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1.
A laboratory experiment was conducted with the poultry red mite Dermanysuss gallinae (De Geer) to assess the toxicity of a range of essential oils obtained from wild-growing plants in Tunisia to this pest. Details of the percentage essential oil yield from these plants were also recorded. For comparison, commercially sourced essential oil from Thymus vulgaris (L.) was also tested against D. gallinae after work elsewhere found this product to be acaricidal. Recently fed adult female D. gallinae were exposed to the essential oils at 0.1 mg oil/cm2 in Petri-dishes at 22 °C over a period of 24 h.Results showed that the yield of essential oil varied considerably depending upon the source plant. Whilst maximum yields of 0.5% were achieved, three of the seven wild plants selected provided yields of less than 0.1%. Similar variability was recorded with respect to the toxicity of the essential oils to D. gallinae. Three of the essential oils tested did not cause significant D. gallinae mortality (in comparison to the control). However, all other selected oils provided mortality levels statistically similar to the 90% mortality achieved with commercial T. vulgaris essential oil, with the oil from Pelargonium graveolens (L’Hér.) killing 100% of D. gallinae exposed to it. Essential oil from P. graveolens in particular may be suitable for further development as a D. gallinae acaricide alongside or in place of commercial thyme essential oil.  相似文献   

2.
The essential oils from 9 aromatic plants were tested on repellency and mortality of Meligethes aeneus adults. All the tested essential oils caused high mortality of M. aeneus adults in the tarsal tests. The lethal doses after 6 h exposure were ranged between 197 and 1508 μg cm−2. Essential oils obtained from Carum carvi and Thymus vulgaris were most efficient where LD50 was estimated as 197 and 250 μg cm−2, respectively.Repellency declined in all the essential oils as a function of time. The longest persistence time was determined for essences obtained from C. carvi and T. vulgaris where significantly the highest repellent index of 65.6% and 63.8%, respectively, was determined. Repellent index lower than 15% was determined for the remaining essential oils.  相似文献   

3.
The chemical composition of essential oils isolated from aerial parts of native populations of Origanum vulgare L. from northwestern Himalaya was investigated by enantioselective gas chromatography (enantio-GC), capillary-gas chromatography (capillary-GC) and GC–MS. Seventy compounds, which accounted for 84.9–97% of the oil composition, have been identified. The oils were allotted to two main groups; the first group had a high percentage of components belonging to the thymol/carvacrol biosynthetic pathway and the second was characterized by a different sesquiterpene composition and a high linalool and bornyl acetate percentage. Essential oils of O. vulgare populations from Rilkot and Dhanachuli areas in northwestern Himalaya were characterized by high monoterpenoids proportions as compared to Nainital and Bhowali populations, which were dominated by sesquiterpenoids. High proportions of thymol (29.2–82%) were found only in two populations. Composition of the samples collected from Dhanachuli area differed from Nainital and Bhowali collections by a unique presence of carvacrol. Notably, there were significant differences in the concentration of rest of the terpenes in all the collections. On enantio-GC, enantiomeric excess for (3R) (−)- and (3S) (+)-linalool, (S) (+)- and (R) (−)-terpinen-4-ol, (S) (−)- and (R) (+)-α-terpineol, (1S) (−)-bornyl acetate and (1S) (−)-borneol were established in populations from Bhowali and Dhanachuli area. Moreover, linalool type oregano may be useful in promoting wider commercial utilization of the biodiversity of this species.  相似文献   

