印楝油对作物病虫害的生物活性研究概况

印楝油对农作物害虫具有防治作用,而且具有抗菌、抗病毒的能力,还可用于线虫的防治。所以印楝油应用于杀虫剂、杀菌剂等植物源生物农药的制备。本文对印楝油在作物病虫害防治上的研究及应用做了介绍。     

印楝素在不同溶剂中的稳定性

用高效液相色谱法定量检测了印楝素在不同溶剂中的降解率。用印楝甲醇抽提物和印楝素纯品试验的结果表明:印楝素在甲醇、乙腈、乙醇和N,N-二甲基甲酰胺(DMF)中具有不同的稳定性,印楝素在这4种溶剂中的降解速度顺序为乙醇>甲醇>DMF>乙腈。用这4种溶剂溶解并在(54 )癈保存14d后,印楝甲醇抽提物中的印楝素分别降解 45.3%、38.7%、27.5%、22.3%;印楝素纯品分别降解 62.6%、41.9%、28.0%、11.1%。在(0 )癈保存14d后这4种溶剂中的印楝素都基本不降解,在室温下保存14d后都只有少量降解。从各方面考虑,DMF是一种适合于加工印楝素制剂的溶剂。     

植物源杀虫剂印楝素研究开发及应用进展

印楝素作为一种性能优良、最具有开发价值的植物源杀虫剂,越来越受人们的重视。综合印楝素的国内外研究进展,对印楝素的提取分离、有效成分鉴定、分析方法、稳定性、作用机制、安全性、剂型开发应用等方面进行了系统的综述,阐明了印楝素开发中存在的问题,并对印楝素今后的应用发展进行了展望。     

国外农药信息集锦

正Terramera创新生物农药RANGO获美环保署登记借助印楝油高效防治多种病虫害Terramera的创新广谱农药RANGO?近日获得了美国环保署的登记,产品可用于防治螨虫和害虫,包括蚜虫、牧草虫、蠕虫、粉虱,以及真菌病害,例如灰霉病、镰刀菌和白粉病。RANGO?的有效成分为冷压提取的印楝油(70%)。RANGO?这款含有植物源活性成分的专利制剂具有出色的混合和操作特性。产品可高效防治     

印楝素类成分对照品的制备与鉴定

[目的]报道一种快速、高效制备印楝素类成分对照品的方法。[方法]采用反相制备高效液相色谱(RP-PHPLC),从印楝粗提物中分离得到10种化合物,并采用NMR和HPLC Q-TOF MS对分离产物进行结构鉴定,通过HPLC检测,外标法或面积归一化法定量。[结果]10种化合物分别是印楝素A(azadirachtin A,AZ-A)、印楝素B(azadirachtin B,AZ-B)、印楝素D(azadirachtin D,AZ-D)、印楝素H(azadirachtin H,AZ-H)、印楝素I(azadirachtin I,AZ-I)以及nimbin、salannin等,10种印楝素类成分对照品的纯度均98%。[结论]该方法操作简便,可重复进样,适用于制备高纯度印楝素类成分对照品;该对照品可用作印楝素相关产品、制剂质量控制及农产品农药残留检测等实践中的定性、定量依据。     

印楝素与三唑磷混用防治三化螟和稻纵卷叶螟的田间药效

田间试验结果表明,印楝素与三唑磷混用对水稻三化螟和稻纵卷叶螟有良好的防治效果,每667m2用印楝素与三唑磷混剂100mL(20%三唑磷乳油66.7mL+0.3%印楝素乳油33.3mL)对三化螟的平均防效达83.6%,对稻纵卷叶螟的平均防效达92.1%,且对水稻安全无药害。     

O.3%印楝素乳油的高效液相色谱分析

由华南农业大学昆虫毒理研究室研制并已获得我国农药登记的0.3%印楝素乳油是一种高效、低毒的植物性杀虫剂,对小菜蛾、稻飞虱等害虫具有显著的拒食和生长发育抑制作用.目前,国内关于印楝素制剂的分析方法未见报道.     

