烟田小地老虎高致病力球孢白僵菌的筛选

为了筛选出对烟田小地老虎(Agrotis ipsilon)具有高致病力的球孢白僵菌(Beauveria bassiana)菌株，综合考虑菌株的生长速率、产孢量、孢子萌发率以及试虫死亡率等多项指标，对9株球孢白僵菌的致病力进行了综合评价。结果发现，Bb22菌株生长最快，Bbz2菌株的产孢量和孢子萌发率均为最高，Bb324菌株对小地老虎2龄幼虫的致病力最强。Bb324菌株处理8 d后，试虫校正死亡率为70.37%，显著高于其他菌株；其致死中时间(LT₅₀)为4.40 d，显著短于其他菌株。Bb324处理8 d的致死中浓度(LC₅₀)为2.92×10⁷孢子/mL。结果表明Bb324菌株对小地老虎2龄幼虫具有较强的致病力，在烟田小地老虎生物防治中具有潜在的应用价值。     

八株蜡蚧轮枝菌的生物学特性及其对烟蚜致病性的影响

为明确田间自然罹病烟蚜僵虫上的真菌种类和筛选出对烟蚜的高毒力菌株,将采集的烟蚜僵虫经过常规分离、纯化,进行了菌落生长、产孢量、形态观察、ITS序列测定、系统发育树构建以及对室内烟蚜毒力测定的研究。结果表明,从烟蚜僵虫体上分离纯化出8株菌株,经生物学特性观察、ITS序列对比和构建系统发育树准确鉴定出这8株菌株均是蜡蚧轮枝菌。综合生物学培养和毒力测定结果,得出菌株V4为优良菌种,具有产孢量高（1.89×10⁹个/皿）,生长速率快（15 d菌落直径达到68.78 mm）,对烟蚜毒力强（第7天的校正死亡率为84.99%,LT₅₀为4.51 d）的特性,具备田间持续控制烟蚜的潜力。     

贮烟仓库中苏云金芽孢杆菌对烟草甲的杀灭活性

为研究苏云金芽孢杆菌(Bt)防治贮烟害虫的可行性,从全国7个主要卷烟厂的不同贮烟仓库中采集到不同类型的样品521份,采用醋酸钠抑制选择法从其中的225份样品中分离获得Bt952株,其分布率为100%,检出率为43.19%,用其中600株的发酵液对2~3龄烟草甲幼虫进行了初步毒力测定。结果表明,有18株分离株对烟草甲幼虫具有较高的生物活性,药后9d烟草甲幼虫的校正死亡率均达73%以上。     

5种生物农药对烟蚜和食蚜瘿蚊的毒力测定及安全性评价

为筛选出对食蚜瘿蚊安全的生物农药,选用5种常用的生物农药对烟蚜及食蚜瘿蚊幼虫（喷雾法）和食蚜瘿蚊成虫（药膜法）进行了毒力测定和安全性评估。结果表明,无论处理24 h还是48 h,对烟蚜毒力较高的是甲维盐和苦参碱,LC₅₀分别为2.166和3.695 mg/L（24 h）,1.567和2.874 mg/L（48 h）;对食蚜瘿蚊幼虫的毒力较高的是鱼藤酮,LC₅₀为18.137 mg/L（24 h）、13.771 mg/L（48 h）,对成虫的毒力较高的是多杀菌素,LC₅₀为7.249 mg/L（24 h）、4.125 mg/L（48 h）。因此5种生物农药中苦参碱、甲维盐、苏云金杆菌对烟蚜和食蚜瘿蚊的选择性较高,适宜在田间与食蚜瘿蚊联合应用防控烟蚜。     