4.
The hydrodistilled essential leaves and stems oils of Orthosiphon stamineus Benth were analysed by GC–MS/MS. Sixty nine compounds representing 97.6 and 97.4% of the total leaves and stems oils, respectively were identified, of which β-caryophyllene (24.0 and 35.1%), α-humulene (14.2 and 18.4%), β-elemene (11.1 and 8.5%), 1-octen-3-ol (8.2 and 7.0%), β-bourbonene (3.4 and 3.0%), β-pinene (2.1 and 1.7%), caryophyllene oxide (1.6 and 2.2%), camphene (1.6 and 1.3%) and limonene (1.2 and 1.1%) were the major compounds. Thus, the monoterpenes and sesquiterpenes were the predominant portions of the oils. Essential oils and methanol extract of O. stamineus and the derived fractions of hexane, chloroform, and ethyl acetate were tested for anti-fungal activity, which was determined by disc diffusion and minimum inhibitory concentration (MIC) determination methods. The oils, methanol extract and derived fractions of methanol extract displayed great potential of anti-fungal activity as a mycelial growth inhibitor against the tested phytopathogenic fungi such as Botrytis cinerea, Rhizoctonia solani, Fusarium solani, Colletotricum capsici and Phytophthora capsici, in the range of 49.3–70.3% and minimum inhibitory concentration ranging from 500 to 1000 μg/ml.  相似文献   

5.
The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most important and highly polyphagous pests of vegetables and other crops worldwide. Experiments were conducted in the laboratory and greenhouse to evaluate corn (Zea mays L.) as a banker plant for the predatory gall midge, Feltiella acarisuga (Vallot) (Diptera: Cecidomyiidae) to potentially control T. urticae. Choice and no-choice experiments were carried out to determine the host plant preference of an alternative prey, Oligonychus pratensis (Banks)(Acari: Tetranychidae) to corn and green bean (Phaseolus vulgaris L.). Results showed that O. pratensis adults strongly preferred corn as a host plant and posed no risk to green bean. F. acarisuga was found to fly at least 7.0 m to search for new preys on green bean plants, and over 176 F. acarisuga larvae per leaf were recorded at 14 d after dispersal. F. acarisuga proved to be an excellent predator of both T. urticae and O. pratensis. The predation by F. acarisuga to T. urticae and O. pratensis ranged from 43.7 to 67.9% and 59.2 to 90.3%, respectively, under laboratory conditions. In a non-cage study, 81.2% of T. urticae population was suppressed by F. acarisuga in reference to the control (cage treatment). The results showed that this banker plant system has potential for controlling T. urticae in greenhouse vegetable production.  相似文献   

6.
Effects of essential oils derived from garden thyme, Thymus vulgaris L., patchouli, Pogostemon cablin (Blanco) Benth., and lemon-scent gum, Corymbia citriodora (Hook.) K. D. Hill & L. A. S. Johnson, on mortality of eggs, first-instar nymphs, and pupae, and on adult oviposition, of Bemisia tabaci (Gennadius) biotype B were determined under laboratory conditions. Three concentrations of essential oils, 0.125%, 0.25% and 0.5% (v/v), were applied in contact toxicity experiments. In separate experiments, 0.5% essential oil treatment was tested for repellency. Greater mortality was observed with increasing dose of essential oils. No phytotoxicity was observed on plants treated with these essential oils. First-instar nymphs were more sensitive to essential oil treatments, compared with eggs and pupae. The greatest effect was found with essential oil extracted from T. vulgaris, which reduced the survival rate of B. tabaci by 73.4%, 79.0% and 58.2% after treatment of eggs, nymphs and pupae, respectively, as compared with controls. In no-choice tests, the cumulative survival rates of B. tabaci females treated with T. vulgaris, P. cablin and C. citriodora were 46.4%, 38.8% and 26.8% lower, respectively, as compared with controls. In choice tests, the mean numbers of eggs laid on P. cablin, T. vulgaris and C. citriodora oil-treated plants were 74.5%, 59.0% and 48.0% fewer, respectively, than on control plants. Based on this study, essential oil derived from T. vulgaris possessed the greatest contact toxicity, while P. cablin oil exerted the strongest repellency to B. tabaci. Hence, these two oils could be used as effective and environmentally sustainable bio-insecticides for the control of B. tabaci.  相似文献   

