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1.
以斜纹夜蛾侧沟茧蜂及其最适寄主斜纹夜蛾2龄幼虫为研究对象,研究斜纹夜蛾侧沟茧蜂寄生对斜纹夜蛾幼虫几种行为的影响。研究结果表明:被寄生的斜纹夜蛾幼虫在生长发育后期的位移、取食和分布均发生了一系列显著变化,被寄生的斜纹夜蛾幼虫生长发育后期位移和取食均极显著受到抑制,被寄生的斜纹夜蛾幼虫生长后期在叶片背面和其它地方的分布比例均显著高于未被寄生幼虫。在被寄生的1~6 d,被寄生幼虫爬行速度均大于未被寄生的幼虫。  相似文献   

2.
Extracts of 12 Asteraceae were tested on Spodoptera frugiperda (Lepidoptera: Noctuidae) and on their parasitoids Telenomus remus (Hymenoptera: Scelionidae) and Trichogramma pretiosum (Hymenoptera: Trichogrammatidae). The plants Lychnophora ericoides and Trichogonia villosa were toxic for 97.7 ± 0.15% of one-day-old eggs of S. frugiperda and Lepidaploa lilacina for 72.0 ± 2.50% for two-day-old eggs of this insect. Extracts of Vernonia holosenicea, Lychnophora ramosissima and Chromolaena chaseae had higher impact on S. frugiperda, while those of Eremanthus elaeagnus and L. ericoides were more selective to T. pretiosum and T. remus. Asteraceae extracts present potential for integrated pest management programs of S. frugiperda.  相似文献   

3.
The grape vine moth, Lobesia botrana (Denis and Schiffermüller) (Lepidoptera: Tortricidae), attacks vineyards mostly in Southern Europe and Northern Africa. The efficiency of most control methods depends on the treatment of pest populations at their most susceptible stages, therefore the prediction of the moth’s development cycle would help greatly in determining an optimal treatment schedule. One strategy for protecting against this pest is based on the day of maximum flight of males per generation (peak flight), when the mating between males and females and the laying of eggs reaches its maximum. The knowledge of these times would enable us to decide the kind of insecticide and the best time to target it. The time of maximum flight can be predicted by the Touzeau model of accumulated average daily temperature exceeding the development threshold. As shown, the fit of this model on data from the Ribera del Duero region in Spain is not accurate enough. Therefore, we propose an empirical and biologically plausible model based on logistic transformation of daily temperatures, which proves a better fit and permits simple inclusion of additional variables such as relative humidity.  相似文献   

4.
分别用番茄果实、辣椒果实和人工饲料饲养斜纹夜蛾,观察不同食料对斜纹夜蛾(Spodoptera litura Fabricius)的生长发育、存活、不同龄期幼虫的粪便重量、成虫产卵量的影响,组建相应食料下的斜纹夜蛾实验种群生命表.结果表明:喂饲辣椒果实的斜纹夜蛾幼虫发育历期和全世代显著长于喂饲番茄和人工饲料,喂饲人工饲料的斜纹夜蛾不同龄期幼虫的粪便重量显著重于喂饲辣椒果实;种群趋势指数(Ⅰ)均大于1, 内禀增长力(rm)均大于0,斜纹夜蛾种群呈增长趋势.  相似文献   