烟草根黑腐病根际拮抗菌的筛选、鉴定及其促生防病效果

为挖掘对烟草根黑腐病菌有较高拮抗效果的根际促生菌资源,从四川广元和陕西汉中等地采集30份烟草根际土壤,以烟草根黑腐病菌为靶标,采用温度筛选法和平板对峙法分离筛选出有高效拮抗活性的菌株,并对该菌株进行系统发育分析,采用抗生素标记法和温室盆栽法测定菌株LY79的定殖规律、对烟草的促生效果以及对烟草根黑腐病的防治效果。结果表明：（1）从烟草根际土壤分离到一株烟草根黑腐病高效拮抗菌株LY79,经形态学、生理生化鉴定结合16S rRNA和持家基因ropB分析将菌株LY79鉴定为解淀粉芽孢杆菌（Bacillus amyloliquefaciens）。（2）抗生素标记菌株LY79^A在烟草根际土定殖规律为先下降后上升再下降最终趋于稳定,且施药40 d后仍能在烟草根际土、根系、茎、叶分离到1.34×10⁶、2.91×10⁴、1.81×10⁴、1.01×10⁴ CFU/g的菌株LY79^A,说明其定殖能力较强。（3）菌株LY79对烟草促生效果较好,处理60 d后,烟草的株高、茎粗、整株干质量、根干质量分别增加了34.68%、37.85%、103.79%、72.55%。（4）1×10⁹ CFU/mL浓度的菌株LY79发酵液对烟草根黑腐病的盆栽防效达71.54%,仅略低于对照药剂70%甲基托布津500倍液。解淀粉芽孢杆菌LY79在烟草根黑腐病防治中具有较大的应用潜力。     

高良姜根茎粉剂对烟草甲的毒杀作用

为明确高良姜根茎粉剂对储烟害虫烟草甲的毒杀作用,采用药膜法测定了5种不同浓度下高良姜根茎粉剂对烟草甲卵、幼虫、蛹、成虫4种虫态的毒力作用.结果表明,高良姜根茎粉剂对烟草甲成虫具有一定的触杀作用,并且随着处理浓度增大、处理时间的延长而增强,但对其幼虫无触杀作用.在处理浓度范围内,在16 g/ m2的处理浓度下对烟草甲成虫的校正死亡率最高可达45%以上.高良姜根茎粉剂对烟草甲卵和蛹也都有较强的触杀作用,最高校正死亡率均达到60%以上.因此,高良姜根茎粉剂是一种具有较大应用潜力的植物源杀虫剂.     

利用废弃烟梗发酵生产白僵菌的响应面优化

为实现废弃烟梗资源化利用,以废弃烟梗为主要发酵底料,白僵菌产孢量为响应值,采用响应面法（Response Surface Methodology,RSM）对烟梗发酵生产白僵菌的条件进行了优化。通过Plackett-Burman（PB）试验筛选出影响废弃烟梗发酵生产白僵菌最显著的因素,设计最陡爬坡试验逼近最佳条件区域,进一步设计Box-Behnken Design（BBD）响应面优化,分析并确定最佳条件。结果表明,当培养时间为9.40 d,蛋白胨含量1.21%,酵母粉含量1.03%时,白僵菌孢子产量预测最优值为1.17×10¹⁰个/g,实际孢子产量为1.13×10¹⁰个/g,拟合度达到96.58%,白僵菌产孢量显著提高。因此,采用该方法优化得到的最佳发酵条件合理而有效,对烟草生物防治以及烟梗废料的综合利用具有实际应用价值。     

山苍子精油抑制黄曲霉菌的生长和产毒作用研究

山苍子精油是一种纯天然植物精油,本文研究了其对黄曲霉生长、代谢和毒素产生的抑制作用,探讨了山苍子精油对黄曲霉菌的抑菌能力和作用机理。本研究将花生放置于自然环境染菌并分离纯化目标菌,采用形态学并结合ITS序列法进行菌株分类鉴定;结合抑菌圈、抑菌率和最低抑菌浓度(MIC)的测定探讨山苍子精油对黄曲霉菌的抑制能力;进行了山苍子精油影响黄曲霉孢子萌发率、生长曲线和黄曲霉毒素B1产生的实验研究;从细胞膜渗透性、细胞酶活性的变化探讨了山苍子精油抑制黄曲霉的作用机理。实验结果表明:从腐败花生中分离筛选出菌株HB₂,经ITS序列法鉴定为黄曲霉(Aspergillus flavus);黄曲霉素测定结果显示其含有黄曲霉素B1(AFB1),质量浓度为3.4×10³μg·kg^-1(纯湿菌体);抑菌圈随精油浓度的增大明显变大,对黄曲霉的最低抑菌体积分数(MIC)为0.800μL·mL^-1;孢子萌发率、牙管长度、黄曲霉菌体的生长量和AFB1的浓度随培养液中精油浓度的增大呈显著下降趋势,当山苍子精油浓度为0.100μL·mL     