7.
The fatty acid profiles and tocopherol and phytosterol contents of crude oils of cress (Lepidium sativum L.) and field pennycress (Thlaspi arvense L.) are reported, along with yields from the corresponding seeds. The physical properties of these oils were also determined, which included oxidative stability, kinematic viscosity, viscosity index, low temperature fluidity, specific gravity, acid value, lubricity, and iodine value. The oil content of dried cress and field pennycress seeds was 22.7 and 29.0 wt%, respectively. The primary fatty acids found in cress oil were oleic (30.6 wt%) and linolenic acids (29.3 wt%), whereas field pennycress oil was principally composed of erucic (32.8 wt%) and linoleic (22.4 wt%) acids. Cress oil contained high concentrations of γ- (1422 ppm) and δ- (356 ppm) tocopherols, whereas α-tocopherol (714 ppm) was the primary tocopherol discovered in field pennycress oil. The overall tocopherol concentrations of cress and field pennycress oils were 1799 and 851 ppm, respectively. The primary phytosterols elucidated in cress and field pennycress oils were sitosterol and campesterol, with avenasterol also present in significant quantity in cress oil. The total phytosterol concentration in cress oil (14.41 mg/g) was greater than that in field pennycress (8.55 mg/g) oil. Field pennycress oil exhibited excellent low temperature fluidity, whereas cress oil was more stable to oxidation and over a range of temperatures displayed lower kinematic viscosities as well as a higher viscosity index. The acid and iodine values of field pennycress oil were lower than those for cress oil, but both oils had excellent lubrication properties.  相似文献   

8.
Cuphea (Cuphea viscosissima Jacq. × C. lanceolata f. silenoides W.T. Aiton, Lythraceae) is an oilseed crop, with medium-chain fatty acids, being developed for the North Central United States for industrial applications in the manufacture of soaps and detergents. Seed germination and seedling emergence of cuphea is often low when compared to the commercial crops. Identification of seed treatments to optimize seedling emergence and stand establishment for cuphea are important for commercial production. The objective of this study was to determine the effect of several fungicide treatments on pure live seed emergence (PLSE) of cuphea. Pure live seed emergence is defined as total seedling emergence adjusted by the germination of the seed planted. Field experiments were conducted at Prosper, ND and Glyndon, MN, in 2005 and 2006. Previous crop rotations were soybean [Glycine max (L.) Merr.]/hard red spring wheat (Triticum aestivum L.), and soybean/hard red spring wheat/sugarbeet (Beta vulgaris var. saccharifera L.) at Prosper and Glyndon, respectively, for both years. The experimental design was a randomized complete block with six treatments and four replicates. Treatments were: no fungicide applied (check treatment), captan, mefenoxam, fludioxonil + mefenoxam, azoxystrobin, and azoxystrobin + mefenoxam. Plant stand was counted and PLSE was calculated 10 to 15 d after seeding at all locations by counting emerged seedlings in the center two-plot-rows and adjusting PLSE for germination. Greenhouse experiments were conducted with soil treatments (pasteurized and non-pasteurized) and the same fungicide seed treatments as the field experiment. Pure live seed emergence, vigor index, and percent of diseased seedlings were recorded. Plant stand and PLSE were significantly greater for the seed treatments that had mefenoxam at the Glyndon, MN, environments, in which the previous crop was sugarbeet. Soil treatment (pasteurization) increased PLSE and vigor index. All fungicide seed treatments improved PLSE and vigor index and reduced damping-off compared to the untreated check. Results suggest that seed treatments including mefenoxam would be beneficial for commercial cuphea production.  相似文献   

9.
利用球孢白僵菌与赤眼蜂联合控制亚洲玉米螟已被证明具有较好的协同增效防治效果,但未见其他昆虫病原真菌与赤眼蜂共同施用下的相容性研究报道。本研究从田间采集的斜纹夜蛾幼虫僵虫中分离并鉴定出4株对亚洲玉米螟具有较高毒力的昆虫病原真菌菌株,分别为诺米曲霉(Aspergillus nomiae)、木贼镰孢(Fusarium equiseti)、莱氏绿僵菌(Metarhizium rileyi)和糙孢蓝状菌(Talaromyces trachyspermus),对亚洲玉米螟2龄幼虫半致死时间(LT50)分别为4.37、4.11、3.69和5.19 d。采用0.1%(w/v)的淀粉溶液作为吸附助剂可实现赤眼蜂单头蜂载菌量超过3.29万个孢子。进一步研究发现,这4种昆虫病原真菌对松毛虫赤眼蜂羽化及其对亚洲玉米螟虫卵寄生性无明显影响。  相似文献   