5.
Ulla B?ng 《Potato Research》2007,50(2):185-203
The potential utility of natural volatiles in various essential oils (EOs) from plants as fumigants to control potato tuber (Solanum tuberosum L.) pathogens was assessed. The antifungal effects of the volatiles at various concentrations were studied at 10 °C both in vitro using conidial suspensions of Helminthosporium solani, Fusarium solani var. coeruleum and Phoma foveata plated on agar, and in vivo by inoculating potato tubers. The effects of the volatiles on the mycelial growth of Rhizoctonia solani were also studied, but only in vitro. Vapours of many of the EOs tested exhibited some fungicidal activity but volatiles of garlic, Allium sativum, were, with few exceptions, most effective on all four pathogens in all experiments. An exposure time of at least 2 weeks was usually required for good control of disease development in vivo. Vapours of A. sativum never stimulated conidial germination, as was observed with some other oils, or damaged tubers, but those of Armoracia rusticana caused tuber collapse. Volatiles from thyme (Thymus vulgaris) EO showed antifungal activity in vitro on all four pathogens, but did not control F. solani, P. foveata or H. solani in vivo. In contrast, sage (Salvia officinalis) EO was ineffective against P. foveata and H. solani in the in vitro system, but controlled disease development in vivo at similar doses. The sometimes conflicting results obtained in the two test systems show that screening in vitro only is insufficient for evaluation of potent antifungal substances to be used in practice.  相似文献   

6.
Powders prepared from sweetflag Acorus calamus rhizomes collected at both high (1700 m) and low (900 m) altitude in Eastern Nepal were admixed with wheat at concentrations in the range 0.05–2% w/w and the wheat infested with Sitophilus oryzae or S. granarius adults. Following a 7 day incubation, the mortality of both species was significantly lower at 20 °C than at 30 °C, and the material collected from high altitude was slightly less toxic than that from low altitude. The moisture content of the wheat (14 or 17%) and the part of the rhizome used to prepare the powder (young or mature growth) had no apparent effect on the toxicity of the preparation. Sitophilus granarius (L.) adults were more tolerant of the material than S. oryzae (L.), while the converse was true for larvae developing in treated grain. An admixture rate of approximately 2% w/w admixed rhizome powder was required to give complete kill of adults of both species following 7 days exposure at 20 °C, while a concentration of 1% w/w either prevented the emergence of adults or killed them rapidly following emergence when wheat containing eggs of either species was incubated for 7–8 weeks at 30 °C.

The β-asarone content of the rhizome powders was determined by GC-MS as 6.4 and 4.7% w/w (mature section of rhizomes collected at high and low altitudes, respectively) and 3.6 and 4.0% w/w (young sections of rhizomes collected at high and low altitudes, respectively). It is anticipated that, under field conditions and in the temperature range 20–30 °C, the initial residue of approximately 1300 mg/kg β-asarone required to disinfest wheat containing these weevil species would decline rapidly due to evaporation.  相似文献   


7.
将融合基因mCry1AbWp3A构建原核表达载体pET30A-mCry1AbVip3A,转入大肠杆菌BL21(DE3),通过优化诱导条件获得mCry1AbVip3A蛋白.室内生测mCry1AbVip3A蛋白对亚洲玉米螟和草地贪夜蛾的杀虫效果,发现饲喂终浓度为128.44 ng/mL的mCry1AbVip3A蛋白的亚洲玉...  相似文献   

8.
The potential of using near-infrared reflectance spectroscopy (NIRS) to discriminate between seven broadleaf weed species, sunflower and wheat stubble was evaluated. Our results showed that the spectral window between 750 and 950 nm, which corresponds to near-infrared wavelength, was able to discriminate among wheat stubble, sunflower and the most problematic “hard-to-control” weeds in no-till sunflower, i.e. Little mallow (Malva parviflora L.) and Ecballium elaterium L. These results are promising for further work in real-time remote sensing identification of weed patches in sunflower fields.  相似文献   

9.
Of the 128 wild rices screened, 83 accessions were resistant to the brown planthopper Nilaparvata lugens (Stål). Resistant accessions were non-preferred and significantly more individuals settled on susceptible TN1 plants than on resistant ones. The quantity of food ingested and assimilated by N. lugens on resistant accessions was less than on susceptible TN1. N. lugens caged on resistant accessions had slow nymphal development, reduced longevity and low fecundity. Two wild rice species, Oryza officinalis and O. punctata, reduced the percentage hatchability of N. lugens eggs. A significant reduction in population growth was observed on resistant accessions compared with susceptible TN1.  相似文献   

