins immunologically related toRhynchosciara americana larval protein 10 occur in the hemolymph and ovaries of five different fly species of the genusRhynchosciara. Electrophoretic analyses showed these proteins to have a mol.wt similar to that of theR. americana protein 10 (43,000), e.g. theR. hollanderi protein 44,300, theR. milleri protein 45,500.  相似文献   

17.
Summary The octopamine, dopamine and noradrenaline content of the brain of the locust,Schistocerca gregaria has been determined using sensitive radiochemical-enzymatic assays. Octopamine and dopamine are present in high concentration but the noradrenaline content is only 1/25 that of octopamine. Both reserpine and fusaric acid (a dopamine--hydroxylase inhibitor) produce a significant depletion of the octopamine stores.The author is a M.R.C. of Canada Fellow. Thanks are due to Drs.A. A. Boulton, A. V. Juorio, andP. H. Wu for helpful discussion.  相似文献   

18.
Summary Workers and queens of the eastern yellowjacket,Vespula maculifrons, are attracted to the artificial long-range attractant pheromone of the predaceous pentatomid,Podisus maculiventris. A 11 mixture of linalool or -terpineol and (E)-2-hexenal is as attractive toV. maculifrons workers as the pheromone.We thank A.S. Menke of the Systematic Entomology Laboratory, USDA, for identifying the yellowjackets. Mention of a company name does not imply endorsement by the US Department of Agriculture.  相似文献   

19.
Summary Larvae ofNyctemera annulata Boisduval ingest pyrrolizidine alkaloids fromSenecio spathulatus A. Rich. which subsequently appear in the adult months and their eggs; the acquisition of the alkaloids by a parasite of theN. annulata larvae provides a further illustration of their ability to persist in insects.Acknowledgments. We thank Dr R. Yamdagni of the Chemistry Department, University of Calgary, Canada, and Dr O. Madsen of the Organic Chemistry Department, The Technical University of Denmark, Lyngby, Denmark, for much help with the MS data collection. We are also very grateful to Dr C.C.J. Culvenor, CSIRO Animal Health Lab., Parkville, Victoria, Australia, who most generously provided us with authentic reference specimens of pyrrolizidine alkaloids.  相似文献   

20.
Zusammenfassung Es wird gezeigt, dass wasserlösliche Extrakte aus Tabakrauchkondensaten vegetative Keimlinge auf Kallusstücken aus Stämmen von haploiden Tabakpflanzen (Nicotiana tabacum) induzieren und dass der gleiche Effekt mit Kinetin und 3-Indolessigsäure erzielt werden kann.

This study was carried out under contract No. 12-14-100-341(73) with the Agricultural Research Service, U.S. Department of Agriculture, administered by the Eastern Utilization Research Development Division, Philadelphia.

The authors are thankful to Dr.R. B. Griffith, Director, Tobacco and Health Research Institute, University of Kentucky, for critical review of this paper and valuable suggestions.  相似文献   

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