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1.
Three species of birds and 5 species of mammals were captured in the wild from 2 plots in which mortality from naturally occurring nucleopolyhedrosis virus (NPV) among gypsy moth,Lymantria dispar (L.), larvae was 15% and 70%. Bioassays of intestinal contents showed that blue jays,Cyanocitta cristata (L.), towhees,Pipilo erythrophthalmus (L.), white-footed mice,Peromyscus leucopus (Rafinesque), redback voles,Clethrionomys gapperi (Vigers), raccoons,Procyon lotor (L.), and a chipmunk,Tamias striatus (L.), contained infectious (L.), and masked shrews,Sorex cinereus (Kerr), did not. Comparisons among mice and voles indicated that those collected from the plot in which the NPV mortality was greatest (70%) contained the most virus. We concluded that birds and mammals can passively transport infectious gypsy moth NPV in the wild.
Résumé Trois espèces d'oiseaux et 5 espèces de mammifères ont été capturées en 2 endroits où la mortalité due à la présence naturelle du virus de la nucléopolyhédrose (VNP) chez les larves deLymantria dispar (L.), était de 15% et de 70%. Le système digestif des geais bleux,Cyanocitta cristata (L.), guiraca à poitrine rose,Pipilo erythrophthalmus (L.), souris-au-pied-blanc,Peromyscus leucopus (Rafinesque), campagnols-au-dos-rouge,Clethrionomys gapperi (Vigers), ratons laveurs,Procyon lotor (L.) et d'un tamia,Tamias striatus (L.), était infecté par le virus alors que celui des rouges-gorges,Turdus migratorius (L.) et des musaraignes,Sorex cinereus (Kerr), ne l'état pas. Une comparaison entre les campagnols et les souris a indiqué que les animaux provenant de l'endroit où la mortalité par virose était la plus forte (70%) contenaient le plus de virus. Nous concluons que les oiseaux et les mammifères peuvent transporter passivement dans la nature les polyèdres nucléaires deL. dispar.


The work reported was funded in part by a U.S. Department of Agriculture sponsored program entitled, “The Expanded Gypsy Moth Research, Development and Applications Program”.  相似文献   

2.
Trivalent chromium (Cr3+) is essential for animal and human health, whereas hexavalent Cr (CrO4 2−) is a potent carcinogen and extremely toxic to animals and humans. Thus, the accumulated Cr in food plants may represent potential health hazards to animals and humans if the element is accumulated in the hexavalent form or in high concentrations. This study was conducted to determine the extent to which various vegetable crops absorb and accumulate Cr3+ and CrO4 2− into roots and shoots and to ascertain the different chemical forms of Cr in these tissues. Two greenhouse hydroponic experiments were performed using a recirculating-nutrient culture technique that allowed all plants to be equally supplied with Cr at all times. In the first experiment, 1 mg L−1 Cr was supplied to 11 vegetable plant species as Cr3+ or CrO4 2−, and the accumulation of Cr in roots and shoots was compared. The crops tested included cabbage (Brassica oleracea L. var. capitata L.), cauliflower (Brassica oleracea L. var. botrytis L.), celery (Apium graveolens L. var. dulce (Mill.) Pers.), chive (Allium schoenoprasum L.), collard (Brassica oleracea L. var. acephala DC.), garden pea (Pisum sativum L.), kale (Brassica oleracea L. var. acephala DC.), lettuce (Lactuca sativa L.), onion (Allium cepa L.), spinach (Spinacia oleracea L.), and strawberry (Fragaria ×  ananassaDuch.). In the second experiment, X-ray absorption spectroscopy (XAS) analysis on Cr in plant tissues was performed in roots and shoots of various vegetable plants treated with CrO4 2− at either 2 mg Cr L−1 for 7 d or 10 mg Cr L−1 for 2, 4 or 7 d. The crops used in this experiment included beet (Beta vulgaris L. var. crassa (Alef.) J. Helm), broccoli (Brassica oleracea L. var. Italica Plenck), cantaloupe (Cucumis melo L. gp. Cantalupensis), cucumber (Cucumis sativus L.), lettuce, radish (Raphanus sativus L.), spinach, tomato (Lycopersicon lycopersicum (L.) Karsten), and turnip (Brassica rapa L. var. rapifera Bailey). The XAS speciation analysis indicates that CrO4 2− is converted in the root to Cr3+ by all plants tested. Translocation of both Cr forms from roots to shoots was extremely limited and accumulation of Cr by roots was 100-fold higher than that by shoots, regardless of the Cr species supplied. Highest Cr concentrations were detected in members of the Brassicaceae family such as cauliflower, kale, and cabbage. Based on our observations and previous findings by other researchers, a hypothesis for the differential accumulation and identical translocation patterns of the two Cr ions is proposed. Received: 27 February 1998 / Accepted: 2 April 1998  相似文献   

