4种生防菌对烟草黑胫病的防治作用

烟草黑胫病是烟草生产中分布广泛、最具毁灭性的世界性土传病害,其病原菌可以侵染烟草的任何生育阶段,主要为害大田期烟株。概述芽孢杆菌、假单胞杆菌、放线菌、木霉菌4种生物防治菌对烟草黑胫病的防治进展,为烟草黑胫病生物防治提供参考。     

襄城县烟草黑胫病的发病条件与防治对策

烟草黑胫病在襄城县经常暴发流行,严重影响烟叶生产的发展.通过对烟草黑胫病的调查与分析,提出了防治烟草黑胫病的措施及对策.     

烟草黑胫病防治的关键施药技术研究

为了有效控制烟草黑胫病的发生和为害,选用目前市面上防治效果较好的农药68%精甲霜·锰锌对烟草黑胫病进行防治试验。结果表明,每667 m~2采用精甲霜·锰锌100 g拌底肥窝施和发病初期用68%精甲霜·锰锌1 000倍液对准烟草茎基部灌根,对黑胫病的防治效果为100%。     

烟草黑胫病菌对农田草本植物的寄主范围

烟草黑胫病是烟草生产中的重要病害,对烟草的产量和质量均影响极大[1-2]。烟草黑胫病菌Phytophthora nicotianae var.nicotianae（Breda deHaan）Tucker是引起烟草黑胫病的唯一病原菌,以往的研究均认为,     

青霉菌灭活菌丝体诱导烟草对黑胫病的抗性研究

以青霉菌灭活菌丝体(Drymycelium of Penicillium chrysogenum,DMPC)作为有机肥进行了诱导烟草抗黑胫病的温室试验.研究结果表明,烟草经青霉菌灭活菌丝体诱导处理后,其黑胫病发病率及病情指数明显降低,防治效果明显,而且防治效果与青霉菌灭活菌丝体浓度及处理时间有关;烟草过氧化物酶(POD)和多酚氧化酶(PPO)等2种细胞防御酶活性提高,对黑胫病的抗性增强.     

二氢茉莉酸丙酯诱导烟草抗黑胫病作用研究

研究了二氢茉莉酸丙酯(PDJ)对烟草黑胫病的控制作用,结果表明:离体条件下,PDJ对烟草黑胫病Phytophthora parasitica Var. nicotianae的菌丝生长、孢子囊产生、游动孢子释放及萌发均无明显的抑制作用;PDJ处理后显著减轻了烟草幼苗黑胫病的病情,其最佳处理浓度为100 mg/L,最佳处理时间是接种前3 d,持效期在15 d以上;并且PDJ 100 mg/L处理烟苗下部第3片叶后,可使上部未处理叶片病情显著减轻。表明PDJ诱导了烟草幼苗对黑胫病的抗性。     

几丁寡糖对烟草黑胫病的控制效应及其机制

在室内条件下,采用菌丝生长速率法测定了几丁寡糖对烟草黑胫病菌的抑制作用,继而在温室盆栽和人工接种条件下,分别测定几丁寡糖、木霉、几丁质、几丁寡糖+木霉、几丁寡糖+木霉+几丁质等5种处理对烟草黑胫病的防治效果。结果表明,几丁寡糖在离体条件下对烟草黑胫病菌菌丝生长无抑制作用,但在盆栽试验中对烟草黑胫病具有显著防治效果。5种处理中,几丁寡糖单独处理对烟草黑胫病的防治效果最高,为57.81%,其次为几丁寡糖+木霉+几丁质和几丁寡糖+木霉处理,分别为53.49%和52.49%。在温室条件下对烟草植株施用几丁寡糖及人工接种黑胫病菌后10天内,几丁寡糖能显著提高烟草体内的SOD、POD、PPO和几丁质酶活性,且活性峰值分别比对照提高96.30%、136.36%、10.34%和9.10%。     

烟草青枯病与黑胫病绿色防控关键技术

推进烟草青枯病(Tobacco Bacterial Wilt)和黑胫病(Tobacco Black Shank)的绿色防控是烟草绿色防控重大专项实施的重要目标任务之一.本文明确了烟草青枯病和黑胫病绿色防控的指导思想,介绍了监测预警的基本方法,提出了土壤改良和品种选择的基本对策;系统介绍了以微生态调控为核心,以育苗基质拌菌、有机肥拌菌、抗性诱导和营养平衡为主导的"4个平衡"控制病害的绿色防控技术;并配套了精准用药的主要方法,总结出了青枯病黑胫病绿色防控操作规程.对于全面推进烟草青枯病和黑胫病的绿色防控具有重要的指导意义.     

