植物精油对土耳其扁谷盗的驱避和熏蒸活性研究

本文研究了34种植物精油对土耳其扁谷盗成虫的驱避和熏蒸毒杀活性。结果表明,肉桂精油对土耳其扁谷盗成虫具有良好的驱避活性,24-48 h内,75%的个体选择了未添加植物精油的小麦;72 h后选择对照组的土耳其扁谷盗成虫降至63.33%,但仍有显著的驱避活性。孜然、松油和黑胡椒精油则对土耳其扁谷盗成虫表现出良好的引诱活性。在34种供试植物精油中,大蒜和芥末精油对土耳其扁谷盗成虫表现出强烈的熏蒸毒杀作用。当植物精油体积分浓度为10μL/L时,这两种植物精油在48 h内对供试害虫的校正死亡率保持在98%以上。进一步的毒力测试结果表明,在24 h、48 h及72 h处理时间下,大蒜精油对土耳其扁谷盗成虫的LC_(50)值分别为0.61、0.59及0.49μL/L,而芥末精油在相同处理时间条件下的LC_(50)值分别为4.35、4.28及4.16μL/L,大蒜精油对土耳其扁谷盗具有更强的熏蒸毒杀活性。     

4种植物精油对金银花贮藏期害虫锯谷盗的生物活性北大核心CSCD

采用滤纸药膜法和广口瓶熏蒸法,在室内测定了大蒜、生姜、花椒和八角茴香4种植物精油对金银花贮藏期害虫锯谷盗的生物活性。结果表明,4种植物精油对锯谷盗成虫均具有一定的驱避活性和熏蒸活性,平均驱避率分别为70.71%、60.64%、53.78%和66.33%,平均校正死亡率分别为60.47%、51.71%、47.01%和56.28%,差异达显著水平。4种植物精油的不同浓度和不同作用时间对锯谷盗成虫的驱避活性有显著差异,随着植物精油浓度的降低和作用时间的延长,各植物精油的驱避活性逐渐降低,浓度和时间的交互作用对驱避活性无显著影响。4种植物精油的浓度、不同作用时间以及它们的交互作用对锯谷盗成虫的熏蒸活性有显著影响,随着植物精油浓度的降低,熏蒸活性逐渐降低,随着作用时间的延长,熏蒸活性逐渐增强。进一步的毒力分析表明,大蒜精油的毒力最强,12 h的LC50值为6.01μL/L,随时间的延长,各植物精油的熏蒸毒力明显增强。这说明4种植物的精油对金银花贮藏贮藏期害虫锯谷盗具有一定的生物活性,具有开发为新型无公害杀虫剂的潜力。     

4种植物精油对金银花贮藏期害虫锯谷盗的生物活性

采用滤纸药膜法和广口瓶熏蒸法,在室内测定了大蒜、生姜、花椒和八角茴香4种植物精油对金银花贮藏期害虫锯谷盗的生物活性。结果表明,4种植物精油对锯谷盗成虫均具有一定的驱避活性和熏蒸活性,平均驱避率分别为70.71%、60.64%、53.78%和66.33%,平均校正死亡率分别为60.47%、51.71%、47.01%和56.28%,差异达显著水平。4种植物精油的不同浓度和不同作用时间对锯谷盗成虫的驱避活性有显著差异,随着植物精油浓度的降低和作用时间的延长,各植物精油的驱避活性逐渐降低,浓度和时间的交互作用对驱避活性无显著影响。4种植物精油的浓度、不同作用时间以及它们的交互作用对锯谷盗成虫的熏蒸活性有显著影响,随着植物精油浓度的降低,熏蒸活性逐渐降低,随着作用时间的延长,熏蒸活性逐渐增强。进一步的毒力分析表明,大蒜精油的毒力最强,12 h的LC50值为6.01μL/L,随时间的延长,各植物精油的熏蒸毒力明显增强。这说明4种植物的精油对金银花贮藏贮藏期害虫锯谷盗具有一定的生物活性,具有开发为新型无公害杀虫剂的潜力。     