3.
Antioxidant properties of essential oils   总被引:2,自引:0,他引:2  
By the method of capillary gas-liquid chromatography, we studied the antioxidant properties and stability during the storage of hexane solutions of 14 individual essential oils from black and white pepper (Piper nigrum L.), cardamom (Elettaria cardamomum L.), nutmeg (Myristica fragrans Houtt.), mace (Myristica fragrans Houtt), juniper berry (Juniperus communis L.), fennel seed (Foeniculum vulgare Mill., var. dulce Thelling), caraway (Carvum carvi L.), dry cinnamon leaves (Cinnamomum zeylanicum Bl.), marjoram (Origanum majorana L.), laurel (Laurus nobilis L.), ginger (Zingiber officinale L.), garlic (Allium sativum L.), and clove bud (Caryophyllus aromaticus L.). We assessed the antioxidant properties by the oxidation of aliphatic aldehyde (trans-2-hexenal) into the corresponding carbonic acid. We established that essential oils of garlic, clove bud, ginger and leaves of cinnamon have the maximal efficiency of inhibiting hexenal oxidation (80!–93%), while black pepper oil has the minimal (49%). Antioxidant properties of essential oils with a high content of substituted phenols depended poorly on their concentrations in model systems. We studied the changes in the composition of essential oils during the storage of their hexane solutions for 40 days in light and compared it with the stability of essential oils stored for a year in darkness.  相似文献   

4.
In a survey at 5 sites in southern Romania for parasites of pupalLymantric dispar (L.), 8 species were recovered: 3Tachinidae (Dip.); Blepharipa pratensis (Meigen),Parasetigena silvestris (Robineau-Desvoidy), andExorista larvarum (L.); 1Chalcididae (Hym.); Brachymeria intermedia (Nees); 4Ichneumonidae (Hym.); Theronia atalantae atalantae (Poda),Coccygomimus instigator (F.),C. turionellae turionellae (L.), andEphialtes compunctor compunctor (L.). This was the 1 st reported recovery ofE. c. compunctor from L.dispar. Overall parasitism was low, and it is unlikely that additional surveys in this area will yield new parasites for introduction into the U.S.
Résumé Cinq localités dans le sud de la Roumanie ont été prospectées pour recenser les parasites des nymphes deLymantria dispar (L.). Huit espèces de parasites ont été obtenues:Blepharipa pratensis (Meigen),Parasetigena silvestris (Robineau-Desvoidy),Exorista larvarum (L.),Brachymeria intermedia (Nees),Theronia atalantae atalantae (Poda),Coccygomimus instigator (F.),C. turionellae turionellae (L.), etEphialtes compunctor compunctor. Cette dernière espèce étant nouvelle surL. dispar. Le parasitisme total étant très bas, les auteurs en déduisent que des prospections supplémentaires dans cette région ont peu de chance d'être valables en vue de l'introduction aux états-Unis de nouvelles espèces contreL. dispar.
  相似文献   

5.
6-Methoxy-2-benzoxazolinone (MBOA) inhibited germination of rice (Oryza sativa L.), wheat (Triticum aethiopicum Jakubz), rye (Secale cereale L.), onion (Allium cepa L.), wild oat (Avena fatua L.), barnyard grass [Echinochloa crus-galli (L.) Beauv.], ryegrass (Lolium rigidum Gaudin), cress (Lepidium sativum L.), lettuce (Lactuca sativa L.), tomato (Lycopersicum esculentum Mill.), carrot (Daucus carota L.) and amaranth (Amaranthus retroflexus L) and the inhibition increased with increasing MBOA concentrations. MBOA also inhibited the induction of α-amylase in these plant seeds and the inhibition increased with increasing MBOA concentrations. There were variations in sensitivity of these plant species to MBOA, and species of family Poaceae (barnyard grass, wild oat, rice, rye, ryegrass, and wheat) were less sensitive to MBOA than the other plant species.  相似文献   