烟草黑胫病防治技术

烟草黑胫病是由烟草疫霉菌引起的一种毁灭性土传真菌病害。常年在烟草种植区发生,该病菌容易对化学药剂产生抗药性,在防治上比较困难。针对烟草黑胫病的发生特点,结合烟叶生产实践,介绍烟草黑胫病防治技术,供生产上参考。     

烟草黑胫病拮抗根际芽胞杆菌FB-16的筛选鉴定及其抑菌活性

为获得对烟草黑胫病有较强生防效果的拮抗细菌,从健康烟草根际采集30份土壤样品,分离纯化得到347株细菌,经病原真菌定向筛选后得到1株对烟草黑胫病菌等病原真菌拮抗活性较好的细菌FB-16,其对烟草黑胫病菌的抑菌带宽为23mm。采用菌丝生长速率法、作用机制试验、温室防病试验测定FB-16的抑菌作用,并通过形态学特征、生理生化特征及16S rDNA序列分析对菌株进行鉴定。结果显示,菌株FB-16发酵液对烟草黑胫病菌菌丝生长抑制率为95.96%;其代谢产物对烟草黑胫病菌菌丝有致畸作用;菌株FB-16为解淀粉芽胞杆菌Bacillus amyloliauefaciens(Gen-Bank登录号为JN245982);饱和度25%硫酸铵获得的抑菌物质对烟草黑胫病菌的抑菌活性较高,抑菌圈直径达42.00 mm;FB-16活性产物处理的烟草植株在接种烟草黑胫病菌7天后的防治效果为69.96%。表明菌株FB-16在烟草黑胫病生物防治中具有潜在的利用价值。     

Localization of metabolic sites of action of herbicides

Time- and concentration-course studies were conducted to determine the effect of thirteen herbicides on photosynthesis, respiration, RNA synthesis, protein synthesis, and lipid synthesis using isolated single leaf cells. Each herbicide was from a different chemical class. Appropriate ¹⁴C-substrates and product purification procedures were used for each process prior to liquid scintillation counting. The most sensitive metabolic site of inhibition was photosynthesis for atrazine, bromacil, dichlobenil, monuron, and paraquat; RNA synthesis for dalapon and dinoseb; protein synthesis for chlorpropham; and lipid synthesis for CDAA, chloramben, 2,4-D, EPTC, and trifluralin. However, with several herbicides, one or more process was almost as sensitive as the one mentioned above. All herbicides inhibited more than one process, and the most sensitive site of inhibition may not be the same process that was inhibited the greatest at the maximum concentration and maximum exposure time used. Therefore, a concept of metabolic sites of action, rather than a primary site of action, appears to be more meaningful for herbicides.     

福寿螺配偶个体大小选择性初步观察

通过野外观察与实验研究,掌握了福寿螺的婚配体制及其配偶选择性规律。福寿螺与多数低等动物一样,其婚配属于乱交制,无固定配偶;雌螺对与其交配的雄螺个体大小没有选择性,而雄螺对雌螺的个体大小有选择性,倾向于与较大个的雌螺交配。     

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。     

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.     

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.     

Mode of action of meturine

The effect of meturine on the light processes of photosynthesis was studied.Meturine is a herbicide for weed control in potato and cotton crops. It is a N-phenyl—N-hydroxy—N′-methylurea.The experiments were carried out on isolated pea and spinach chloroplasts.When examining photosystem I, reduced DPIP was used as an electron donor, whereas methyl-viologen served as an electron acceptor. When examining photosystem II, DPIP represented the electron acceptor.The obtained experimental results have pointed to the absence of the effect of meturine upon the photoreaction I.Unlike N-phenyl—N′, N′-dimethylureas (CMU, DCMU) meturine has been a very weak inhibitor of photoreaction II.The authors explain the photoreaction II inhibition of chloroplasts from plants treated with herbicidal doses of meturine by conversion of N-phenyl—N-hydroxy—N′-methylurea into Hill reaction inhibitor(s). N-Phenyl—N′-methylurea can be one of such meturine metabolites.Meturine herbicidal action is accounted for by meturine transformation into Hill reaction inhibitor(s) in the plant tissues.     

甲基硫菌灵标样的制备

本文介绍了用进口甲基硫菌灵样品，采用溶剂萃取，高速离心，重结晶，高效液相色谱，红外光谱等分析方法进行系统分离与鉴定，得到其标样的方法。