Study on Cytoplasmic polyhedrosis virus on Dendrolimus superans

Cytoplasmicpolyhedrosisvirus(CPV)ofEendrolimussuperans(DsCPV)isone.oftheimportantpatholo-gensofthelarvaeOfDendFOHffiussuPerans.InoFdertoutiIizeDsCPVincontrol,themorphoIogy,toxicity,infeCtionanddestroyingprocedureinthemidgutofinsectofDsCPVwereStudied.ThecontrolofDen-dIOhffiussuPeranswiththisvirusinasmaIIareainforestwascarriedout.ResearchmethodMorphologyobservationScanningeIectronmicroscopeandtransmissioneIeCtronmicroscopewereusedtoobservethemor-phoIogy.ToxicityteStingThesameamo…     

Relationship between root-endophytic microbial communities and replant disease in specialized apple growing areas in Europe

Apple replant disorders are one of the causes of the downward trend of land planted with apple orchards in Central Europe. A specific transnational survey was thus conducted on apple root associated microorganisms, aimed at increasing the knowledge regarding crop management to counteract this tendency. Soil health was evaluated using a bioassay test with root cuttings of the clonal M9 rootstock, one of the most commonly used rootstocks in Europe. Plant growth response in replant, fallow and gamma ray-sterilized soil was evaluated using soil samples taken from nine orchards selected (three per country) from specialized apple growing areas of Germany, Austria and Italy. Plant growth significantly differed between treatments but not between countries. Root endophytic fungi were confirmed as one of the main components of growth reduction, while endophytic nematodes (Pratylenchus sp.) were not. The large set of quantitative and qualitative data of root endophytic fungi allowed to clarify that Cylindrocarpon-like fungi (Ilyonectria spp. and Thelonectria sp.) had a major pathogenic role in the three countries, while Pythium spp. prevailed as pathogen only in German orchards. Gamma ray-sterilized soil resulted in a more-than-proportional increase of plant growth (42% and 31% respectively vs. replant and fallow) as compared to that observed between fallow and replant soil (18%). This best performance in gamma ray-sterilized soil, in addition to the lowest root colonization by Cylindrocarpon-like fungi in this treatment, appeared to be due to the different composition of fungal communities as compared to two other treatments (fallow and replant soil), which instead were highly similar to each other. This difference was due to a shift of community composition toward Fusarium and binucleate Rhizoctonia, which prevailed in sterilized soil.     

黑杨萎蔫叶片萃取物对蛾类成虫诱集活性的研究

采用水蒸气蒸馏和二氯甲烷萃取，提取黑杨萎蔫叶片中的挥发性诱虫活性物质。田间生物活性测定结果表明，萃取液对小地老虎、甜菜夜蛾、灰双纹螟成虫具有较高的诱集活性，且诱集活性随萃取液剂量的增大而提高，诱蛾种类和数量随时间、地点不同而变化，诱集到的蛾类以雌性为主。     

蚧侧链孢对黑刺粉虱致病力的研究

生物测定证实,蚧侧链抱(Pleurodesmospora coccorum)对茶黑刺粉虱(Aleurocanthus spiniferus)和柑桔粉虱(Dialeurodes citri)具较强致病力。田间调查表明,该虫生真菌在黑刺粉虱种群中有流行潜能。在14.0～15.1℃和92～93%RH下,对黑刺粉虱越冬代蛹的LC_(50)=1.2×10~8孢子/ml。LT_(50)随菌剂中孢子浓度的增大而减小,中等剂量(1.0×10~8孢子/ml)的LT_(50)=14.85日。处理间致死率差异达极显著水平。     

Assessment of allelopathic potential of barnyard grass (Echinochloa crus-galli) on rice (Oryza sativa L.) cultivars

Laboratory, greenhouse and field studies were conducted to assess the allelopathic potential of 44 rice cultivars (Oryza sativa L.) on barnyard grass (Echinochloa crus-galli P. Beauv. var. oryzicola Ohwi). Rice cultivars exhibited marked differences in the inhibition of barnyard grass growth and development. In the laboratory, Gin shun rice cultivar extracts exhibited the greatest activity on the weed seedling growth, reducing dry weight by 61%, while Kasarwala mundara cultivar extracts exhibited the greatest activity on seed germination, reducing germination by 23% and germination speed by 46%. In a greenhouse study of a residue mixture, the Philippine 2 cultivar showed the greatest inhibition percentage on seedling emergence (57%), total seedling length (74%) and dry weight (73%). In the field study, the Juma 10 cultivar demonstrated the most inhibitory effect by reducing barnyard grass tiller number (80%), leaf area (49%) and leaf (61%) and stem (74%) dry weight (68%). These results suggest that there are differences among the varieties for allelopathic inhibition of barnyard grass, and that the development of barnyard grass suppressive rice cultivars that have greater allelopathic potential may be possible.     