0．3％印楝素乳油的高效液相色谱分析

由华南农业大学昆虫毒理研究室研制并已获得我国农药登记的0．3％印楝素乳油是一种高效、低毒的植物性杀虫剂，对小菜蛾、稻飞虱等害虫具有显著的拒食和生长发育抑制作用。目前，国内关于印楝素制剂的分析方法未见报道。     

印楝素定量技术研究进展

印楝素是一种极具开发前景的植物源生物农药。在对印楝素在各种样品和环境中的残留情况以及商品制剂生产中，要求有一种简便、快速、灵敏的检测方法。本文就近年来对印楝素的含量分析研究中的几种重要技术做了介绍，如：RP-HPLC、SFC、HPLC-APCI-MS、ELISA、比色法。     

印楝树种核抽提物对伊蚊幼虫的防治

自从 Chopra(1928)首先报道印楝树(Azadirachta indica)产品的杀虫性质后,主要在印度开始研究其忌避作用。继而发现印楝产品具有抑制昆虫生长发育的作用,自此在世界范围内广泛开展了对印楝的研究。印楝种核的水或醇的粗抽提物可使半变态或全变态昆虫发生异常变态并降低繁殖力,其叶片抽提物也有同样效果但程度较差。     

加强水稻主要病虫科学用药防控的原则和措施

水稻是我国种植面积最大的作物,也是我国病虫害防治用药量最多的作物.针对近几年水稻主要病虫害频繁发生的严重态势,分析了水稻病虫害发生危害新特点及频繁暴发的原因,提出了水稻主要病虫害科学用药防控的基本原则和防治措施.     

试论拟除虫菊酯类杀虫剂在水稻田中的应用

拟除虫菊酯杀虫剂具有高效、安全、广谱及对人畜低毒等特点,在农业上得以广泛应用,已成为杀虫剂市场的支柱之一。但由于其对鱼毒性高,我国禁止其在水稻田使用。随着我国高毒农药的禁用以及水稻害虫对常用药剂抗性的发展,水稻田用药将出现“缺口”。本文介绍了日本、菲律宾和越南等国家应用拟除虫菊酯杀虫剂防治水稻害虫的情况,推荐了一些稻田防虫的拟除虫菊酯品种,并提出了在我国拟除虫菊酯杀虫剂用于水稻田的几点建议。     

硅肥在水稻超高产栽培中的作用及其施用技术

阐述了硅营养在水稻超高产栽培技术体系中的重要作用,介绍了2009年烟台众德集团水稻施硅肥促根、壮秆、抗倒,强化对病虫害的抵抗力,提高水稻同化CO2的能力,提高水稻产量和品质的试验结果,倡导实施以增加硅肥营养为主导的科学施肥,预防超高产水稻倒伏的问题。     

Cytokinin Confers Brown Planthopper Resistance by Elevating Jasmonic Acid Pathway in Rice

Plants have evolved a sophisticated defense system that employs various hormone pathways to defend against attacks by insect pests. Cytokinin (CK) plays an important role in plant growth and stress tolerance, but the role of CKs in plant–insect interaction remains largely unclear. Here, we report that CKs act as a positive regulator in rice resistance against brown planthopper (BPH), a devastating insect pest of rice. We found that BPH feeding promotes CK biosynthesis and signaling in rice. Exogenous application of CKs significantly increased the rice resistance to BPH. Increasing endogenous CKs by knocking out cytokinin oxidase/dehydrogenase (OsCKXs) led to enhanced resistance to BPH. Moreover, the levels of the plant hormone jasmonic acid (JA) and the expression of JA-responsive genes were elevated by CK treatment and in OsCKXs knockout plants. Furthermore, JA-deficient mutant og1 was more susceptible to BPH, and CK-induced BPH resistance was suppressed in og1. These results indicate that CK-mediated BPH resistance is JA-dependent. Our findings provide the direct evidence for the novel role of CK in promoting insect resistance, and demonstrate that CK-induced insect resistance is JA-dependent. These results provide important guidance for effective pest management strategies in the future.     

