瑞香狼毒素对菜粉蝶幼虫的杀虫活性

在本实验室前期工作中,发现生长于青藏高原的有毒植物瑞香狼毒对菜青虫具有较好的防治效果.采用微量点滴法研究瑞香狼毒素对菜青虫的触杀活性,以叶片夹毒法和灌喂法研究胃毒活性.在触杀活性试验中,72h的致死中量(LD50)为0.96μg/头,以6.25×103mg·L-1浓度的样品液2μL点滴试虫,即1.25×10μg/头处理组的72h校正死亡率为92.2%.在胃毒活性试验中,72h叶片夹毒法的致死中浓度(LC50)为3.82×103mg·L-1,5.00×104 mg·L-1浓度处理组校正死亡率为91.2%;72h灌喂法的LD50为3.80μg/头,以5.00×104mg·L-1浓度的样品液2μL灌喂试虫,即1.00×102μg/头的处理组的72h校正死亡率为96.8%.结果表明,瑞香狼毒素对菜青虫具有较好的触杀活性和一定的胃毒活性.     

宁南霉素和多抗霉素对黄瓜白粉病的控制作用研究

药效试验结果表明,10％宁南霉素可溶粉剂在80、60g/667m^2剂量下第1次施药后10d对黄瓜白粉痛防治效果分别为73．63％、61．55％,第3次施药后14d防治效果达到74．98％、70．83％;10％多抗霉素素可湿性粉剂在80、60g/667m^2剂量下第1次施药后10d对黄瓜白粉病防治效果分别为70．20％、63．95％,第3次施药后14d防治效果分别达到77．64％、71．82％。上述各处理防治效果均高于对照药剂70％甲基硫菌灵可湿性粉剂80、60g,667m^2处理的同期防效,并且对黄瓜安全,是防治黄瓜白粉病优良生物杀菌剂。     

几种杀菌剂对玉米顶腐病菌的抑制作用

用平板菌落法测定了杀菌剂对玉米顶腐病菌菌丝生长、产孢、孢子萌发及芽管伸长的抑制作用。结果表明:浓度为1000μg/mL的60%氟吗·锰锌可湿性粉剂、15%三唑酮可湿性粉剂、47%腈菌·锰锌可湿性粉剂3种杀菌剂对菌丝生长抑制率为100%。1000μg/mL和500μg/mL供试各杀菌剂能抑制分生孢子萌发,50%多菌灵可湿性粉剂和77%氢氧化铜可湿性粉剂抑制孢子萌发EC50分别为0.2719μg/mL和762.8854μg/mL。供试杀菌剂抑制芽管伸长的EC50差异显著,47%腈菌·锰锌可湿性粉剂EC50为0.1268μg/mL,70%甲基硫菌灵可湿性粉剂EC50为383.9653μg/mL。杀菌剂对分生孢子产生抑制作用显著,产孢量显著小于对照,60%氟吗·锰锌可湿性粉剂能完全抑制孢子形成。     

黍黑孢菌生物学特性和杀菌剂筛选

黍黑孢菌在PDA培养基上生长40 h后开始产孢,但孢子萌发在产孢20 d后。1/2马铃薯葡萄糖汁(PDB)和1%酵母浸出膏显著地促进孢子萌发,萌发率分别达到99%和87.7%,而5%葡萄糖、1%胰蛋白胨和5%蔗糖对孢子萌发促进作用不显著。药剂对菌丝抑制作用的试验结果表明,多菌灵等8种药剂都对黍黑孢菌菌丝生长有着不同程度的抑制作用,其中,50%多菌灵可湿性粉剂效果最好,EC50为0.017μg/mL,EC95为0.098μg/mL。药剂对黍黑孢菌孢子萌发抑制试验结果表明,75%百菌清可湿性粉剂、30%福.腐.百可湿性粉剂、50%多菌灵可湿性粉剂、50%福.福甲胂.福锌可湿性粉剂和28%百.霉威可湿性粉剂都是有效的杀菌剂,其中,百菌清效果最好,其EC50和EC95分别为0.008μg/mL和0.107μg/mL。     

