几种虫生真菌对枸杞负泥虫的致病性及应用

室内用浸溃接种法测定了2种不同寄主来源的球孢白僵菌(Beauveria bassiana)2菌株和金龟子绿僵菌(Metarhizium anisopliae)1菌株对枸杞负泥虫的毒力.结果表明,3种菌株对枸杞负泥虫均具有毒杀作用.绿僵菌IPPCKAS2029菌株表现了较高的毒力,对2龄幼虫的致死中时(LT50)4.39 d,校正死亡率为100%;对成虫的致病力低于幼虫,致死中时(LT50)10.65 d,校正死亡率73.8%.球孢白僵菌FW-05、Z-28两菌株的毒力弱于前者,对2龄幼虫的致死中时(LT50)分别为6.85 d和7.78 d,校正死亡率分别为86.5%和82.7%;对成虫的致死中时(LT50)分别为16.18 d和18.92 d,校正死亡率分别为61.9%和55.6%.     

黄绿绿僵菌KM1104对灰飞虱的毒力

为了筛选防治灰飞虱的高毒力生防真菌菌株及明确黄绿绿僵菌对灰飞虱的侵染致病温度条件,室内测定了黄绿绿僵菌KM1104菌株在24~30℃下对灰飞虱成虫及3龄若虫的毒力。结果表明:黄绿绿僵菌菌株KM1104对灰飞虱成虫和3龄若虫均具有较强的毒力,其中对成虫的毒力高于3龄若虫,在24~30℃下对成虫和3龄若虫的LC50分别为1.45×103~7.14×104和7.25×103~3.69×105孢子/mL,致死中时LT50分别为3.02~11.53d和6.85~11.58d。不同温度下黄绿绿僵菌KM1104菌株对灰飞虱的毒力不同,其中30℃下毒力最强,对成虫和3龄若虫的致死中浓度LC50分别为1.45×103和7.25×103孢子/mL,接种1.01×105~1.01×108孢子/mL后对成虫和3龄若虫的致死中时LT50分别为3.02~6.86d和6.85~9.35d。综合以上结果,黄绿绿僵菌菌株KM1104具有良好的灰飞虱生防制剂开发潜力,且在30℃下使用致病力最强。     

Resistance of Rotala indica Koehne var. uliginosa Koehne to sulfonylurea herbicides

The present paper aims to quantify the degree of resistance development in Rotala indica Koehne var. uliginosa Koehne to sulfonylurea (SU) herbicides based on whole plant responses. Seeds of resistant (from Omagari City, Akita Prefecture, Japan) and susceptible (from Tsukuba City, Ibaraki Prefecture, Japan) R. indica plants were seeded in 200 cm² pots. The plants, at the 1.5 leaf stage, were blanket-applied with different rates of three sulfonylurea herbicides: bensulfuron methyl (BSM), pyrazosulfuron ethyl (PSE) and imazosulfuron (ISN). Of the three herbicides, the weed appears to have developed the highest degree of resistance to BSM. The resistant/susceptible (R/S) values based on mortality, root length and dry weight are consistently highest at 197, 157 and 101, respectively. Responses based on shoot length, however, showed a higher R/S value for PSE. Roots of R. indica are more sensitive to higher rates of SU herbicides than the shoots. Indeed, a high degree of resistance to SU herbicides have evolved in R. indica , for which the recommended field rates are not enough for effective control of the weed.     

昆虫病原线虫JLSY 003的鉴定及其生物学特性测定

经28S rDNA和ITS序列分析,从吉林省松原市土样中分离到的昆虫病原线虫JLSY 003为Oscheius myriophila品系.本研究以大蜡螟末龄幼虫为寄主,测定该线虫的生物学特性.结果表明,JLSY 003浓度为80IJs/larva时具有较高的侵染力,致死中时间LT50为15.409 h,侵染24、48h...     

蜡蚧轮枝菌对月季长管蚜的毒力测定

研究结果表明蜡蚧轮枝菌对月季长管蚜有较强的致病性,孢子浓度2.0×105个/mL时可造成大量月季长管蚜感染死亡,其LT50=（6.62±0.14）d; 而高浓度2.0×108个/mL对月季长管蚜感染致死的LT50=（4.69±0.16）d,第8天的死亡率达93.6%,致死中时随浓度增加而缩短。第5天的致死中浓度为（1.72±0.18）×107个/mL,第8天为（1.53±0.15）×104个/mL,致死中浓度随时间增加而减小。     

50％多·锰锌可湿性粉剂防治苹果主要病害的应用技术研究

50%多·锰锌可湿性粉剂500、600、700倍液室内对苹果轮纹病、炭疽病菌菌丝生长及孢子萌发的抑制效果均为100% ,对斑点落叶病菌菌丝生长及孢子萌发的抑制效果在70.21%以上优于单剂代森锰锌、多菌灵的效果 ;其对上述3种病菌的抑制中量 (EC50)小于单剂 ,共毒系数均>200,增效显著。田间对斑点落叶病和褐斑病的防效在81.12%以上 ,显著优于单剂 ,对轮纹病、炭疽病生长期及贮藏期的防治效果分别为97%～99.2%、70.9%～87.6%和87.1%～95.5%、50.5%～86.2% ,优于单剂代森锰锌的效果 ,优于或相当于多菌灵的效果。     

