10种中草药提取物对棉铃虫、绿盲蝽触杀活性研究

棉铃虫Helicoverpa armigera和绿盲蝽Apolygus lucorum是两种重要的经济作物害虫。为寻找一种安全高效的防治新手段,本文对10种中草药提取物触杀活性开展了研究。结果表明,在10种中草药提取物中,苦杏仁杀虫活性最高,药后7 d棉铃虫、绿盲蝽校正死亡率分别为65.4%和100%。发现苦杏仁粗提物经不同溶剂萃取后发现,氯仿萃取时析出物对绿盲蝽触杀活性最高,药后7 d校正死亡率可达96.9%。硅胶柱分离结果表明,流分L36-48具有较高的触杀活性,药后7 d校正死亡率为84.7%。本研究评价了10种中草药提取物对棉铃虫和绿盲蝽的触杀活性,并对苦杏仁有效成分开展了初步的分离鉴定,以期为两种害虫高效安全的新型药剂开发提供理论基础。     

转Bt基因作物对植物—害虫—天敌食物链的影响

种植转Bt基因作物已经成为当前及未来农业的发展趋势。转Bt基因作物可以有效控制棉铃虫（〖WTBX〗Helicoverpa armigera〖WTBZ〗）、玉米螟（〖WTBX〗Ostrinia furnacalis〖WTBZ〗）等多种靶标害虫。但研究表明Bt作物的种植会改变害虫演化地位,并且Bt毒素可能沿着食物链传递,而对天敌构成潜在的威胁。基于Bt作物对植物—害虫—天敌食物链上各个营养级的影响研究,本文重点分析了Bt毒素对天敌种群结构及生物学的影响。     

郭予元院士在棉铃虫区域性综合防治技术体系研究及应用中的学术贡献——纪念郭予元院士诞辰90周年

郭予元院士带领团队研究人员通过多年协同攻关研究，解析了棉铃虫发生为害规律和自然种群生命表机制，明确了棉铃虫对多种农药抗药性动态并应用于棉田抗药性治理，揭示了黄河流域棉区棉花对不同世代棉铃虫为害的补偿生长规律和防治策略，基于不同世代棉铃虫为害阈值和防治指标创建了准确预报二代棉铃虫发生数量的一代麦田扫网法，开展棉花种质资源抗病虫性鉴定并指导选育多抗棉花系列新品种。通过整合诱杀、选择性杀虫剂、生物农药与化学农药次序使用和局部精准施药等绿色防治技术，组建区域性棉花主要病虫害综合防治技术体系，棉区棉铃虫为害得到有效控制，引领了我国农作物主要病虫害综合防治技术的发展。本文简要回顾了郭予元院士在该领域研究中做出的主要历史贡献。     

Diseases and pests of pigeonpea in eastern Africa: A review

Pigeonpea is one of the major legume crops grown in eastern Africa but has been relatively neglected in terms of research and development. The peas are a rich source of protein and the crop is nitrogen-fixing and drought tolerant. It is an ideal crop for the semi-arid areas of Africa and there is great potential for it to be more widely grown. The large number of pests and diseases which attack pigeonpea in Africa (and elsewhere) is perhaps the main constraint to increased production. The most important pest worldwide is the pod borer, Helicoverpa armigera, but the flowers and pods are attractive to a wide range of insect pests. The most important disease in eastern Africa is Fusarium wilt (Fusarium udum) and considerable effort has been devoted by ICRISAT to developing wilt-resistant pigeonpeas, adapted to cultivation in the region. This paper reviews the literature on pests and diseases of pigeonpea with special reference to eastern Africa and presents some new information on distribution and damage levels for the key pests and diseases.     

Maize Pests and their Importance in Turkey1

Maize and related crops suffer from a large number of insect pests in Turkey but all are not of the same importance in different parts of the country. This paper lists about 80 species, of which only a few ( Sesamia nonagrioides, Helicoverpa armigera, Ostrinia nubilalis , cutworms ( Agrotis spp.), Tanymecus dilaticollis, Gryllotalpa gryllotalpa ) are of primary importance. The pest status and distribution of each species is described.     