硫酸链霉素对番茄斑疹病病菌的毒力测定

为明确硫酸链霉素对番茄斑疹病病菌的毒力及对病害的防效,采用平板菌落计数法测定其毒力,并对温室内番茄植株进行人工接菌后喷施药剂,测定其防效。结果表明,硫酸链霉素对番茄斑疹病病菌的毒力(EC_50)为0.060 8μg/m L;温室防治试验中,72%硫酸链霉素可溶性粉剂3 500~6 000倍液处理对发病植株的病指防效为95.24%~77.78%,除最低用量6 000倍液处理外,均极显著高于对照药剂46.1%氢氧化铜水分散粒剂1 250倍液处理。从沈阳地区保护地发病番茄上采集的供试斑疹病病菌对硫酸链霉素高度敏感,未产生抗药性。     

不同药剂对水稻细菌性基腐病的防治效果

通过田间试验评价了10种药剂对水稻分蘖期和孕穗期细菌性基腐病的防治效果。结果表明,供试药剂对水稻细菌性基犄病均有一定的防效。分蘖期施药处理中,3%噻霉酮可湿性粉剂和40%春雷·噻唑锌悬浮剂的防效分别为83.22%和65.74%,显著高于72%硫酸链霉素可湿性粉剂(37.92%),其他药剂与72%硫酸链霉素可湿性粉剂均无显著差异。孕穗期施药处理中,9种药剂防效均显著高于72%硫酸链霉素可湿性粉刺(37.58%)。其中,3%噻霉酮可湿性粉剂最高,为73.71%:40%春雷·噻唑锌悬浮剂、25%络氧铜水剂、20%噻唑锌悬浮剂和3%中生菌素可湿性粉剂的株防效均高于60%。建议水稻生产中防治细菌性基腐病可选用3%噻霉酮可湿性粉剂和40%春雷·噻唑锌悬浮剂。     

几种杀菌剂对小麦纹枯病的室内毒力和田间防效

室内采用菌落生长速率法测定了适乐时、烯唑醇、甲基立枯磷、敌力脱、多菌灵和三唑酮等杀菌剂对小麦纹枯病菌的毒力 ,各药剂的EC50 值分别为 :0.030、0.082、0.205、0.224、1.814、1.971、2.065μg/mL。在田间适乐时 (2g/100kg种子)拌种的防治效果为75.2% ,其余各试验药剂喷雾的防治效果为 :烯唑醇 (6.3g/667m2)72.6% ,敌力脱 (5g/667m2)65.5% ,甲基立枯磷 (50g/667m2)61.3% ,多菌灵 (50g/667m2)49.7% ,井冈霉素(10g/667m2)56.3% ,三唑酮 (8.8g/667m2)60.4%。     

8种杀菌剂对西兰花菌核病的防治效果及对制种产量的影响

本文开展了8种杀菌剂对制种西兰花菌核病的防治效果试验。结果表明8种杀菌剂均有防治效果,以40%菌核净可湿性粉剂的防治效果最好,防效为99.19%,比空白对照增产167.05%,千粒重最高,达到5.38g;其次为2亿活孢子/g木霉菌可湿性粉剂和50%腐霉利可湿性粉剂,防效分别为82.39%和81.69%,比空白对照分别增产147.44%和151.70%,千粒重分别为5.34和5.36g。其他杀菌剂的防治效果为51.06%~73.23%,比对照增产76.99%~107.39%,千粒重为4.73~5.28g,空白对照的千粒重为3.23g。综合分析认为,制种西兰花菌核病的防治可选用40%菌核净可湿性粉剂、2亿活孢子/g木霉菌可湿性粉剂和50%腐霉利可湿性粉剂等3种杀菌剂,并交替轮流使用。     