植物精油对锈赤扁谷盗成虫熏蒸毒杀作用研究

为明确适用于防治锈赤扁谷盗的植物精油种类及其用量,本试验采用拌粮密闭熏蒸法,比较23种植物精油对锈赤扁谷盗成虫熏蒸毒杀活性差异,从中筛选出作用效果较好的精油种类进行熏蒸毒力测定。通过二次筛选结果表明,大蒜与芥末精油对锈赤扁谷盗成虫具有明显的熏蒸毒杀作用。进一步的毒力测试结果表明,在24 h、48 h、72 h处理时间下,大蒜精油对锈赤扁谷盗成虫的LC_(50)值分别为0.7827、0.7222、0.6478μL/L,而芥末精油在相同处理时间条件下的LC_(50)值分别为2.7581、2.6117及2.4619μL/L,大蒜精油对锈赤扁谷盗具有更强的熏蒸毒杀活性。     

长头谷盗对6种寄主谷粉及其挥发物的行为反应

利用Y型嗅觉仪和四臂嗅觉仪,测定了长头谷盗Latheticus oryzae (Waterhouse)对6种寄主谷粉的行为趋性反应,采用固相微萃取和气质联用(GC-MS)分析了其中3种寄主挥发物组分和含量,并测定长头谷盗对其中7种挥发物单体标样在5个浓度下的行为学反应,以期明确谷物挥发物在长头谷盗寄主定向行为中所起的作用.结果显示,6种寄主挥发物对长头谷盗雌雄成虫均具有显著的引诱作用,且雌雄个体间差异不显著;6种寄主之间分组比较时,长头谷盗的引诱强弱均显著的表现为全麦粉＞黄豆粉＞玉米粉＞荞麦粉＞小米粉＞高粱粉.选择全麦粉、黄豆粉和玉米粉进行分析时,3种寄主挥发物具有不同的化学图谱,且挥发物的相对含量差异较大,黄豆粉挥发物总量大于全麦粉和玉米粉;从组分来看,全麦粉挥发物中主要为烯醛类(37.46％),黄豆粉挥发物中主要为醇类(45.24％)和醛类(27.06％),玉米粉挥发物种主要为烷烃类(39.58％).7种寄主挥发物标样(100 ～ 1600μL/mL)中,除甲酸正己酯、二十烷和正十四烷对长头谷盗始终具有引诱作用外,正己醇、正己醛和反式-2,4-癸二烯醛分别在200～800、400 ～ 800和400 ～ 800 μL/mL时,才具有引诱作用;而反式-2-癸烯醛在高浓度(1600 μL/mL)下对长头谷盗具有趋避作用.综合分析表明,挥发性物质在长头谷盗对不同寄主谷粉的选择时具有重要的行为导向作用,且挥发性化合物的组成及浓度影响其引诱效果.     

木里柠檬果皮精油化学成分的研究

用毛细管气相色谱-质谱-计算机数据联用枝术、标准品叠加法和毛细管保留指数定性法分析了木里柠檬(Citrus Limun(L.)Burm.f.)的果皮精油化学成分。从蒸馏精油被分离出的78个色谱峰中鉴定了39种化合物,并测定了其相对含量。其主要成分是d-柠檬烯(69.4406％);;γ-萜品烯(8.3169);β-水芹烯(6.5947);芳樟醇(3.2172);香叶醛(1.7618);橙花醛(1.3422);α-蒎烯(1.3488);香叶烯(1.2371)和α-水芹烯(1.5753)。被鉴定的成分占总成分的99.1646％。比较了压榨法、蒸馏法和蒸馏-萃取法所得精油的化学成分,并与市售冷磨柠檬油和尤力克蒸馏油的主要成分进行了比较。     

天然杀虫剂β—水芹烯的合成

本文报导用环已烯经卤化反应、烷基化反应和Wittig反应合成天然杀虫剂β-水芹烯的方法。该合成方法原料易得,操作简便,反应条件温和,易于控制,适合于大量生产。中间体和产物经IR谱、~1HNMR谱、~(13)CNMR谱和MS分析证实了结构,产物总分离收率达38.37％。生物活性实验表明,产物对杂拟谷盗成虫具有较强的毒杀作用,LD_(50)=0.263μ1/头。     

大果木姜子精油化学成分的研究

用毛细管色谱-质谱-计算机联用,毛细管色谱-红外光谱-计算机联用,毛细管色谱保留指数和标准品叠加法,分析了大果木姜子(Cinnamomum migao H.W.Li)果实精油的化学成分。从分离出的63个峰中鉴定出47个成分,其中主要成分是1,8-桉叶素(23.75％),香桧烯(10.63％),柠檬烯(8.77％)和α-松油醇(6.36％)等。     