短小芽孢杆菌与化学杀细菌剂协同防治烟草青枯病研究

为探究短小芽孢杆菌与化学杀菌剂联合防控烟草青枯病的可行性,分别采用改良抑菌圈法和平板菌落计数法测定7种杀菌剂和短小芽孢杆菌AR03对青枯雷尔氏菌的毒力及杀菌剂与AR03的生物相容性,同时采用Horsfall法确定杀菌剂和AR03的复配比例。室内毒力试验结果表明,7种杀菌剂和AR03对青枯雷尔氏菌的生长均有较好的抑制作用。7种杀菌剂的毒力大小依次为三氯异氰尿酸、氯尿·硫酸铜、噻菌铜、溴菌·壬菌铜、甲霜·福美双、噻唑锌和中生菌素,EC₅₀值介于101.02~212.70 mg/L之间。浓度为1.0×10⁵~1.0×10⁹ cfu/mL的AR03对青枯雷尔氏菌的抑菌率介于26.13%~73.54%之间,呈现浓度依赖性。生物相容性分析发现7种供试药剂与AR03的生物相容性差异较大,短小芽孢杆菌AR03与噻菌铜、噻唑锌、甲霜·福美双生物相容性较好,尤其是噻菌铜表现最好,测试浓度100 mg/L时,菌落数大于1×10⁷cfu/mL。综合杀菌剂对青枯病菌的毒力及其与AR03生物相容性,噻菌铜表现最优。噻菌铜（EC₅₀=175.21 mg/L）与AR03（EC₅₀=6.84×10⁶ cfu/mL）复配剂在体积比为5∶5时,对青枯雷尔氏菌的抑制效果显著,增效作用明显,增效比率值I_R值为1.482。室内盆栽试验结果表明,菌药复配剂的防效（68.77%）明显优于单剂噻菌铜和生防菌AR03的防效,且混配剂中噻菌铜使用量只有单剂的1/2,大幅降低了化学药剂的使用量。     

连翘挥发油对两种烟草仓储害虫的毒杀作用

为开发新型烟草仓储防护剂,研究连翘果实挥发油的化学成分及其对烟草仓储害虫的杀虫活性。通过GC-MS分析了连翘果实挥发油的化学成分,运用柱色谱和核磁共振方法分离并鉴定化合物,通过熏蒸、触杀试验测试挥发油及单体成分活性。结果表明,连翘挥发油对烟草甲和赤拟谷盗熏蒸活性的LC₅₀值分别为8.94和7.68 mg/L;触杀活性的LD₅₀值分别为23.66和30.13 μg/头。单体化合物中,4-萜品醇对烟草甲的熏蒸和触杀毒性最强（LC₅₀值为6.90 mg/L;LD₅₀值为8.62 μg/头）。另外,α-蒎烯,γ-萜品烯和4-萜品醇对两种仓储害虫均具有较好的熏蒸和触杀活性。因此,连翘挥发油及其单体化合物对烟草甲和赤拟谷盗均具有一定防治作用。     

Desiccation increases the efficacy of Beauveria bassiana for stored-grain pest insect control

The effect of desiccation stress on the efficacy of Beauveria bassiana for controlling stored-product insects was investigated in laboratory bioassays. The mortality of B. bassiana-treated Plodia interpunctella larvae was greater at a vapor pressure deficit (VPD) of 2.42 or 1.87 kPa than at 1.06 kPa. Moisture also had significant effects on the mortalities of adult rice weevils, Sitophilus oryzae and maize weevils, Sitophilus zeamais. Mortality of S. zeamais was higher at 2.42 and 1.87 kPa than at 1.06 kPa, while mortality of S. oryzae was higher at 1.87 kPa than at either 2.42 or 1.06 kPa. Higher control mortality at the higher two VPDs indicated that S. zeamais was less desiccation tolerant than S. oryzae. The mortalities of B. bassiana-treated adult Cryptolestes ferrugineus, larval Lasioderma serricorne and larval Oryzaephilus surinamensis were not significantly affected by VPD. These results demonstrate that dry stored-grain conditions are favorable for B. bassiana efficacy.     