Harelish负向调控棉铃虫性信息素生物合成机制的初步研究

性信息素是蛾类昆虫通讯的关键信号分子,其生物合成机制已在家蚕Bombyx mori、棉铃虫Helicoverpa armigera和亚洲玉米螟Ostrinia furnacalis等蛾类中明确了,但其负向调控机制尚不明确。本文探索了Harelish基因在棉铃虫雌蛾性信息素生物合成中的作用。结果发现,Harelish基因在棉铃虫雌蛾中肠、表皮、脑、触角、脂肪体、肌肉和性信息素腺体等7个组织中均有表达,且在羽化后随着性信息素生物的合成和释放而高丰度表达。基于RNAi降低Harelish基因转录水平的表达量后,其性信息素含量和钙调磷酸酶活性均显著上升,表明Harelish通过抑制钙调磷酸酶活性负向调控了性信息素的生物合成。该研究为利用性信息素生物合成的终止信号为分子靶标来防控害虫奠定理论基础。     

2017年玉米重大病虫害发生特点和原因分析

本文总结了2017年我国玉米病虫害发生概况, 重点分析了亚洲玉米螟、二点委夜蛾、黏虫、棉铃虫以及大斑病、南方锈病等近年玉米上发生为害明显的重大病虫害的发生特点, 分析讨论了虫源基数、天气条件、种植制度以及品种抗性和防控水平等因素对玉米病虫害发生的影响。     

Bt抗性和敏感棉铃虫钙黏蛋白及氨肽酶N1表达量的比较

棉铃虫体内的钙黏蛋白（CAD）和氨肽酶N1（APN1）是Bt的主要作用靶标,两种受体蛋白的变化也是棉铃虫对Bt产生抗性的主要原因。本文利用实时荧光定量PCR技术比较了Bt抗性和敏感棉铃虫CAD和APN1的表达量变化,分析受体蛋白表达量变化与抗性的关系。结果表明,与敏感品系相比,抗性品系棉铃虫CAD和APN1的表达量明显降低,1、2龄幼虫的差异达到极显著。在敏感品系中,CAD和APN1的表达量随龄期的增加呈现“V”字形变化,1、2龄幼虫的表达量最高,3、4龄时显著降低,到5龄时表达量又有所增加。抗性品系中CAD和APN1的表达量提前降低,与表达量最高的1龄幼虫相比,2、3龄时表达量显著降低,到4、5龄时又略有回升。说明棉铃虫中肠钙黏蛋白、APN1表达量的下降与抗性相关,且不同龄期棉铃虫幼虫表达量不同。     

Emamectin,a novel insecticide for controlling field crop pests

Emamectin is a macrocyclic lactone insecticide with low toxicity to non-target organisms and the environment, and is considered an important component in pest-management programmes for controlling field crop pests. It is a powerful compound for controlling the cotton bollworm Helicoverpa armigera (Hübner). A spray concentration of 25 mg AI litre-1 in a cotton field resulted in over 90% suppression of H armigera larvae up to day 28 after treatment, while similar mortality of the Egyptian cotton leafworm Spodoptera littoralis Boisduval, under the same conditions, was maintained for 3 days only. Emamectin is a potent compound for controlling the western flower thrips Frankliniella occidentalis (Pergande) under both laboratory and field conditions and its activity on adults was over 10-fold greater than that of abamectin. Spray concentrations of 10 and 50 mg AI litre-1 in Ageratum houstonianum Mill flowers resulted in total suppression of adults up to day 11 and of larvae up to day 20 after treatment. Under standard laboratory conditions, emamectin exhibits a considerable activity on the whitefly Bemisia tabaci (Gennadius) and the leafminer Liriomyza huidobrensis (Blanchard). Further studies are required to evaluate its potential activity on the latter pests under field conditions.     

郴州烟区害虫天敌资源的初步调查

通过2005、2006年对郴州烟区烟草害虫天敌资源的初步调查,共采获烟草害虫天敌约70种,其中已鉴定到种的有46种,包括寄生性天敌7种,捕食性天敌39种;在害虫发生盛期,烟蚜茧蜂的田间最高寄生率达40.3%,棉铃虫齿唇姬蜂寄生于烟青虫、棉铃虫的田间最高寄生率达75.0%,2006年黄花烟93-1上的烟青虫、棉铃虫被此蜂寄生的高达90.5%。     