10.
Crenate broomrape (Orobanche crenata Forks.) is a major constraint for grain and forage legume cultivation in Mediterranean agriculture, to which little resistance is available. We studied the response to O. crenata of a germplasm collection of chickling pea (Lathyrus cicera L.) in field trials over two seasons showing that resistance although scarce and masked by confounding factors, is available and can be used in breeding. The level of infection was highly influenced by environmental factors and plant growth cycle. Earlier accessions were less infected due to competition of the earlier settled pods with O. crenata tubercles. O. crenata infection strongly reduced host biomass and grain yield. Deviations from the polynomic regression gave an improved approximation of the true genetic resistance levels present in the germplasm.  相似文献   

11.
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   

12.
The inheritance of resistance to the green leafhopper, Nephotettix virescens (Distant) (Homoptera: Cicadellidae), in 12 cultivars of rice (Oryza sativa L.) was studied at Joydebpur, Bangladesh. The resistance of Kosatawee is governed by a single recessive gene. The remaining 11 varieties possess single dominant genes for resistance, which are different from the genes Glh 1, Glh 2, Glh 3 and Glh 5. The single dominant genes conveying resistance in TAPL 796, Ptb 18 and IR36 are allelic to each other but are non-allelic to the dominant resistance gene of Maddai Karuppan. The resistance genes in TAPL 796 and Maddai Karuppan were designated Glh 6 and Glh 7 respectively. The dominant resistance gene in Sulai is independent of Glh 6, but its allelic relationship to Glh 7 is not known. The allelic relationships of the dominant genes for resistance of Sulai, TAPL 628, TAPL 651, Leu-Wei-Theu, Bir-co-se-mao-17, Gu-win-gu-gi-goo, and Dikwee to Glh 6 and Glh 7 need to be investigated.  相似文献   

13.
The phytotoxicity and sensitivity of succeeding crops to the new sulfonylurea, sulfosulfuron, have been reported although there is insufficient data on the phytotoxic effect of field soil residues. Growth chamber bioassays were conducted to detect the presence of residues in soil samples previously treated with sulfosulfuron at the recommended rate and double rate (20 and 40 g a.i./ha) that could affect the succeeding crop. Soil samples were collected between 7 and 9 months after sulfosulfuron application in field selectivity assays at nine different locations in Northern and Central Spain. The bioassay test species were barley (Hordeum vulgare L.) ‘Graphic’, sunflower (Helianthus annuus L.) ‘Albasol’ and common vetch (Vicia sativa L.) ‘Neska’, typical crops grown in rotation with wheat (Triticum aestivum L.) in this area. Sulfosulfuron residues did not affect barley and common vetch, but inhibited shoot length, root length and root dry weight of sunflower seeded into some soils treated with the 2× rate (40 g a.i/ha) 9 months earlier.  相似文献   

14.
根据已构建苦瓜果实均一化文库中获得的1个与SAMDC基因相关的EST序列,采用3′RACE技术,克隆获得1个苦瓜SAMDC基因的cDNA全长序列,命名为McSAMDC(GenBank登录号为KC632099).生物信息分析结果表明,该cDNA全长l900bp,5′UTR和3′UTR分别长501、325bp.该cDNA序列存在3个开放读码框(微型tORF、上游读码框uORF和主读码框mORF),其中mORF长1077bp,编码358个氨基酸,预测分子量为39.31ku,含有酶原剪切位点结构域和蛋白快速降解有关的PEST二个保守结构域.二级结构分析显示,McSAMDC含有无规卷曲(45.53%)、α-螺旋(29.33%)、伸展链(19.83%)、β-转角(5.31%).序列分析结果表明,McSAMDC与拟南芥(CAA69073.1)、琴叶拟南芥(XP002882231.1)和雪里红(AAS45435.1)的氨基酸序列相似性分别达到69%、68%和68%.亚细胞定位结果表明,McSAMDC定位在细胞质中.荧光定量结果表明,McSAMDC在果实膨大期表达量最高,并随之迅速下降,并从成熟初期至完全成熟期该基因表达量逐渐增大.  相似文献   