6.
Dehydrins are characterized by the consensus KIKEKLPG amino acid sequence found near the carboxy terminus, and usually repeated from one to many times within the protein. A synthetic peptide containing this consensus sequence was used to produce specific antibodies that recognize dehydrins in a wide range of plants. This range covered two families of monocots, viz. Gramineae (Hordeum vulgare L., Triticum aestivum L., Zea mays L., Oryza sativa L.) and Liliaceae (Allium sativa L.), and five families of dicots, Malvaceae (Gossypium hirsutum L.), Solanaceae (Lycopersicon esculentum L.), Brassicaceae (Raphanus sativus L.), Fabaceae (Vigna unguiculata L.), and Cucurbitaceae (Cucumis sativus L.). Two families of gymnosperms, Pinaceae (Pinus edulis Engelm.) and Ginkgoaceae (Ginkgo biloba L.), were also included. For several plants in which dehydrin cDNA and genomic clones have previously been characterized, it now appears that the dehydrin family of proteins is larger, and the regulation of dehydrin expression much more complex, than earlier studies have shown.  相似文献   

7.
The potential of four co-occurring ladybirds, Coccinella septempunctata (L.), Coccinella transversalis (F.), Cheilomenes sexmaculata (F.), and Propylea dissecta (Mulsant), as predators of the pea aphid, Acyrthosiphon pisum (Harris) was investigated. Larger ladybirds were more voracious while smaller ones had higher consumption indices and were more efficient converters of food.  相似文献   

8.
Iron-chlorosis deficiency may occur when an iron-inefficient genotype is grown on calcareous soil. One way to correct the problem is to modify the genotype by plant breeding. Cultivars have been released for oat (Avena byzantina C. Koch), sorghum [Sorghum bicolor (L.) Moench], dry bean (Phaseoulus vulgaris L.), and soybean [Glycine max (L.) Merr.]. Progress is being made in peanut (Arachis hypogea L.), forage species such as clovers (Trifolium sp.) and bluestems (Botriochloa sp.), and pepper (Capsicum annuum L.). Screening of rootstocks is done on citrus (Citrus sp.), mango (Manguifera indica L.), and avocado (Persea americana Mill.).  相似文献   

9.
Germination of the following wild plant seeds was studied: bilberry (Vaccinium myrtillus L.), cowberry (V. vitis-idaea L.), bog bilberry (V. uliginosum L.), black crowberry (Empetrum hermaphroditum Hagerup), bearberry (Arctostaphylos uva-ursi (L.) Spreng.), bunchberry (Chamaepericlymenum suecicum (L.) Aschers. et Graebn.), cottongrass (Eriophorum polystachion L.), goldenrod (Solidago lapponica With.), fireweed (Chamaenerion angustifolium (L.) Scop.), marsh cinquefoil (Comarum palustre L.), cloudberry (Rubus chamaemorus L.), and Scots pine (Pinus sylvestris L.). The seeds were collected at different distances from the source of industrial air pollution (Severonickel smelter complex, Murmansk region). The task was the assessment of potential possibility of restoring corrupted north forest plant communities via seed propagation. By the response of reproductive structures to stressor, investigated species were divided into 3 groups: tolerant (members of the genus Vaccinium and Ch. angustifolium); moderately tolerant (C. palustre, E. polystachion, A. uva-ursi, and R. chamaemorus); and sensitive (P. sylvestris, E. hermaphroditum, and S. lapponica). Laboratory seed germinability of Vaccinium species was high (> 90%) regardless of the levels of Ni and Cu accumulation in the seeds and the index of technogenic load, whereas this index in E. hermaphroditum and P. sylvestris seeds was significantly reduced with the increase in the heavy metal contents in the seeds. The greenhouse experiments with the seeds of three Vaccinium species collected in the background area and in the zone of the highest pollution and germinated on the forest litter from the same sites and observation for seedling development allow us to conclude that a potential possibility of these species to seed propagation are not limited by their seed viability even under conditions of the highest technogenic load. In sites of environment pollution, the high metal content in the upper soil layer is the main factor limiting plant seed propagation.  相似文献   