中黑盲蝽对四季豆豆荚和棉铃虫卵的取食选择性

盲蝽类害虫具有杂食性特点,但已有的取食行为研究主要集中于植食性,缺乏对其食性的全面认识。本文观察了中黑盲蝽在有选择和无选择条件下对四季豆豆荚和棉铃虫卵的取食与选择行为,并利用刺探电位技术分析了其对四季豆豆荚和棉铃虫卵的刺吸行为。研究显示:3种处理上中黑盲蝽总取食时间比例分别为:混合食物(四季豆豆荚和棉铃虫卵)38%、四季豆豆荚33%、棉铃虫卵27%,混合食物上取食四季豆豆荚的时间比例(22%)高于棉铃虫卵(16%)。6h测试时间内,中黑盲蝽刺吸四季豆豆荚时间为6 595s,高于棉铃虫卵(3 641s);单次刺吸时间以在四季豆豆荚上较高(334s)。以上结果表明中黑盲蝽喜欢取食混合食物,且倾向取食刺吸植物。研究结果对进一步解析中黑盲蝽的杂食性,探明其在生态系统中的地位及开发人工饲料有重要科学意义。     

棉铃虫APN基因家族系统进化与功能分析

氨肽酶N（APN）是锌金属蛋白酶M1家族的成员,鳞翅目昆虫中肠刷状缘膜囊泡（brush border membrane vesicles,BBMV）细胞膜上的APN不仅在蛋白消化吸收过程中起着重要的作用,而且是Bt的重要受体蛋白。本研究通过PCR技术克隆得到7条棉铃虫APN基因全长序列,HaAPN1～7（Genbank登录号为MT002819～MT002825）。经生物信息学分析,HaAPN1～7全长为2592～3099 bp,编码863～1032个氨基酸,分子量为110～115 kDa,等电点为4.7～6.4,N端信号肽为15～20 aa。系统进化分析结果表明,HaAPN1～7分属于Class 1～7类别。RT-qPCR结果表明,在敏感棉铃虫5龄幼虫中肠中APN2的表达量最高,APN7的表达量最低;Cry1Ac抗性品系棉铃虫中各类APN的表达趋势与敏感品系一致。取食Cry1Ac、Cry2Ab和Vip3Aa蛋白后棉铃虫中肠APN活性显著降低,取食Cry1Ac和Vip3Aa蛋白后中肠液和BBMV中APN活性都显著降低,而取食Cry2Ab蛋白后只有BBMV上APN活性显著降低;棉铃虫对Cry1Ac、Cry2Ab和Vip3Aa产生耐受性后,中肠液和BBMV中APN活性也都发生显著变化。因此,不同类别的棉铃虫APN在Bt的杀虫机制中可能起到不同的作用,APN活性变化可能与Bt蛋白的降解及抗性演化相关。     

草地贪夜蛾与玉米灌浆期3种常见夜蛾科害虫的形态特征比较

草地贪夜蛾Spodoptera frugiperda(J. E. Smith)是全球预警的一种重大迁飞性农业害虫。2019年1月入侵我国,目前已扩散蔓延至我国24个省份。田间调查发现,在玉米灌浆期,草地贪夜蛾与黏虫Mythimna separata(Walker)、劳氏黏虫Leucania loreyi(Duponchel)和棉铃虫Helicoverpa armigera(Hübner)等夜蛾科害虫常常混合发生,且形态相近,容易混淆,给调查和测报工作带来很大困难。本文详细描述了草地贪夜蛾卵、幼虫、蛹和成虫的外部形态特征,比较了其与黏虫、劳氏黏虫和棉铃虫4个虫态在形态特征上的差别,以期为玉米灌浆期草地贪夜蛾的准确鉴别和田间调查提供依据,并为其精准测报奠定基础。     

昆虫病毒重组增效蛋白的广谱增效活性

室内生物测定表明 ,大肠杆菌表达的粉纹夜蛾颗粒体病毒重组增效蛋白P96可显著或极显著提高棉铃虫核型多角体病毒、苏云金杆菌和阿维菌素对棉铃虫幼虫的致死率 ,分别提高1 6 9.78%、73.90 %和 36 .0 4 % ;对苜蓿丫纹夜蛾核型多角体病毒感染甜菜夜蛾幼虫也有明显增效作用。Na2 CO3 溶解的P96对棉铃虫初孵幼虫有一定致死作用。     

施氮量对棉田主要害虫种群动态的影响

通过不同施氮肥量对棉田主要害虫种群动态影响的研究结果表明,在低、中、高3种施氮肥水平处理条件下,随着氮肥量的增加,棉田棉铃虫落卵量增加,棉苗蚜、棉叶螨种群数量减少,发生为害减轻,但棉伏蚜种群数量增加。中等施氮肥条件下,第二、三代棉铃虫幼虫数量高于低和高施氮肥处理,对棉铃虫幼虫的生长发育和存活较为有利。     