十二种药用植物乙醇提取物对谷蠹和赤拟谷盗成虫的驱避效应

采用滤纸药膜选择法研究了蛇床子、茵陈、萹蓄等12种药用植物乙醇提取物对谷蠹Rhizopertha dominica(Fab.)和赤拟谷盗Tribolium castaneum Herbst成虫的驱避效应。12种药用植物以蛇床子(Cnidium monnieri)提取物对谷蠹成虫的驱避效果最佳,786μg/cm2处理24h对谷蠹的驱避率达93%;茵陈(Artemisia capillaries)提取物对赤拟谷盗成虫的驱避效果最佳,用393μg/cm2处理72h的驱避率为95%,茵陈提取物以262μg/cm2放置7d后对赤拟谷盗成虫的驱避率可达Ⅴ级水平。茵陈提取物对赤拟谷盗的驱避持效期长、效果好,具有一定的开发前景。     

广藿香精油的杀虫作用及其活性成分分析

采用室内生物活性测定方法,研究了广藿香〔Pogostem on cablin(B lanco)Benth.〕全草精油的杀虫活性及其活性成分。结果表明,广藿香精油和广藿香酮对菜粉蝶(Preris rapaeL.)和小菜蛾(Plutella xylostellaL.)幼虫有较好的防治作用。使用2.5~40.0 mg.mL-1广藿香精油和1~10 mg.mL-1广藿香酮分别对菜粉蝶和小菜蛾幼虫进行饲喂实验,均表现出较强烈的拒食作用;广藿香精油和广藿香酮对4龄菜粉蝶幼虫毒杀作用的LC50值分别为104.28和32.20μg.mL-1。活性跟踪实验确证广藿香酮为广藿香精油的有效杀虫成分。     

Composition of essential oil in genetically transformed roots of <Emphasis Type="Italic">Ruta graveolens</Emphasis>

The composition of essential oil obtained by hydrodistillation from genetically transformed roots of common rue (Ruta graveolens L.) was analyzed. Using gas chromatography and complex gas chromatography-mass spectrometry, it was established that the major component of rue essential oil was a root-specific sesquiterpene geijerene comprising 67% of total amount of volatile compounds. In essential oil of cultured rue roots, furocoumarins characteristic of intact plant roots were found, viz. osthole, halepensin, and rutacultin. The content of essential oil in genetically transformed rue roots was 0.23% of root dry weight, which is comparable with that in the roots of intact plants. The long-term maintenance in the in vitro cultured rue roots of a capability for the synthesis of essential oil major components characteristic of intact plants allows their usage for studying the physiological activity of these volatile compounds and their putative role in the plant root interaction in biocenoses.     

Antimicrobial and insecticidal activities of essential oil isolated from Turkish Salvia hydrangea DC. ex Benth.

The hydrodistillated essential oil of Salvia hydrangea was analyzed by GC–MS. Fifty-four different components representing 95.9% of the compounds in the oil were identified. Camphor (54.2%), -humulene (4.0%), cis-sesquisabinene hydrate (2.8%), myrtenol (2.6%), β-bisabolol (2.2%) and 1,8-cineole (2.1%) were found to be predominant components. The oil was also characterized by relatively high amount of oxygenated monoterpenes (69.6%). The oil was tested for fungitoxic effects against 33 agricultural pathogenic fungi using in vitro microbial growth inhibition assays. The oil exhibited considerable antifungal activity against a broad spectrum of tested fungi. Antibacterial activity of the oil was determined against 30 bacterial strains using the disc diffusion method. The oil had a very wide spectrum of antibacterial activity. However, it was not as active as penicillin. The oil showed 68.3–75.0% mortality against adults of Sitophilus granarius and Tribolium confusum, the major pests of wheat and wheat products, respectively. It can be concluded that the oil of S. hydrangea has a potential against agricultural pathogenic fungi and two stored pests, S. granarius and T. confusum.     

Potential allelochemicals from the essential oil of Ruta graveolens

The essential oil of aerial parts of Ruta graveolens was obtained by hydrodistillation with a 0.74% yield on a dry weight basis. Thirty-eight components were identified by GC and GC-MS analyses. 2-Ketones predominated in the essential oil, with undecan-2-one (46.8%) and nonan-2-one (18.8%) as the main constituents. The essential oil and some of its constituents were tested for their allelopathic activity in vitro on radish germination and radicle growth in light and darkness. The essential oil and some of its minor constituents were effective and dose-dependent inhibitors of both the germination and radicle growth; 2-ketones are not active. The possible allelopathic activity of rue essential oil and some its isolated constituents is reported.     