10.
Summary In a 3 year field study, the effect of two rotations, paddy (Oryza sativa L.), wheat (Triticum aestivum L.), mung (Phaseolus aureus L.) and corn (Zea mays L.), wheat (Triticum aestivum L.), mung (Phaseolus aureus L.) on wheat yield and chemical, physical and biological properties of soil was evaluated. Grain yield of the wheat sown after paddy during 1972–73, 1973–74 and 1974–75 was lesser by 0,300 and 390 kg/ha respectively than that of the wheat following corn. The reduction in the yield of wheat was attributed to relatively higher NPK removal by paddy, greater immobilization of N applied to wheat and deterioration of soil physical conditions in the paddy field. Total NPK removal by paddy average 131 kg/ha more than that by corn. Sharp increase in bacterial population of soil during early growth of wheat that followed paddy and the concurrent less available N in soil and low N content in wheat plants suggested that the N applied to wheat was immobilised to organic form. The increase in soil bulk density and particle dispersion ratio and decrease in water storage in deeper soil layers in the paddy field probably restricted the root proliferation and growth of wheat.  相似文献   

11.
The Verret basin was formerly an overflow area between the Mississippi and Atchafalaya rivers and contains about 41,000ha of forested wetlands. Water levels are rising at the rate of over 1 cm/year in this area, and the forests are subjected to longer and deeper flooding. Tree growth, litterfall, and species composition were monitored across a flooding gradient during January 1985–December 1986. The driest area was only 20 cm higher in elevation than the wettest area, but the structure of the forest changes greatly over this range. The drier area was dominated by sweetgum (Liquidambar styraciflua L.), oaks (Quercus spp.), and sugarberry (Celtis laevigata Willd.), while green ash (Fraxinus pennsylvanica Marsh.), red maple (Acer rubrum L.), and baldcypress (Taxodium distichum (L.) Rich.) were dominant in the wetter area. Green ash and bitter pecan (Carya aquatica (Michaux. f.) Nutt.) were found in all plots, but these two species are under severe stress in the more flooded area as evidenced by dead and dying trees. Stem wood production increased from 1985 to 1986 in the driest (392 to 473 g/m2/yr) and wettest (199 to 399 g/m2/yr) plots, but remained relatively unchanged in the transitional area (386 to 380g/m2/yr). Leaf litter production decreased across the gradient from dry to flooded plots during both years. Over 40% of the litterfall in the drier plot was from flood-tolerant shrub species. In the flooded plots, red maple and baldcypress were major contributors to total litterfall. Increased flooding of dry bottomland forests in the future could lead to decreased litterfall and increased tree death over the entire watershed.  相似文献   

12.
Summary A highly specific rabbit antiserum raised against peroxidase (PRXa) from petunia (Petunia hybrida) was used to investigate the antigenic relatedness of peroxidases in the Solanaceae. After SDS-PAGE of crude leaf extracts from a large number of species of this family, immunoblotting revealed that cross-reacting protein bands were present in all species tested. In order to determine whether these protein bands represent peroxidases, the peroxidase isoenzymes in thorn apple (Datura stramonium L.), tobacco (Nicotiana tabacum L.), sweet pepper (Capsicum annuum L.), potato (Solanum tuberosum L.), and tomato (Lycopersicon esculentum Mill.) were further analyzed. Immunoblots obtained after native PAGE revealed that the antiserum only recognized fast-moving peroxidase isoenzymes that are localized in the apoplast. Despite their serological relatedness, these peroxidases differed with respect to heat stability and apparent molecular weight. Differences in avidity for the petunia PRXa antiserum were suggested by immunoprecipitation with antibodies bound to protein A-Sepharose. The antiserum did not react with peroxidases from horseradish (Armoracea rusticana Gaertn., Mey and Scherb), turnip (Brassica napus L.), African marigold (Tagetes cresta L.), maize (Zea mays L.), and oats (Avena sativa L.). Apparently, the Solanaceae contain orthologous genes encoding the fast-moving anionic peroxidases homologous to petunia PRXa.  相似文献   