诃子抗氧化活性物质提取工艺与抗氧化活性研究

对诃子抗氧化活性物质提取工艺、抗氧化活性及其初步物质基础进行了研究。结果表明,最佳提取工艺为：乙醇体积分数50%、液料比20、提取温度60℃、提取次数4次、提取时间7min;总还原力、FRAP法抗氧化能力和DPPH自由基清除能力的结果均显示诃子粗提物具有很强的抗氧化活性。生物活性追踪结果发现,诃子抗氧化活性物质主要由存在于乙酸乙酯相的弱极性化合物组成,该相质量浓度为25、50μg/mL样品的总还原力OD700值分别为0.197±0.002和0.380±0.006,FRAP法抗氧化能力OD593分别为0.272±0.023和0.631±0.002,DPPH自由基清除率分别为(86.838±0.600)%和(90.318±0.917)%。相关关系表明,诃子抗氧化活性的主要物质基础为总黄酮和总多酚。     

SfaMNPV-D克隆株感染小菜蛾的生物测定

芹菜夜蛾核型多角体病毒-D克隆株感染2龄和3龄小菜蛾幼虫,测得LC50分别为2.01×105和2.82×107PIBs/lml,相同浓度的病毒感染小菜蛾,致死率与幼虫虫龄呈负相关。     

山西省虫生真菌资源应用初步评价

为了虫生真菌资源进一步应用到害虫防治上,本文选取山西省虫生真菌优势类群中的绿僵菌(Metarhizium)、白僵菌(Beauveria)、拟青霉(Paecilemyces)、轮枝菌(Verticillium)、曲霉菌(Aspergillus)和青霉菌(Penicillium)6个属中9种致病虫生真菌,运用喷雾法和涂抹法进行生物学测定,并对其在害虫生物防治的应用前景进行了评价。结果表明,绿僵菌和轮枝菌具有良好的高效低毒特点,可以考虑作为生防制剂的备选菌株进行田间防效试验。     

4种硼酸盐对台湾乳白蚁的毒效研究

[目的]了解4种硼酸盐饵剂对台湾乳白蚁工蚁的毒效。[方法]采用选择性取食方法,在室内测定4%硼酸饵剂、4%硼砂饵剂、4%偏硼酸钠饵剂和4%硼酸钠饵剂致死台湾乳白蚁工蚁的效果。[结果]除对照药物灭蚁灵能在9 d内致死全部的供试白蚁外,4种硼酸盐饵剂致死全部供试白蚁需20~24 d的时间。其中,4%硼酸饵剂对白蚁的致死速度最快,可在20 d内致死所有的供试白蚁;4%偏硼酸钠饵剂对白蚁的致死速度最慢,致死所有供试个体需24 d的时间;4%硼砂饵剂和4%硼酸钠饵剂致死全部白蚁所需的时间均为23 d。[结论]4种硼酸盐饵剂对台湾乳白蚁均具有较好的毒杀效果,值得在白蚁防治的实际工作中试验应用。     

Effects of alfalfa leaf extracts and phenolic allelochemicals on early seedling growth and root morphology of alfalfa and barnyard grass

Alfalfa (Medicago sativa L.) plants contain water-soluble substances that are autotoxic as well as allelopathic to other plants. Laboratory experimentation through a petri dish assay with imbibed seeds was conducted to evaluate the phytotoxic effects of alfalfa cv. “Vernal” leaf extracts, coumarin, trans-cinnamic acid, o-coumaric acid, and hydro-cinnamic acid on the seedling growth and anatomical responses of 6 day-old alfalfa and barnyard grass. With increasing concentration, the alfalfa leaf extracts significantly reduced root lengths of alfalfa and barnyard grass (Echinochloa crus-galli, Beauv. var. oryzicola Ohwi). Coumarin, trans-cinnamic acid, o-coumaric acid, and hydro-cinnamic acid at 10⁻⁴ M significantly reduced root lengths of alfalfa and barnyard grass. The root systems, especially root tips of alfalfa, were stunted and swollen by the aqueous alfalfa leaf extracts at 30 g l⁻¹ and coumarin at 10⁻³ M. This research suggests that alfalfa plant extracts significantly affected root growth and morphological differentiation of susceptible plants, resulting in reduction of their biomass in the presence of either autotoxic or allelopathic compounds. The results may have value in enabling weed control based on natural plant extracts.