15.
During 2002–2006, nymph bands of Locusta migratoria manilensis (Meyen) were treated by ground and aerial applications in 6000 ha of grasslands and the nearby beach of Yellow river using a soybean oil miscible suspension ULV formulation of Metarhizium anisopliae var. acridum isolate CQMa102. The formulation was also applied in Tianjin, Henan, Hebei, Shandong and Shanxi provinces of Northern China by ground and aerial applications. During field studies, cage tests were carried out in corresponding field plots in order to estimate the mortality accurately. Doses of 3.3×1012 and 5.0×1012 conidia ha−1 were equally effective and caused 90% mortality 9–13 days after treatment. In the ground spray trial, 3.3×1012 conidia ha−1 killed >90% of L. migratoria manilensis 11–15 days after treatment in a wide variety of vegetation and weather conditions. The decline of locust populations was slower where vegetation was taller and denser. In the aerial spray treatment, the final percent survival of locusts was lowered to 10% at 11 and 14 days in the field cage and open field locusts, respectively. Furthermore, the M. anisopliae oil miscible suspension formulation did not appear to harm natural enemies of locusts in the field.  相似文献   

16.
Field strains of Botryotinia fuckeliana were isolated from diseased grape berries which were collected at the harvest, between 1993 and 1997, from French vineyards located in Alsace, Armagnac, Bordeaux, Champagne and Loire Valley. According to the inhibitory effects of fungicides towards spore germination, germ-tube elongation and mycelial growth, several phenotypes could be characterized. Thus, two types of benzimidazole (e.g. carbendazim, thiabendazole)-resistant strains were detected; negative cross-resistance towards diethofencarb, diphenylamine and dicloran was found only in one type. Most dicarboximide (e.g. iprodione, procymidone, vinclozolin)-resistant strains were also weakly resistant to aromatic hydrocarbon fungicides (e.g. chloroneb, dicloran, tolclofos-methyl) but remained sensitive to phenylpyrroles (e.g. fenpiclonil, fludioxonil). However, in some other dicarboximide-resistant strains, resistance was observed either as being restricted to dicarboximides or as extending weakly to phenylpyrroles. Towards anilinopyrimidines (e.g. cyprodinil, mepanipyrim, pyrimethanil), three resistant phenotypes have been identified. In the most resistant one, resistance was restricted to anilinopyrimidines, whereas in the others, resistance extended to various other groups of fungicides including dicarboximides, phenylpyrroles, sterol biosynthesis inhibitors (e.g. tolfanate, prochloraz, tebuconazole) and the hydroxyanilide derivative, fenhexamid. According to the pattern of cross-resistance, two phenotypes were characterized within these multifungicide-resistant strains. In vitro tests conducted with fenpropimorph, fenpropidin and spiroxamine, revealed the existence of strains highly susceptible to these sterol Δ14- reduction inhibitors. This property was correlated with a decreased sensitivity towards fenhexamid.  相似文献   

17.
Chestnut (Castanea sativa) shell and eucalyptus (Eucalyptus globulus) bark, waste products of the food and wood industries, respectively, were analysed as potential sources of antioxidant compounds. The extraction yield, the antioxidant activity and total phenols content of the extracts were greater in chestnut shell than in eucalyptus bark for most of the extraction conditions essayed. Extraction of chestnut shell with a 2.5% Na2SO3 aqueous solution led to the highest extraction yield, 25.6%, total phenols, 13.4 g gallic acid equivalent/100 g oven-dried shell, and FRAP antioxidant activity, 80.7 mmol ascorbic acid equivalent/100 g oven-dried shell. Extraction with methanol:water (50:50, v/v) provided the best results for eucalyptus bark. The antioxidant activity and the total phenols content of the extracts had a positive linear correlation. FTIR spectroscopy confirmed the higher content of phenolic compounds in chestnut shell extracts compared to eucalyptus bark extracts. Chestnut shell extracts were characterized by the presence of high molecular weight species whereas lower molecular weight species were predominant in eucalyptus bark extracts.  相似文献   