Survey of fungal counts and natural occurrence of aflatoxins in Malaysian starch-based foods

In a survey of starch-based foods sampled from retail outlets in Malaysia, fungal colonies were mostly detected in wheat flour (100%), followed by rice flour (74%), glutinous rice grains (72%), ordinary rice grains (60%), glutinous rice flour (48%) and corn flour (26%). All positive samples of ordinary rice and glutinous rice grains had total fungal counts below 103 cfu/g sample, while among the positive rice flour, glutinous rice flour and corn flour samples, the highest total fungal count was more than 103 but less than 104 cfu/g sample respectively. However, in wheat flour samples total fungal count ranged from 102 cfu/g sample to slightly more than 104 cfu/g sample. Aflatoxigenic colonies were mostly detected in wheat flour (20%), followed by ordinary rice grains (4%), glutinous rice grains (4%) and glutinous rice flour (2%). No aflatoxigenic colonies were isolated from rice flour and corn flour samples. Screening of aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 using reversed-phase HPLC were carried out on 84 samples of ordinary rice grains and 83 samples of wheat flour. Two point four percent (2.4%) of ordinary rice grains were positive for aflatoxin G1 and 3.6% were positive for aflatoxin G2. All the positive samples were collected from private homes at concentrations ranging from 3.69–77.50 μg/kg. One point two percent (1.2%) of wheat flour samples were positive for aflatoxin B1 at a concentration of 25.62 μ};g/kg, 4.8% were positive for aflatoxin B2 at concentrations ranging from 11.25–252.50 μg/kg, 3.6% were positive for aflatoxin G1 at concentrations ranging from 25.00–289.38 μg/kg and 13.25% were positive for aflatoxin G2 at concentrations ranging from 16.25–436.25 μg/kg. Similarly, positive wheat flour samples were mostly collected from private homes. This revised version was published online in June 2006 with corrections to the Cover Date.     

Influence of Physicochemical Properties of Rice Flour on Oil Uptake of Tempura Frying Batter

The physicochemical properties of rice flour and wheat flour influenced the oil uptake of tempura frying batter. Rice flour was better than wheat flour in the overall quality and crispness of the fried tempura batter. Rice flour resisted oil absorption more than wheat flour, and a higher level of apparent starch amylose and higher consistency/breakdown ratio of the pasting properties led to a lower oil uptake of the batter. Super hard EM10 rice showed the highest apparent amylose content and higher consistency/breakdown ratio than the other flour samples, the batter from EM10 revealing the lowest oil content after frying among all the batters examined. The apparent amylose content, consistency/breakdown ratio and oil absorption index are proposed as useful guides for oil absorption when frying from among the physicochemical properties that influence the oil content of fried batter. Our proposal for the “oil absorption index” could be a simple, although not perfect method for estimating the oil content of batter flour.     

Influence of physicochemical properties of rice flour on oil uptake of tempura frying batter

The physicochemical properties of rice flour and wheat flour influenced the oil uptake of tempura frying batter. Rice flour was better than wheat flour in the overall quality and crispness of the fried tempura batter. Rice flour resisted oil absorption more than wheat flour, and a higher level of apparent starch amylose and higher consistency/breakdown ratio of the pasting properties led to a lower oil uptake of the batter. Super hard EM10 rice showed the highest apparent amylose content and higher consistency/breakdown ratio than the other flour samples, the batter from EM10 revealing the lowest oil content after frying among all the batters examined. The apparent amylose content, consistency/breakdown ratio and oil absorption index are proposed as useful guides for oil absorption when frying from among the physicochemical properties that influence the oil content of fried batter. Our proposal for the "oil absorption index" could be a simple, although not perfect method for estimating the oil content of batter flour.     

Phytase production by a thermophilic mould Sporotrichum thermophile in solid state fermentation and its potential applications

Phytase production by a thermophilic mould Sporotrichum thermophile Apinis was investigated in solid state fermentation (SSF) using sesame oil cake as the substrate. Scanning electron microscopy of the fermented sesame oil cake revealed a dense growth of the mould with abundant conidia. Glucose, ammonium sulphate and incubation period were identified as the most significant factors by Plackett-Burman design. The optimum values of the critical components determined by central composite design of response surface methodology for the maximum phytase production were glucose 3%, ammonium sulphate 0.5% and incubation period 120 h. An overall 2.6-fold improvement in phytase production was achieved due to optimization. Highest enzyme production (348.76 U/g DMR) was attained at a substrate bed depth of 1.5 cm in enamel coated metallic trays. The enzyme liberated inorganic phosphate from wheat flour and soymilk with concomitant dephytinization and liberation of soluble inorganic phosphate.     