10.
Essential oils from 25 species of medicinal plants were tested as mycelial growth inhibitors against six important pathogenic and toxinogenic fungal species. An agar dilution method was used for determination of the inhibitory effect namely on Fusarium oxysporum, Fusarium verticillioides, Penicillium expansum, Penicillium brevicompactum, Aspergillus flavus and Aspergillus fumigatus. All essential oils used in our experiment evidently affected growth of these fungi. Minimum inhibitory concentration (MIC) was evaluated in the case of five essential oils showing the most significant antifungal activity. The superior antifungal activity was finally proved on the base of MIC values in the case of Pimenta dioica. The chemical composition of P. dioica essential oil was determined by means of GC–MS analysis.  相似文献   

11.
The essential oils obtained by hydrodistillation from the aerial parts of Tunisian native Hypericum perfoliatum L. (sect. Drosocarpium Spach.) and Hypericum tomentosum (sect. Adenosepalum Spach.) were analyzed by GC and GC–MS. Thirty-two compounds were identified in the essential oils of H. perfoliatum with α-pinene (13.1%), allo-aromadendrene (11.4%), germacrene-D (10.6%), n-octane (7.3%), α-selinene (6.5%) and β-selinene (5.5%) as main constituents. Sixty-seven components were identified in the oil of H. tomentosum with menthone (17.0%), n-octane (9.9%), β-caryophyllene (5.3%), α-pinene (5.2%), lauric acid (4.1%) and β-pinene (3.7%) as the most abundant components. Both oils were characterized by the presence of many components which could have numerous applications in food, pharmaceutical and perfume industries.  相似文献   

12.
球孢白僵菌对亚洲玉米螟毒力生测方法比较研究   总被引：1，自引：0，他引：1  
在球孢白僵菌不同浓度下,利用饲喂法和浸渍法测试球孢白僵菌对亚洲玉米螟3龄幼虫的致病力,建立球孢白僵菌对亚洲玉米螟毒力生测标准。结果表明,处理组中白僵菌浓度为105、106、107、108 CFU/mL时,采用饲喂法和浸渍法对3龄幼虫的校正死亡率、致死中时间（LT50）、致死中浓度（LC50）均没有显著性差异;饲喂法3龄幼虫的死亡率显著低于浸渍法。因此,球孢白僵菌对亚洲玉米螟毒力生测的常用方法可用饲喂法替代浸渍法,饲喂法试验过程简单,避免反复移动试虫引起的误差,毒力测试结果更可靠。  相似文献   

13.
The variation in the content and composition of Origanum majorana L. essential oil has been studied. Plant material has been harvested at four phenological stages (early vegetative, late vegetative, budding and full-flowering). Essential oil yield varied from 0.04 to 0.09% reached during the full-flowering stage. Analysis of the essential oils by GC and GC/MS revealed the presence of 38 components represented mainly by oxygenated monoterpenes (64.01–71.4%), monoterpene hydrocarbons (21.73–29.92%) and sesquiterpene hydrocarbons (1.47–4.05%). The main components were terpinen-4-ol (29.13–32.57%), cis-sabinene hydrate (19.9–29.27%), trans-sabinene hydrate (3.5–11.61%), γ-terpinene (2.11–8.20%), bornyl acetate (1.52–2.94%) and linalool (1.05–1.39%). On the other hand, phenolic contents varied from 2.706 to 6.834 mg/g of dry weight obtained during the later vegetative stage. RP-HPLC analysis of the methanolic extract of O. majorana L. dried aerial parts showed the predominance of phenolic acids during the early vegetative stage whereas flavonoids predominate during the other stages of growth. The main phenolic acids identified were trans-2-hydroxycinnamic, rosmarinic, vanillic, chlorogenic, gallic and cinnamic whereas the main flavonoids were amentoflavone, apigenin, quercetin, luteolin, coumarin and rutin. Results obtained showed that later vegetative stage is characterized by the highest contents of bioactive compounds and therefore it could be considered as the best stage for harvesting marjoram plants.  相似文献   