Comparative observations on the activity of purethroids against some susceptible and resistant stored products beetles

The activity of six synthetic pyrethroids, allethrin, bioallethrin, resmethrin, bioresmethrin, cismethrin, tetramethrin and also natural pyrethrins, fenitrothion and malathion was examined against susceptible and resistant adult beetles infesting stored products. Cismethrin applied topically was the most active material, alone or synergized, against susceptible Tribolium castaneum, Lasioderma serricorne or Stegobium paniceum.

Solutions in odourless kerosene applied as direct sprays were an average of 6·9 times more active against susceptible T. castaneum than solutions in mineral oil of pyrethrins, bioresmethrin or cismethrin with or without piperonyl butoxide. The factor of synergism was greater when using mineral oil solutions than when using kerosene solutions. It was thought that the more viscous oil slowed penetration of the insecticide giving longer for detoxification, this being inhibited when the synergist was present.

Applied as a dust on wheat, bioresmethrin plus piperonyl butoxide was more active than malathion and less active than fenitrothion against Oryzaephilus surinamensis or susceptible and malathion resistant T. castaneum. Against Sitophilus granarius and susceptible or malathion resistant S. oryzae, synergized bioresmethrin and cismethrin were more active than either malathion or fenitrothion. Malathion resistant S. oryzae was more easily killed by pyrethroids than the susceptible strain. Synergized bioresmethrin was concluded to be the most suitable pyrethroid for controlling stored products beetles, except Lasioderma serricorne and Stegobium paniceum, and was of value against organophosphorus-resistant strains.     

Laboratory evaluation of three novel insecticides inhibiting cuticle formation against some susceptible and resistant stored products beetles

The insecticidal activity of three 1-(2.6-disubstituted-benzoyl)-3-phenylureas was evaluated against a number of susceptible and resistant stored products beetles. The compounds were DU 19111 (1-(2,6-dichlorobenzoyl)-3-(3,4-dichlorophenyl)-urea), PH60-38 (1-(2,6-dichlorobenzoyl)-3-(4-chlorophenyl)-urea), and PH60-40 (1-chlorophenyl)-3-(2,6-difluorobenzoyl)-urea).

PH60-40 was found to be the most effective compound against susceptible strains of Sitophilus granarius, Sitophilus oryzae, Tribolium castaneum and Lasioderma serricorne. All three compounds were ineffective against Stegobium paniceum. A strain of T. castaneum (Kuala Lumpur strain) showing malathion-specific resistance was found to be more susceptible to PH60-40 than its “susceptible” strain. A non-specific resistant strain of T. castaneum (CTC12 strain) showed approximately two times tolerance to PH60-40 compared with the “susceptible” strain.

PH60-40 was shown to have ovicidal properties and also killed young larvae of T. castaneum after short exposure periods. Oviposition was not affected.

Wheat sprayed with an emulsifiable formulation of PH60-40 at 2, 5 or 10 ppm was found to be protected against susceptible T. castaneum, S. granarius and Oryzaephilus surinamensis and against resistant S. oryzae and T. castaneum (Kuala Lumpur strain) following 40 weeks storage at 20°C and 44 weeks storage at 35°C.

Preliminary toxicological data indicates that PH60-40 is of a sufficient order of safety for consideration for grain admixture. The compound is therefore of potential interest as a replacement for the more conventional grain protectants especially in situations where resistance is producing increasing control problems.     

氮气对储烟害虫烟草甲的防治效果

为明确实验室及实仓条件下,氮气对储烟害虫烟草甲4种虫态（幼虫、蛹、成虫、卵）的防治效果,在实验室设置20、25、30℃三个温度,以95%和99%浓度的氮气处理4种虫态的烟草甲,分别在1、2、4、6、8、10、12、14 d后取出,记录试虫死亡情况;在烟仓自然条件下,以99%浓度的氮气处理密闭烟垛中的烟草甲,分别在第9天和第30天取出,记录试虫死亡情况。结果表明,实验室条件下,6个组合处理对各虫态烟草甲均有一定的致死作用,且致死效果随氮气浓度的升高、温度的升高和处理时间的延长而增强。同时,氮气处理对不同虫态烟草甲的防治效果差异显著,对卵和成虫的防治效果高于其他虫态。99%浓度氮气在20、25、30℃条件下处理烟草甲卵4 d,99%浓度氮气在30℃条件下处理烟草甲成虫4 d,校正死亡率即可达100%;实仓条件下,99%浓度氮气处理密闭烟垛9 d,对烟草甲幼虫、蛹、成虫的校正死亡率可达100%。因此,20~30℃条件下,运用氮气杀虫技术可有效防治烟仓中各虫态烟草甲,温度越高、氮气浓度越大效果越好。     