复合高效配方药剂对甘蔗梢腐病防控效果评价

为了筛选防控甘蔗梢腐病的复合高效配方药剂及精准施药技术, 为甘蔗梢腐病精准高效防控提供新产品、新技术支撑, 选用多菌灵、苯菌灵、百菌清、嘧菌酯、吡唑醚菌酯、苯甲·嘧菌酯6种药剂进行田间药效试验和生产示范验证。结果表明, 3个配方药剂50%多菌灵可湿性粉剂1 500 g/hm2+75%百菌清可湿性粉剂1 500 g/hm2、50%苯菌灵可湿性粉剂1 500 g/hm2+75%百菌清可湿性粉剂 1 500 g/hm2和25%吡唑醚菌酯悬浮剂600 mL/hm2分别与磷酸二氢钾2 400 g/hm2和农用增效助剂300 mL/hm2复配后对甘蔗梢腐病均具有良好的防治效果, 其病株率均在8.62%以下, 防效均达90.73%以上, 较空白对照甘蔗实测产量平均增加15 489 kg/hm2以上, 糖分增加1.8%以上, 每公顷用药成本仅270元。本研究显示3个配方药剂是防控甘蔗梢腐病理想的复合高效配方药剂, 可在7月－8月发病初期人工和无人机飞防叶面喷施、7~10 d喷1次, 连喷2次, 可有效控制甘蔗梢腐病暴发流行。     

几种杀虫剂防治水稻二化螟兼治纵卷叶螟试验

田间试验结果表明,50%敌·唑磷乳油1500mL/hm2对水稻二化螟、纵卷叶螟具有很好的防治效果,杀虫效果、保穗效果、保叶效果均达95%以上.15%氟铃·唑磷乳油1350mL/hm2、45%二嗪·唑磷乳油900mL/hm2、18%阿维·唑磷乳油1500 mL/hm2对水稻二化螟、纵卷叶螟有良好的防治效果,杀虫、保穗、保叶效果达90%左右.以上4种杀虫剂对水稻二化螟、纵卷叶螟防治效果显著优于常规药剂90%杀虫单可溶粉剂900g/hm2和50%甲胺磷乳油2 250mL/hm2.4种药剂在试验剂量下对水稻的正常生长无影响,安全性好.     

Investigation of the Mode of Action of Nematode Neuropeptides

The neuropeptide AF2 has a complex set of actions on the dorsal muscle strip of Ascaris suum, including a potentiation of the acetylcholine-stimulated muscle contraction. Caffeine at 100 μm and 5 mm inhibited this potentiation, as did 100 μm theophylline in two out of six studies. The cyclic-AMP-potentiating compounds IBMX, dibutyryl cAMP and forskolin had no effect on the AF2-induced potentiation of the acetylcholine-stimulated muscle contraction. These preliminary data suggest that the potentiating action of AF2 is not mediated by a cAMP pathway.     

厚朴病虫害种类的初步调查

采用标准地法和线路调查法,对湖北恩施市新塘乡双河厚朴基地的厚朴病虫害进行了系统调查,记录主要虫害13种,其中叶部害虫9种,枝干害虫2种,根部害虫2种。厚朴主要病害5种。藤壶蚧、厚朴枝角叶蜂和厚朴新丽斑蚜为湖北省首次报道,小绿叶蝉为厚朴新寄主记录种。同时记录了藤壶蚧的天敌6种,其中寄生小蜂2种,瓢虫4种;厚朴新丽斑蚜的天敌昆虫8种。对藤壶蚧、厚朴枝角叶蜂和厚朴苗木根腐病等重要病虫害的发生规律进行了初步调查,同时提出了防治建议。     

Effects of timing and method of application of Penicillium oxalicum on efficacy and duration of control of Fusarium wilt of tomato

The effects of timing and method of application of Penicillium oxalicum on the control of fusarium wilt of tomato were investigated. Application of P. oxalicum to tomato seedlings in seedbeds reduced disease caused by Fusarium oxysporum f.sp. lycopersici in a growth chamber by 45–49% and in glasshouse experiments by 22–69%. Disease suppression was maintained for 60–100 days after inoculation with the pathogen in the glasshouse. No disease reduction was observed in tomato plants where P. oxalicum was applied to seeds. Treatment with P. oxalicum did not affect the population of F. oxysporum f.sp. lycopersici in the rhizosphere.     