18.
This paper reviews the importance of Potato apical leaf curl virus (PALCV) in India, the biology of its major vector Bemisia tabaci and possible control measures of PALCV and B. tabaci. PALCV has appeared as a new problem in potato growing areas of northwestern plains of India. The first report of PALCV was made from Hissar around 2000. PALCV is a whitefly (B. tabaci) transmitted viral disease and the symptoms are manifested primarily in the form of upward or downward curling of leaves, with 40–75% infection being recorded in cultivars grown in the Indo-Gangetic Plains of India. B. tabaci is a polyphagous pest that feeds on numerous fibre (particularly cotton), food, vegetable and ornamental plants. B. tabaci produces many generations in a year and reaches high population densities. To check the disease incidence, whitefly suppression using imidacloprid either as seed treatment or as foliar application early in the season is recommended. To minimize within-field spread of viruses, removal of virus-infected plants is suggested. Application of mineral and vegetable oils has been found to inhibit virus transmission and possibly can help to avoid difficulties with insecticide resistance in whiteflies.  相似文献   

19.
为了筛选抗禾谷孢囊线虫(Heterodera avenae)的小麦资源,以禾谷孢囊线虫保定群体为试虫,采用室内接种方法测试了41份来自CIMMYT的小麦品种(系)的抗病性;分别采用室内接种法和田间病圃法测试了27份国内冬小麦品种和1份饲用小麦品种的抗病性。结果表明,在41份CIMMYT小麦品种(系)中,2个属高抗,7个属中抗,其他均属感病。所有参试的国内小麦品种在室内和田间测定中均表现为高感。比较三种不同小麦品种抗孢囊线虫鉴定方法,室内接种鉴定比田间病圃鉴定发病严重,且简便易行,鉴定结果更可靠。  相似文献   

20.
非生物胁迫对小麦的生长发育具有不良影响,克隆与非生物胁迫相关的基因,并对其结构及表达特性进行分析,可以为进一步探索小麦的抗逆机制和抗逆育种奠定基础。本研究利用同源克隆技术从普通小麦品种中国春中克隆了水稻E3泛素连接酶基因OsHTAS的同源基因TaHTAS-5A(GeneBank登录号:MF967573),并利用生物信息学方法对其基因序列特征进行分析;利用qRT-PCR技术对该基因在小麦不同组织及不同逆境胁迫下的表达模式进行分析;同时,对该基因的表达产物进行了亚细胞定位。结果表明,小麦TaHTAS-5A基因含有220bp的5′UTR、1 242bp的ORF以及126bp的3′UTR,共编码413个氨基酸;基因组分析表明,该基因全长3 819bp,共包含4个外显子和3个内含子;缺体-四体定位表明该基因位于小麦5A染色体上;蛋白结构分析显示,TaHTAS-5A蛋白的N端包含四个跨膜结构域,C端包含一个E3泛素连接酶特有的RING finger保守结构域,具有植物E3泛素连接酶的结构特征;qRT-PCR结果显示,TaHTAS-5A对高温、低温和ABA都有响应,对干旱和盐响应不敏感;TaHTAS-5A在小麦的根、茎、叶和幼穗等不同组织中均有表达,但表达量有差异,在叶和穗中的表达量明显高于根部和茎部;亚细胞定位结果表明,TaHTAS-5A位于细胞膜上。本研究为进一步探究小麦TaHTAS-5A基因的功能奠定了基础,也为小麦非生物胁迫抗性改良提供了一定的理论依据。  相似文献   

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