苏云金芽孢杆菌HBF-1芽孢对棉铃虫幼虫生长发育及酶活的影响

苏云金芽孢杆菌HBF-1菌株的芽孢对初孵棉铃虫幼虫无明显杀伤作用,但可以直接影响其正常的生长发育,使幼虫前期体重增加;而后期发育迟缓,历期延长,成虫产卵量明显减少。通过光学显微镜观察发现,用含有HBF-1芽孢的饲料饲喂棉铃虫幼虫,幼虫中肠肠壁细胞遭到破坏;随着虫龄的增大,微绒毛逐渐脱落,有的部位细胞壁破裂。酶活的测定结果表明:初孵棉铃虫幼虫取食含有HBF-1芽孢(100μg/g)的饲料后,幼虫体内的乙酰胆碱酯酶、羧酸酯酶和谷胱甘肽-S-转移酶的活性发生了变化。     

Proteolysis of [14C] azidoatrazine-labelled peptides of pea thylakoid photosystem 2

The efficient synthesis of a family of twelve acidic heterocycles of varying acidity from a single common intermediate facilitates the search for new acidic bioisosteres. An extension of this chemical approach led to a new family of phosphonate replacements in prototypes related to the N-methyl Dasparate (NMDA) antagonist 2-amino-7-phosphonoheptanoic acid (AP7). Acidic isostere design may be facilitated by grouping hydroxylic heterocyclic carboxylic isosteres into one of two electronic classes based on the Gandour hypothesis. The limitations of normal hydroxamic acids as carboxylic acid surrogates suggest that the excellent metabolic stability of reverse hydroxamic acids may be useful in prospective acidic isostere design.     

The effect of piperonyl butoxide on pyrethroid-resistance-associated esterases in Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

Pyrethroid resistance in field populations of Australian Helicoverpa armigera (Hübner) is primarily a consequence of the overproduction of esterase isoenzymes which metabolise and sequester pyrethroid insecticides. Biochemical studies have shown that pyrethroid-resistance-associated esterases in H armigera are inhibited by the insecticide synergist piperonyl butoxide (PBO). Esterase inhibition by PBO did not occur immediately after dosing, but exhibited maximum inhibition 3-4 h after dosage. Esterase activity subsequently recovered until full activity was restored by 24 h. Topical bioassays using a pre-treatment of PBO showed that maximum H armigera mortality was achieved with pre-treatment times corresponding to maximum esterase inhibition. These results demonstrated that, with correct temporal application, PBO can restore pyrethroid efficacy against H armigera. It would also be expected that restoration of efficacy with other conventional insecticides, currently compromised by esterase-based resistance mechanisms, would occur.     

棉铃虫不同品系Gqα基因的比较及其原核表达与纯化

为了阐明Gqα的DNA序列情况,分别以cDNA和总DNA为模板,对Gqα进行PCR扩增,结果发现,Gqα在DNA水平上没有内含子。为了了解不同棉铃虫品系Gqα的变异情况,以实验室5个棉铃虫品系的中肠总DNA为模板,使用Pyrobest高保真酶对该基因进行扩增,测序后翻译成氨基酸序列发现,田间的耐药性品系只有2个氨基酸的变异,即:第163位的非极性A(丙氨酸)变成了极性T(苏氨酸);第353位的非极性V(缬氨酸)变成了碱性R(精氨酸);实验室内毒蛋白品系只有一个氨基酸的变异,第353位的V变成了R;其他2种实验室品系没有任何氨基酸的变异。个别氨基酸的变异可能与棉铃虫对Bt毒素产生抗性相关。将Gqα编码区克隆到表达载体pET21b中,表达出带有6个组氨酸标签的重组蛋白并对其进行了纯化,为进一步研究其功能奠定了基础。     

抗氰戊菊酯棉铃虫细胞色素P450 CYP6B7基因的克隆及分析

以抗氰戊菊酯棉铃虫六龄幼虫中肠组织总RNA为模板,采用特异性引物,通过对反转录-聚合酶链式反应(RT-PCR)的条件进行不断探索和优化,成功克隆出全长为1 557 bp的基因片段(GenBank登录号DQ497428)。该片段包括一个完整的开放阅读框架(1 515 bp)及5'端的42个碱基,编码504个氨基酸残基。与国外报道的细胞色素P450 CYP6B7基因(GenBank登录号AF031468)的核苷酸、氨基酸同源性分别为97.75%和98.81%,为CYP6B7的等位基因。Northern杂交分析表明,抗性品系棉铃虫中肠组织中CYP6B7 mRNA的表达量明显高于敏感品系的,初步表明CYP6B7在棉铃虫对氰戊菊酯的抗药性中起着重要作用。