13.
The n-hexane-, acetone- and water-soluble fractions obtained from an aqueous acetone extract of lemon balm (Melissa officinalis L.) shoots inhibited the germination and the growth of roots and shoots of cockscomb (Amaranthus caudatus L.), cress (Lepidium sativum L.), crabgrass (Digitaria sanguinalis L.), timothy (Phleum pratense L.), lettuce (Lactuca sativa L.) and ryegrass (Lolium multiflorum Lam.). The inhibitory activity of the water-soluble fraction was the greatest, followed by that of acetone- and n-hexane-soluble fractions in all bioassays. The effectiveness of these fractions on the roots was greater than that of the shoots of the test plants. Significant reductions in the germination and growth of the roots and shoots were observed as the extract concentration increased. Such rate-dependent responses of the test plants to the fractions suggest that each fraction might contain allelochemical(s), but that the greatest potential was in the water-soluble fraction.  相似文献   

14.
Genetic transformation of perennial tropical fruits   总被引:4,自引:0,他引:4  
Summary Genetic transformation provides the means for modifying single horticultural traits in perennial plant cultivars without altering their phenotype. This capability is particularly valuable for perennial plants and tree species in which development of new cultivars is often hampered by their long generation time, high levels of heterozygosity, nucellar embryony, etc. Most of these conditions apply to many tropical and subtropical fruit crops. Targeting specific gene traits is predicated upon the ability to regenerate elite selections of what are generally trees from cell and tissue cultures. The integrity of the clone would thereby remain unchanged except for the altered trait. This review provides an overview of the genetic transformation of perennial tropical and subtropical fruit crops, i.e., citrus (Citrus spp.), banana and plantain (Musa groups AAA, AAB, ABB, etc.), mango (Mangifera indica L.), pineapple (Ananas comosus L.), avocado (Persea americana Mill.), passion fruit (Passiflora edulis L.), longan (Dimocarpus longan Lour.), and litchi (Litchi chinensis Sonn.).  相似文献   

15.
The growth inhibitory effect of cucumber (Cucumis sativus L.) plants after crop harvested was investigated. Aqueous methanol extracts of the cucumber plants inhibited the growth of roots and shoots of cress (Lepidium sativum L.), lettuce (Lactuca sativa L.), alfalfa (Medicago sativa L.), ryegrass (Lolium multiflorum L.), timothy (Pheleum pratense L.), crabgrass (Digitaria sanguinalis L.), Echinochloa crus-galli (L.) Beauv and Echinochloa colonum (L.) Link, and increasing the extract concentration increased the inhibition. These results suggest that cucumber plants may possess allelopathic activity. The aqueous methanol extract of cucumber plants was divided into ethyl acetate and aqueous fractions, and the growth inhibitory activity of ethyl acetate fraction was greater than that of aqueous fraction. Thus, ethyl acetate fraction was further purified and a main allopathically active substance in the fraction was isolated and determined as (S)-2-benzoyloxy-3-phenyl-1-propanol by spectral data. This substance inhibited root and shoot growth of cress seedlings at concentrations greater than 10 μM, and the concentration required for 50% inhibition of root and shoot growth was 21 and 23 μM, respectively. These results suggest that (S)-2-benzoyloxy-3-phenyl-1-propanol may contribute to the growth inhibitory effect of cucumber plants and may play an important role in cucumber allelopathy. Thus, cucumber plants may be potentially useful for weed management in a field setting. An erratum to this article can be found at  相似文献   

16.
The antiproliferative activity of extracts from cell suspensions of strawberry (Fragaria x ananassa Duch.), blackberry (Rubus fruticosus L.), red raspberry (Rubus idaeus L.) and strawberry-tree (Arbutus unedo L.) on murine B16-F10 melanoma cells was investigated. To enhance the synthesis of the bioactive compounds, various elicitors, i.e. temperature (cold and cold/warm cycle), light (blue and red) and increased nitrogen concentration, were also applied to the cell cultures to evaluate the effects on their antiproliferative activity. The extracts from all the species reduced murine melanoma cell proliferation (between 30% and 38% relative to the control) and an improvement of antiproliferative activity on murine melanoma cells, relative to the un-elicited berry suspensions, was shown by the extracts from strawberry and strawberry-tree cells treated with red and blue light.  相似文献   