棉花黄萎病菌致病型的AFLP分析

 选用41个棉花黄萎病菌(Verticillium dahliae)代表菌系,在温室条件下,对4个棉花品种鄂荆1号(感)、中棉所12(耐)、文-5(抗)和唐棉2号(抗)进行致病性测定,结果可将供试菌系分为落叶型与非落叶型2类。选取8对AFLP引物PCR扩增的结果中,统计带型稳定、清晰且有多态性的条带,共169条作系统聚类分析,将上述菌系分为2大类,第一类为非落叶型菌系,包括10个非落叶型菌系和1个过渡菌系;第二类为30个落叶型菌系。根据聚类分析建立树状图,发现菌系与地理来源存在一定的相关性,而依据菌系致病力强弱分类则相关关系不大。选用25对EcoRⅠ和MseⅠ引物组合,对供试的41个V.dahliae进行AFLP扩增,筛选到2对引物E64(GACTGCGTACCAATTCGAC)、M53(GATGAGTCCTGAGTAACCG)和E49(GACTGCGTACCAATTCCAG)、M65(GAT-GAGTCCTGAGTAAGAG),能分别扩增出433bp和110bp2条仅为V.dahliae非落叶型菌系独有的特异片段,可将落叶型与非落叶型菌系分开,这2条特异片段被命名为EM₄₃₃和EM₁₁₀。     

百合地下害虫主要种类调查及生物（源）农药筛选

调查了甘肃省临洮县为害百合的地下害虫种类, 并以主要发生为害种类为供试对象, 采用拌土法测定了几种生物（源）农药对主要害虫的室内毒力和致死中时。调查发现小云斑鳃金龟Polyphylla gracilicornis、棕色鳃金龟Holotrichia titanis为主要发生及为害种类, 不同时间发生种类存在差异, 9月份以小云斑鳃金龟幼虫发生为害为主, 发生量占地下害虫总数的66.16%, 平均种群密度为10.48头/m2, 10月份, 则以棕色鳃金龟幼虫发生为主, 发生量占地下害虫总数的96.86%, 平均种群密度为7.79头/m2, 主要取食百合根系和鳞茎, 造成根系数量减少, 鳞茎出现不规则褐色缺口或凹陷斑。药剂筛选结果表明, 1.8%阿维菌素乳油、200亿孢子/g球孢白僵菌粉剂对两种蛴螬均具有较高的杀虫活性和速效性, 药后7 d时, 校正死亡率在82.22%以上, 对小云斑鳃金龟幼虫和棕色鳃金龟幼虫的LC50分别为0.161、0.060 mg/g和5.558×107、0.362×107孢子/g, LT50分别为2.237 d（2.2 mg/g）、1.393 d（2.2 mg/g）和6.645 d（40.0×107孢子/g）、4.940 d（2.0×107孢子/g）, 这两种生物（源）农药对两种蛴螬的LC50和LT50值均略大于两种化学农药25%二嗪磷乳油、40%辛硫磷乳油处理的, 且对小云斑鳃金龟幼虫的杀虫活性均低于对棕色鳃金龟幼虫的杀虫活性, 致死中时则长于对棕色鳃金龟幼虫的致死中时。     

Mode of action of etoxazole

The mode of action of the 2,4-diphenyl-1,3-oxazoline acaricide/insecticide etoxazole has been argued to be moulting inhibition, but experimental results supporting this hypothesis are lacking. This study investigated the effect of etoxazole on chitin biosynthesis in the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae). Etoxazole induced moulting defects in fall armyworm larvae similar, if not identical, to those caused by benzoylphenylureas, a well-known class of insecticidal chitin biosynthesis inhibitors. Furthermore, in contrast to untreated larvae, the chitin content in the integuments of larvae several days after treatment did not differ from that in freshly ecdysed individuals, thus suggesting strong chitin biosynthesis inhibition in vivo. A more detailed investigation of the inhibitory potential by incubating cultured integument pieces from larvae of S. frugiperda with [14C]N-acetyl-D-glucosamine, a radiolabelled chitin precursor, revealed I50 values of 2.95 and 0.071 microM for etoxazole and triflumuron respectively. The incorporation of radiolabel into potassium hydroxide-resistant material was inhibited by etoxazole in a dose-dependent manner. Based on these results, it is concluded that the acaricidal and insecticidal mode of action of etoxazole is chitin biosynthesis inhibition.     