多虫克防治水稻害虫田间药效试验

试验结果表明，多虫克对稻纵卷叶螟、褐飞虱、三化螟具有较好的防治效果，是水稻害虫总体防治的理想药剂。9％多虫克乳油50ml／667m^2对稻纵卷叶螟的防治效果达95．1％，与甲胺磷相当；对褐飞虱的防治效果达93％以上，持效期长达40d，与噻嗪酮、吡虫啉相当。9％多虫克乳油100ml／667m^2对三化螟的防治效果达90．9％，与高效氯氟氰菊酯相当，比甲胺磷提高18．4％。     

汉中水稻田高产栽培技术与农肥施用概况调查研究

通过调查研究汉中地区水稻田高产栽培技术、农肥施用概况以及常见病虫害防治方法,可以指导农民正确施肥,合理种植,提高水稻产品收入.同时也为治理汉中地区水稻田面源污染问题提供基础参考资料,以达到保护环境的目标,实现人与环境的和谐发展.最后提出减少水稻田面源污染的治理措施.     

防治水稻害虫的杀虫剂及剂型

介绍了国内防治水稻害虫的主要杀虫剂品种以及剂型的应用效果,同时指出选用药剂时不仅要考虑作用靶标、防效、抗药性和成本,而且还应考虑到剂型的安全环保性,以及药剂在水稻叶面上的沾湿和铺展能力,必要时可以添加有机硅助剂来提高水稻杀虫剂的药效。     

Overexpression of an Osa-miR162a Derivative in Rice Confers Cross-Kingdom RNA Interference-Mediated Brown Planthopper Resistance without Perturbing Host Development

Rice is a main food crop for more than half of the global population. The brown planthopper (BPH, Nilaparvata lugens) is one of the most destructive insect pests of rice. Currently, repeated overuse of chemical insecticides represents a common practice in agriculture for BPH control, which can induce insect tolerance and provoke environmental concerns. This situation calls for innovative and widely applicable strategies for rice protection against BPH. Here we report that the rice osa-miR162a can mediate cross-kingdom RNA interference (RNAi) by targeting the NlTOR (Target of rapamycin) gene of BPH that regulates the reproduction process. Through artificial diet or injection, osa-miR162a mimics repressed the NlTOR expression and impaired the oviposition of BPH adults. Consistently, overproduced osa-miR162a in transgenic rice plants compromised the fecundity of BPH adults fed with these plants, but meanwhile perturbed root and grain development. To circumvent this issue, we generated osa-miR162a-m1, a sequence-optimized osa-miR162a, by decreasing base complementarity to rice endogenous target genes while increasing base complementarity to NlTOR. Transgenic overexpression of osa-miR162a-m1 conferred rice resistance to BPH without detectable developmental penalty. This work reveals the first cross-kingdom RNAi mechanism in rice-BPH interactions and inspires a potentially useful approach for improving rice resistance to BPH. We also introduce an effective strategy to uncouple unwanted host developmental perturbation from desirable cross-kingdom RNAi benefits for overexpressed plant miRNAs.     

Neem--an omnipotent plant: a retrospection

Neem (Azadirachta indica A. Juss.) has universally been accepted as a wonder tree because of its diverse utility. Multidirectional therapeutic uses of neem have been known in India since the Vedic times. Besides its therapeutic efficacies, neem has already established its potential as a source of naturally occurring insecticide, pesticide and agrochemicals. Safe and economically cheaper uses of different parts of neem in the treatment of various diseases and in agriculture are discussed in this article. It further deals with the active chemical constituents of various neem formulations. Commercially available neem products are also mentioned along with their respective applications. Furthermore, evaluation of safety aspects of different parts of neem and neem compounds along with commercial formulations are also taken into consideration. Systematic scientific knowledge on neem reported so far is thus very useful for the wider interests of the world community.     

浅议吡虫啉的剂型

吡虫啉是一种低毒、高效、机理独特的新型杀虫剂,尤其对有机磷、拟除虫菊酯、氨基甲酸酯类已产生抗药性的害虫防治效果更佳。近年来,开发吡虫啉杀虫剂的剂型也已成为研究的热点。论述了吡虫啉农药特性和主要剂型,以及较详细地讨论了剂型开发和进展情况。