Comparative biological activities of a plaque-purified variant and a Turkish native isolate of SpliNPV-B against Spodoptera littoralis (Lepidoptera: Noctuidae)

The noctuid moth Spodoptera littoralis (Boisduval) is an important pest of many cultivated plants worldwide and five different geographical Nucleopolyhedrovirus (NPV) strains of this pest have been isolated to date. Two of these, a plaque-purified variant of the S. littoralis NPV from Morocco (SpliNPV-M2) and a SpliNPV isolated from field-infected S. littoralis larvae found in Turkey (SpliNPV-TR1), were compared biologically in terms of infectiveness (median lethal dose, LD50) for third instars and in terms of virulence (median lethal time, LT50) for neonates and third-instar S. littoralis larvae. The LD50 values of SpliNPV-TR1 and SpliNPV-M2 were 20.73 and 185.21 occlusion bodies (OBs)/larva, respectively, with non-overlapping confidence limits indicating they were significantly different. Thus, SpliNPV-M2 was found to be significantly less infective (about nine times higher LD50) than SpliNPV-TR1. The LT50 values of neonates for SpliNPV-M2 and SpliNPV-TR1 were 37 and 43.9 h at a concentration of 10(6) OBs ml(-1), respectively. For these same isolates, the LT50 values at a concentration of 3 x 10(6) OBs ml(-1) were calculated as 35.6 and 41.7 h, respectively. The LT(50) values of third instars for SpliNPV-M2 and SpliNPV-TR1 were 147.4 and 160.5 h, respectively, at a dose of 3000 OBs/larva and 145.4 and 152.4 h, respectively, for the same isolates at a dose of 20,000 OBs/larva. On the other hand, Helicoverpa armigera (Hübner) and Agrotis ipsilon (Hufnagel) revealed a lack of lethality of the SpliNPV-TR1 isolate.     

几种常用杀虫剂对异色瓢虫的敏感性测定

在实验室及田间罩笼条件下，进行了异色瓢虫对8种杀虫剂的敏感性测定。结果显示：8种供试药剂对异色瓢虫幼虫的毒性（LC50值）差异很大，矿物油类药剂敢死虫对异色瓢虫最安全，其LC5。值高于其田间常用有效剂量；苦参素植物保护剂、吡虫啉、阿维菌素对异色瓢虫成虫的LC50值也高于各自的田间使用剂量，但对幼虫的LC50值却介于推荐的田间有效剂量与高限剂量之间，对瓢虫幼虫安全有一定威胁。     

91种农药制剂对家蚕的急性毒性研究

为评价农药对家蚕的环境安全性,作者采用毒叶饲喂法在室内测定了91种农药对家蚕(Bombyx mori L.)的急性毒性,并根据其毒性范围进行分级,结果表明:有30种药剂的LC50<0.5mg/kg桑叶,属于剧毒级,包括甲氨基阿维菌素苯甲酸盐、阿维菌素、高效氯氰菊酯、联苯菊酯、虫酰肼、三唑磷等;有15种药剂的LC50为0.5～20mg/kg桑叶,属于高毒级,如丁硫克百威、虫螨腈、杀铃脲、氟虫腈、噻嗪酮、高渗氯胺磷、敌百虫;19种药剂的LC50为20～200mg/kg桑叶,属于中等毒级;27种药剂的LC50>200mg/kg桑叶,属于低毒级。     

三种不同来源胆碱酯酶用于农药残留快速检测的比较

本实验以罗非鱼肌肉胆碱酯酶、Sigma C2888乙酰胆碱酯酶及商品化农药残留检测试剂盒为检测酶,使用酶抑制法进行检测,比较了12种不同浓度农药对这三种酶酶活力抑制情况。结果表明,9种有机磷杀虫剂和3种氨基甲酸酯类杀虫剂对罗非鱼肌肉胆碱酯酶都有较强的抑制作用,IC50值均10×10-6μg/m L。敌敌畏对胆碱酯酶的抑制作用最强,其IC50值为0.031×10-6μg/m L;灭多威的抑制能力最弱,IC50值为50.91×10-6μg/m L。8种农药(丁硫克百威、敌敌畏、辛硫磷、对硫磷、甲胺磷、乐果、马拉硫磷、甲基异柳磷)对罗非鱼肌肉胆碱酯酶的抑制作用Sigma C2888,检测试剂盒ACh E对7种农药(呋喃丹、灭多威、辛硫磷、对硫磷、甲胺磷、马拉硫磷、敌百虫)的灵敏度高于Sigma C2888。与罗非鱼肌肉胆碱酯酶比较,呋喃丹、灭多威、辛硫磷、甲胺磷、敌百虫对检测试剂盒胆碱酯酶的抑制更强。     