青稞种子带菌检测及杀菌剂消毒处理效果

为了研究青稞种子外部和内部携带真菌情况,比较不同杀菌剂对青稞种子的带菌消毒效果和对幼苗生长的影响,为青稞种子播前包衣处理和种传真菌病害防控提供依据,采用离体平皿法对云南迪庆‘云青1号’、‘云青2号’和‘短白青稞’3个主栽品种进行带菌检测,并对种子进行拌种或浸种处理测定6种杀菌剂对种子消毒效果,分析杀菌剂对种子发芽和幼苗生长的影响。结果表明:供试青稞种子表面携带的优势菌群为青霉(Penicilliumspp.)、镰刀菌(Fusariumspp.);种子内部寄藏的真菌主要为镰刀菌、核腔菌(Pyrenophoraspp.)、附球菌(Epicoccumspp.)、丝核菌(Rhizoctoniaspp.)、链格孢(Alternariaspp.)和木霉(Trichoderma spp.)。青稞不同品种的种子表面及内部携带的真菌种类差异较大。致病性测定表明,镰刀菌对种子萌发和幼苗生长影响最大,后期出现幼苗坏死现象。45%咪鲜胺EW、75%百菌清WP、50%福美双WP对青稞种子携带真菌均有显著抑制作用和消毒效果,50%福美双WP消毒效果最优,达100%;45%咪鲜胺EW、75%百菌清WP、50%福美双WP处理对青稞种子发芽和幼苗生长均无显著影响。     

黑麦草属DNA条形码鉴定技术研究

以毒麦、田毒麦、多花黑麦草、多年生黑麦草、硬直黑麦草、高羊茅与狗牙根等禾本科的7种植物为材料,拟采用 DNA 测序、特异性位点比对、种间遗传距离测定、建立系统树等分析候选 DNA 条形码 psbA-trnH 鉴别黑麦草属常见植物的能力。实验结果表明,以 psbA-trnH 为 DNA 条形码时,建立的系统发育树能较好区分毒麦和田毒麦与其他几种植物。psbA-trnH 序列可以作为黑麦草属植物的潜在条形码。     

Effects of different temperature treatments on dormancy of sclerotia of ten isolates of Sclerotium cepivorum

The variability of dormancy of sclerotia of ten isolates ofSclerotium cepivorum was investigated. Of all isolates tested, the freshly harvested sclerotia were dormant. After drying for 48 hours the sclerotia of six isolates were able to germinate, two isolates stayed dormant and two isolates were infested by hyperparasitic fungi. After storage in soil at 5°C or 20°C, the sclerotia of the different isolates exhibited considerable differences in respect to germination capability, but all isolates showed highest germination after a treatment of 8 weeks at 20°C followed by 8 weeks at 5°C. The sclerotia of all isolates showed an increased capacity to germinate withoutAllium extracts at 10°C after pretreatment at 30°C for 28 days.     

Allelopathy of buckwheat: Assessment of allelopathic potential of extract of aerial parts of buckwheat and identification of fagomine and other related alkaloids as allelochemicals

The allelopathic potential of buckwheat ( Fagopyrum esculentum ) was investigated. Field study showed that living buckwheat reduced weed biomass compared with plots without buckwheat. Laboratory study revealed that root exudates suppressed root and shoot growth of weeds and reduced weed dry weight. Sequential partitioning of the aqueous ethanolic extract of the aerial parts of buckwheat showed that the chloroform extract caused an 80% reduction in radicle elongation of lettuce seedlings at a concentration of less than 100 p.p.m. Fagomine, 4-piperidone and 2-piperidinemethanol were isolated and identified by ¹H and ¹³C nuclear magnetic resonance from the chloroform extract. These compounds caused a 50% inhibition of radicle elongation in lettuce seedlings at concentrations of less than 100 p.p.m. These results suggest that compounds 1, 2, and 3 might act as allelochemicals and affect the growth or germination of different plant species.