Bacteriological quality assurance (BQA) of mechanically deboned meat (MDM)

Adequacy of bacteriological quality assurance during the commercial production of mechanically deboned meat (MDM) was assessed. Lax standards of hygiene during production were observed, resulting in high numbers of Staphylococcus aureus, viz. 10⁴ to 10⁵ cfu g⁻¹, and severe contamination with Enterobacteriaceae: 10⁵ to 10⁶ cfu g⁻¹. These data indicate that measures of hygiene observed during boning of carcasses and during collection, storage and transport of bones or poultry parts should be markedly tightened, while conditions of refrigerated storage of raw materials and MDM should be improved. Use of bones of poor sensory quality (discoloration, abnormal smell) generally resulted in MDM of inferior bacteriological quality.

Phage typing, biotyping and assessment of enterotoxin production was carried out with 136 St. aureus cultures, isolates from mechanically deboned pork produced at one plant. Fifty-five per cent of the isolates was not typable, 28% was typable with human phages, 8% with bovine phages. The majority of the strains could not be explicitly assigned to any Meyer and/or Hájek and Mar álek types. Applying the simplified system of Devriese to eighteen strains isolated in our investigation, ten were found to belong to the poultry ecovar, one to the bovine ecovar, while seven strains were non-host specific. None of the isolates produced enterotoxins A–E.

Microbiological inspection of end products is recommended as part of an integrated quality assurance system. The following reference values for the final product (maximal colony counts to be expected under GMP conditions expressed as 95th percentile) were calculated: Pig MDM: log₁₀ mesophilic colony count 6·8 and log₁₀ cfu mesophilic Enterobacteriaceae g⁻¹ 4·8; Poultry MDM: log₁₀ mesophilic colony count 6·6 and log₁₀ cfu mesophilic Enterobacteriaceae g⁻¹ 4·7.     

Optimization of Citric Acid Production from a New Strain and Mutant of Aspergillus niger Using Solid State Fermentation

A new strain of Aspergillus niger isolated from soil and its mutant were used for citric acid production from carob under solid-state fermentation conditions. The parental strain produced 30 g/kg citric acid, while the mutant G4, selected after four rounds of gamma ray irradiation, produced 60 g/kg. Maximum citric acid production was obtained after 7 days of incubation, as the acid production was 34 and 64 g/kg for parental and mutant strains, respectively. The addition of 2% methanol increased citric acid production from the parental strain to 42 and the mutant G4 to 65 g/kg. Trace elements, namely Cu, Fe, and Zn, promoted the production of citric acid as the acid production from the parental strain increased to 46 g/kg and for mutant G4 increased to 73 g/kg after their addition. The optimum spore inoculum concentration for acid production was 10⁷ ml^-1, and the optimum pH was 5 for both parental and mutant strains.     

Laboratory evaluation of some additional organophosphorus insecticides against stored-product beetles

The relative susceptibilities of Tribolium confusum Duv. and T. castaneum (Hbst) to seven new organophosphorus insecticides were determined by applying the compounds topically at four dosage rates. SD 8447 (0,0-dimethyl 2-chloro-1-(2,4,5-trichlorophenyl, vinyl phosphate) was more effective than malathion against both species and was evaluated against eight more species of stored-product beetles. It was more toxic than malathion to Rhyzopertha dominica (F.), Lasioderma serricorne (F.), Stegobium paniceum (L.) and Sitophilus zeamais Motsch. but less so against Oryzaephilus surinamensis (L.), O. mercator (Fauv.), Ptinus tectus Boield and Sitophilus granarius (L.). S. zeamais was about eleven times more susceptible to this compound than S. granarius.