夜蛾斯氏线虫对松树上松墨天牛的毒力测定和室内防治效果

在室内测定了夜蛾斯氏线虫对松枝中松墨天牛的致死中量和致死中时。将TDM模型引入试验结果的分析中，72h后松墨天牛老龄幼虫的LD50为1．2767条／头，LB50为1．6716d；蛹的LD50为1．4417条／头，LB0为1．2627d。结果表明：随着时问的延长，LD50逐渐减少；随着线虫剂量的增加，LT50逐渐缩短。通过线虫寻向移动速度试验得出：夜蛾斯氏线虫与松墨天牛幼虫相距4—10cm情况下的效果较好。通过不同防治方法试验得出：施入夜蛾斯氏线虫防治松墨天牛，12d后，浸泡法的效果最好，海绵法次之，注射法较差。     

内生短短芽胞杆菌011菌发酵滤液抑菌活性研究

为明确短短芽胞杆菌011菌株在植物病害生物防治中的应用潜力,采用平皿打孔法测定011菌发酵滤液抗菌谱及其活性稳定性;采用孢子萌发法测定011菌发酵滤液对番茄早疫病菌最低抑菌浓度MIC及EC50;并显微观察其对番茄早疫病菌菌丝及孢子抑制作用.结果表明:011菌发酵滤液对8种植物病原真菌均有抑制作用,其中对番茄早疫病菌抑制作用较强,抑菌带宽度为5.5 mm;对番茄早疫病菌菌丝及孢子均有致畸作用;对番茄早疫病菌最低抑菌浓度MIC为30％,有效抑菌中浓度EC50为9.64％;其活性具有较好的热稳定性(100℃处理1h活性保持在95％0),耐酸性及抗紫外线(pH2.0处理及紫外20 W,30 cm照射120 min,活性保持不变).     

Susceptibilities of some aquatic ferns to paddy herbicide bensulfuron methyl

Paddy herbicides have the potential to cause adverse effects on non-target plants. Susceptibilities of some aquatic ferns ( Azolla japonica Franch. et Savat., Isoetes japonica A. Braun, Marsilea quadrifolia L. and Salvinia natans All.) and duckweeds ( Lemna minor L. and Spirodela polyrhiza Schleid.) to paddy herbicide bensulfuron methyl (BSM) were evaluated with a 20 day exposure experiment using 200 cm² pots. The BSM concentrations in the surface water of monitoring pots with no plants dissipated exponentially with half lives of 3.5 and 3.9 days at application rates of 15 and 150 g ha⁻¹, respectively. The BSM concentrations in the surface water 1 day after application in the culture pots were comparable among plant species, and were lower than those in the monitoring pots. Bensulfuron methyl reduced the plant growth in all species. I . japonica showed the lowest intrinsic relative growth rate (RGR) and the lowest susceptibility with an effective dose resulting in 50% growth inhibition (ED₅₀) of 21 g ha⁻¹. Except for I . japonica , the RGR of the duckweeds was similar to the ferns, and ED₅₀ for the duckweeds was higher than the ferns. ED₅₀ for Sa . natans , A . japonica and M . quadrifolia were 1.1, 1.8 and 1.2 g ha⁻¹, respectively, which were smaller than 1/20 of the recommended field dose (51–75 g ha⁻¹) and ranged from 1/2 to 1/6 of ED₅₀ for L . minor and Sp . polyrhiza (6.5 and 3.2 g ha⁻¹, respectively). These results suggest that BSM application in paddy fields and its runoff in some localities is expected to have adverse effects on the growth of Sa . natans , A . japonica and M . quadrifolia .     

Root Uptake and Xylem Translocation of Pesticides from Different Chemical Classes

A pressure-chamber technique was used to study the root uptake and xylem translocation of some fungicides, herbicides and an insecticide from different chemical classes in detopped soybean roots. Physiological parameters such as K⁺ leakage from roots, K⁺ concentrations in the xylem sap, and protein and ATP levels in the root cells were measured so as to evaluate any potential damage of this technique to the root system. HPLC was used to quantify the compounds in the xylem sap. The pressure-chamber technique has proved useful to study the root uptake and translocation of pesticides, does not damage the root system, and allows one to obtain appreciable volumes of xylem sap that can be analysed directly by HPLC, thus avoiding dependence on the availability of radio-labelled compounds. The concentration of each pesticide in the xylem sap showed a steady-state kinetic profile. Non-linear regression analysis was used to calculate the steady-state concentration and the time required to achieve 50% of the steady-state concentration (TSSC₅₀). TSSC₅₀ was well correlated with log K_ow; the more lipophilic the compound the more time was required to reach the steady-state concentration. The efficiency of translocation was assessed by the transpiration stream concentration factor (TSCF) and a non-linear relationship between TSCF and log K_ow was observed. The highest TSCF values were measured for those compounds with log K_ow values around 3, a lipophilicity value similar to that reported earlier in an analogous experiment with detopped soybean plants but slightly higher than that reported in earlier experiments with intact barley plants. Lower TSCF values were obtained with chemicals with log K_ow values below as well as above 3. © 1997 SCI.