Development and application of a method for analysis of lufenuron in wheat flour by gas chromatography-mass spectrometry and confirmation of bio-efficacy against Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

A new analytical method using gas chromatography with mass spectrometry (GC-MS) for the quantitative determination of lufenuron, a benzoylphenylurea (BPU) class of insecticide, from wheat flour has been developed and applied for time-dependent residue monitoring in treated wheat flour. The analyte was extracted from wheat flour by a single step solid-liquid extraction by using ethyl acetate and subsequently cleaned up using the Primary Secondary Amine as a sorbent prior to GC-MS analysis. The present method provides sufficient sensitivity as reflected by the values of limit of detection (LOD) and limit of quantification (LOQ), 5 ng/mL (S/N approximately 3) and 50 ng/mL (the lowest validation point on the calibration curve), respectively. The calibration curve showed an excellent linearity in the concentration range of 50-1000 ng/mL (r2=0.998). The average recovery for spiked samples at three concentrations (150, 300, and 450 ng/g) was 98.23+/-2.52% R.S.D. The method was applied for the determination of lufenuron residues in treated wheat flour samples. Simultaneous determination of bio-efficacy of lufenuron residues was also carried out against the red flour beetle, Tribolium castaneum to correlate the actual residual effect of lufenuron as detected by the analytical method, over a period of 3 months. The findings revealed that the residual concentration of lufenuron were neither uniform nor in descending order over a period of 3 months in wheat flour, possibly because of an uneven dispersal in the treated wheat which was subsequently milled into flour, as confirmed by GC-MS analysis. However, the residues of lufenuron were sufficient to produce 100% mortality of T. castaneum larvae up to 3 months. The results have been discussed in view of the potential of lufenuron as a candidate molecule for the control of stored product pests.     

Effect of culture substrates on virulence of Beauveria bassiana (Ascomycota: Cordycipitaceae) conidia against the browntail moth,Euproctis chrysorrhoea (Lepidoptera: Lymantriidae)

We studied the effect of different solid substrates on virulence of two Beauveria bassiana isolates against the browntail moth, Euproctis chrysorrhoea (L.) (Lep.: Lymantriidae). Conidia produced on wheat grains, wheat flour, wheat bran, rice flour, rice bran, rice paddy, corn flour, millet, and Sabouraud's dextrose agar with 1% yeast extract (SDAY) as control were compared. There were significant differences among these substrates for their effects on the virulence of produced conidia. Applying 10⁷ conidia/mL of B. bassiana EUT105, produced on rice bran caused the highest (84.9%) and on rice flour, the lowest (57.6%) mortalities. Bioassay on fifth-instar larvae using aerial conidia harvested from wheat grains, rice paddy, and SDAY indicated that conidia from wheat grains had the highest virulence while those from rice paddy, the lowest.     

Suppressive potential of bean (Phaseolus vulgaris) flour against five species of stored-product mites (Acari: Acarididae)

Previous research has demonstrated that legume proteins have insecticidal activity against stored-product pests, but activity against stored-product mites has not been tested. A study was therefore conducted to explore the potential of bean, Phaseolus vulgaris L., flour as novel botanical acaricide against five species of storage and dust mites: Acarus siro L., Aleuroglyphus ovatus (Troupeau), Caloglyphus redickorzevi (Zachvatkin), Lepidoglyphus destructor (Schrank), and Tyrophagus putrescentiae (Schrank). The effect of wheat, Triticum aestivum L., grain enriched with bean flour to eight concentrations (0, 0.01, 0.1, 0.5, 1, 2.5, 5, and 10%) on population growth initiating from the density of 50 mites per 100 g of wheat was recorded for 21 d under laboratory conditions (grain moisture 14.6% moisture content and 25 degree C in darkness). The enrichment of grain with bean flour suppressed the population growth of all tested species: 0.01% concentration reduced population growth of all tested species to >50% in comparison with the control population. The most sensitive species were A. siro and L. destructor, followed by T. putrescentiae and C. redickorzevi. The least sensitive species was A. ovatus. The terminal (i.e., after 21 d) density of mites positively correlated with bean flour concentration. The suppressive effect of bean flour was not linear but rather asymptotic. The results of this study are discussed in the context of the application of bean flour in integrated control of stored-product mites and the elimination of stored-product mite allergens.