14.
The full whole culture (FWC), containing parasporal protein toxins of Bacillus thuringiensis israelinsis (Bti) and Bacillus sphaericus 2362 (Bs), either singly or in combination with plant oils and commercial insecticides, was tested against larval and adult stages of Culex pipiens mosquitoes under controlled laboratory conditions. In terms of LC50 values recorded after 24, 48, 72 and 96 h, the bacterial toxins showed high potency towards both larvae and adults of mosquitoes in a dose-dependent manner. Generally, the Bti toxin seemed to be more potent than the Bs toxin. For example, the Bti toxin showed a 24 h LC50 of 8.2 ppm against mosquito larvae compared to 13.6 ppm for the Bs toxin. In the adult bioassay, the obtained 24 h LC50 values were 0.064 and 0.085 mg/cm2, respectively for the two bacterial toxins. The bacterial toxins mixed with plant oils or insecticides at equitoxic doses (e.g., LC25 values) mostly showed potentiation effects, either against larvae or adults of the tested insect. Among a total of 14 paired mixtures, only the joint action estimated for the mixture of malathion + Bti or Bs was accounted as additively. Combining Bti or Bs endotoxins at LC0 with different plant oils and insecticides at LC50 concentration levels each, has resulted in considerable synergism against either larvae or adults. In the case of larval bioassays, the maximum synergistic factor (SF) obtained (ca. 2.0) was entitled to the mixture of Bti + spinosad. In the adult bioassays, the mixtures containing Curcuma longa or Melia azedarach oil extracts with Bti or Bs toxins achieved a SF accounted to 2.0. The results of the present study may be considered as an additional contribution to the area of joint toxicity of biocidal agents combining bacterial toxins, plant oils and traditional insecticides. The reached findings may encourage future research to elucidate its performance under practical field conditions.  相似文献   

15.
The essential oil of Clausena anisum-olens (Blanco) Merr. showed strong contact toxicity and repellency against Lasioderma serricorne and Liposcelis bostrychophila adults. The components of the essential oil obtained by hydrodistillation were determined by gas chromatography-mass spectrometry. It was found that the main components were myristicin (36.87%), terpinolene (13.26%), p-cymene-8-ol (12.38%), and 3-carene (3.88%). Myristicin and p-cymene-8-ol were separated by silica gel column chromatography, and their molecular structures were confirmed by means of physicochemical and spectrometric analysis. Myristicin and p-cymene-8-ol showed strong contact toxicity against L. serricorne (LD50 = 18.96 and 39.68 μg per adult) and Li. bostrychophila (LD50 = 20.41 and 35.66 μg per adult). The essential oil acting against the two grain storage insects showed LD50 values of 12.44 and 74.46 μg per adult, respectively. Myristicin and p-cymene-8-ol have strong repellent toxicity to Li. bostrychophila.  相似文献   

16.
Ritu Mawar  Satish Lodha   《Crop Protection》2009,28(10):812-817
In a two year field study, the effect of varying intensities of sub-lethal heating on the efficiency of Brassica amendments in controlling viable populations of Macrophomina phaseolina and Fusarium oxysporum f sp. cumini was determined in an arid region of India. After 30 d of dry summer exposure of pathogen infested soil, incorporation of mustard residues and oil cake (0.18% and 0.04% w/w) and then applying one irrigation caused significant reduction by 75.3–81.3% in viable counts of M. phaseolina that causes dry root rot of legumes and by 93.9% in counts of F.o. f. sp. cumini causing wilt of cumin (Cuminum cyminum L.) at 0–15 and 16–30 cm depths. Increasing duration of summer exposure to 60 d improved the reductions in viable propagules of M. phaseolina by 83.6–90.4% and in F.o. f. sp. cumini by 78.2–94.8% at same soil depths. At certain heat levels, reduction in viable population of Fusarium due to amendments and irrigation was greater than that recorded in Macrophomina. Significantly low levels of reduction in pathogenic propagules of Macrophomina (63.9–71.4%) and Fusarium (48.0–57.2%) under shade compared to unshaded conditions indicated that mild heating did not cause discernible weakening effect. In second season also, 89.2–91.5% and 78.5–95.8% reduction in counts of Macrophomina and Fusarium, respectively was achieved by the application of amendments after 60 d of summer exposure at 0–30 cm soil depth. These results suggested a new approach to improve the control of soil-borne plant pathogens in hot arid regions by combining prolonged sub-lethal heating, effective naturally available on-farm wastes as soil amendments and one summer irrigation.  相似文献   