17.
Five cereals and two related grasses were tested for adventitious shoot production from tissue cultures using methods concordant with those reported to be successful for cereals. The five cereals I wheat (Triticum aestivum L.), oats (Avena sativa L.), and maize (Zea mays L.) Pioneer hybrid 3369A, the Bolivian race Pororo and the Equadorian race Chococenõl were all found to proliferate in culture through an aberrant root-like mechanism of growth which had the external appearance of callus. Two related species, teosinte (Zea mexicana Reeves and Mangelsdorf) and tripsacum (Tripsacum dactyloides L.), were less successful in culture, but grew in the same way. Oats, and probably Pororo and Chococeño, initiated presumptive shoot meristems directly from root vascular tissues within this root-like growth. Hybrid maize and wheat initiated no shoot meristems and produced only roots. The occasional shoot production observed in wheat was discounted as simple carryover of existing shoot apices from the primary embryo cultures. This study suggests that the incidence of shoot regeneration in cultures of these cereals may be related more directly to adventitious bud formation on roots than to any controlled de novo organogenesis from undifferentiated callus.  相似文献   

18.
The effect of soil temperature on the net photosynthetic rate was studied by the method of multifactor analysis at early growth stages of narrow-leaved lupine (Lupinus angustifolius L.), white cabbage (Brassica capitata Lisg.), spring wheat (Triticum aestivum L.), cucumber (Cucumis sativus L.), tomato (Lycopersicon esculentum Mill.), and cotton (Gossypium hirsutum L.) plant species and cultivars contrasting in their heat demand. The optimum level of the net photosynthetic rate was observed in a wide range of soil and air temperatures, from cold- to heat-hardening temperatures, irrespective of the sign of the temperature gradient, whereas the magnitude and sign of the temperature gradient favorable for the highest potential net photosynthetic rate were species- and cultivar-specific and were not related to the cold tolerance of a species or cultivar.  相似文献   

19.
During 2002–2004, three laboratories in Canada and France collaborated to improve initiation of somatic embryogenesis (SE) in jack pine (Pinus banksiana Lamb.), eastern white pine (P. strobus L.), maritime pine (P. pinaster Ait.), and Scots pine (P.␣sylvestris L.), giving particular attention to the effects of (1) N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) versus various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and benzyladenine (BA), (2) differences in basal nutrient media, i.e., macro- and microelements, and (3) gelling agent concentration. The work was carried out separately at␣each laboratory, but the details of media compositions were shared and tested on their respective species. Results indicate that the developmental stage of the zygotic embryo (ZE) and genotype effects had a large influence on SE initiation, and that genetic effects were consistent over time. Different species responded differently to PGR types and concentration, basal nutrient media, trace elements, and their combinations. Currently, our best initiation rates based on a selected group of genotypes, optimal development stage of ZE, and medium are 3.9% for jack pine, 54.6% for eastern white pine, 76.2% for maritime pine, and 19.7% for Scots pine.  相似文献   

20.
Airborne pollen and spore levels were monitored at seven sites in New Zealand using the Intermittent Cycling Rotorod sampler during the summer of 1988/1989. Grasses formed the major component of atmospheric pollen levels during spring and summer at every locality. Peak levels of grass and total pollen occurred during December or late November, with a slight latitudinal lag apparent at the more southern sites. Highest levels were recorded at the smaller rural centres of Gore and Kaikohe and the lowest at the larger urban centres of Auckland, Christchurch and Wellington. We make a first approximation of the likely risk to hayfever and allergic asthma patients at each of the seven centres. For example, significantly higher grass pollen levels were experienced at Kaikohe on 44% and 65% of days during November and December, compared with just 15% and 8% at Auckland. By recording the flowering seasons of the principal allergenic grass species at each locality, we determined the potentially allergenic grasses contributing to peak pollen levels, the most ubiquitous being tall fescue (Festuca arundinacea Schreb.), ryegrass (Lolium perenne L.,L. multiflorum Lam.), cocksfoot (Dactylis glomerata L.), Yorkshire fog (Holcus lanatus L.) and sweet vernal (Anthoxanthum odoratum L.). Corresponding author. Deceased.  相似文献   

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