17.
Two medicinally important seed oils viz. Mimusops elengi and Parkinsonia aculeata were analyzed for fatty acids distribution pattern in triacylglycerols using pancreatic lipase hydrolysis method. The seed oils contain high percentage of unsaturated acids (M. elengi 64.8% and P. aculeata 82.7%). The lipolytic data revealed that linoleic acid dominates at 2-position of triacylglycerols of all seed oils. M. elengi contain erucic acid in small amount (0.3%).  相似文献   

18.
The seed oils ofParkia biglobosa andParkia bicolor (Mimosaceae) have been analysed for their possible edible utility and to provide some physical data on both oils. The fatty acid composition of the oils was identified. Six major fatty acids were identified in the oil ofP. bicolor while five were identified in that ofP. biglobosa by Gas Chromatography (GC) and Gas Chromatography — Mass Spectroscopy (GC — MS). The two oils contained five similar fatty acids in almost the same ratios. Arachidic acid was the most abundant fatty acids (greater than forty per cent) in both oils. Other fatty acids in the oils were behenic, stearic, palmitic and linoleic acids. The sixth fatty acid inP. bicolor was an odd number of carbon atom and un unsaturated fatty acid (C20H37COOH) named bicolargic acid. The oils were also found to be non toxic.  相似文献   

19.
Yellow pigment concentration (YPC) in durum wheat is an important criterion in the assessment of semolina quality, particularly in determining the commercial and nutritional quality of end-products. Genetic variability of YPC and carotenoid components was analysed in 102 wild and cultivated tetraploid wheat accessions in two trials. Overall, modern cultivars showed significantly higher values of YPC compared to old cultivars and wild ssp. dicoccum and ssp. dicoccoides accessions. Total carotenoid concentration varied between 1.178 and 4.416 μg/g with an average of 2.460 μg/g. The portion of carotenoids amounted to 33.2% of the YPC in 80 wheat accessions examined in the 2006 trial. Lutein was the main component of carotenoids, followed by zeaxanthin and β-carotene. α-carotene and β-cryptoxanthin were minor components. Pigment concentration was negatively correlated with kernel weight and grain protein concentration. Significant positive correlations were found between b* index and YPC. Knowledge of the carotenoid composition and concentration is useful for wheat breeders in the development of cultivars with high yellow colour and enhanced phytochemical concentrations, and provides valuable information for evaluating contributions to health benefits from the consumption of durum wheat end-products.  相似文献   

20.
The aim of this research was to evaluate acute toxicity of the essential oil of leaves of Chinese chives, Allium tuberosum Rottler ex Spreng (Asparagales: Alliaceae) and its major constituents against Apolygus lucorum Meyer-Dür (Hemiptera: Miridae). The essential oil of A. tuberosum leaves was obtained by hydrodistillation and analyzed by gas chromatography and gas chromatography-mass spectrometry. The major constituents of the oil were sulfur-containing compounds, including allyl methyl trisulfide (36.24%), diallyl disulfide (27.26%), diallyl trisulfide (18.68%), and dimethyl trisulfide (9.23%). The essential oil of A. tuberosum leaves exhibited acute toxicity against Ap. lucorum with an LD50 value of 20.03 μg per adult. Among the main compounds, diallyl trisulfide (LD50 = 10.13 μg per adult) showed stronger acute toxicity than allyl methyl trisulfide (LD50 = 21.10 μg per adult) and dimethyl trisulfide (LD50 = 21.65 μg per adult). The LD50 value of diallyl disulfide against Ap. lucorum was 28.10 μg per adult. The results indicated that the essential oil of A. tuberosum and its major constituents may have a potential to be developed as botanical insecticides against Ap. lucorum.  相似文献   

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