苏云金芽孢杆菌HBF-1菌株防治金龟科幼虫的效果评价

以我国筛选出的对金龟科幼虫具有杀虫活性的HBF-1菌株为供试菌株，采用菌悬液与含有土豆丝的土壤混合饲喂幼虫的方法，测定了HBF-1菌株孢晶粉剂对华北地区主要金龟子幼虫的毒力，其敏感性依次为四纹丽金龟Popillia quadriguttata、黄褐丽金龟Anomala exoleta、蒙古丽全龟A．mongolica、铜绿丽金龟A．corpulenta和苹毛丽金龟Proagopertha lucidula，LC50为3．104、18．987、30．924、34．713和55．995μg／s土。HBF-1菌株悬浮剂防治花生田金龟子幼虫的田间小区试验结果表明，50倍液的虫口减退率为71．4％～75．4％，保果效果为58．7％～72．9％。在花生产量比较试验中，HBF-1菌株悬浮剂50倍液处理区比空白对照区的产量增加363．0—903．0kg／hm^2。HBF-1菌株悬浮剂施入草坪后可免受阳光中紫外线的照射，杀虫活性保持较长时间；经调查，HBF-1制剂在土壤中经过120天后仍保持杀虫活性。     

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。     

苏云金素与苏云金杆菌芽孢晶体混剂对小菜蛾的增效作用

将苏云金素和苏云金杆菌的孢晶制剂分别作为单一制剂，用混和饲料感染法在室内测定苏云金素分别与苏云金杆菌ＨＤ－１、ＣＴ－４３、８１－６、ＷＰ－２等４个菌株孢晶制剂的混剂对小菜蛾幼虫的协同作用。按Ｓｕｎ－Ｊｏｈｎｓｏｎ毒力指数法计算结果表明，苏云金素对所有供试菌的孢晶制剂都有增效作用，共毒系数从１２７．４３至４１５．６２不等。当混剂以芽孢晶体为主要活性组分，苏云金素占全部活性组分的１６．７％情况下增效作     

新杀虫菌“018”防治棉红铃虫

1977年我们获得一株对棉红铃虫毒杀作用很强的芽孢杆菌,代号“018”。该菌纯孢晶(芽孢和蛋白质晶体毒素)混合物对越冬红铃虫的致死中浓度(LC50)为0.01413mg/m1,0.1—0.5亿/ml菌悬液的校正死亡率高达90％以上。经1977、1978两年田间试验:“018”菌的防治效果明显高于DDT和1605。经中国科学院武汉病毒研究所虫菌组鉴定:认为“018”菌是我国首次发现的苏云金杆菌英里逊变种(Bacillus thuringiensis Var.     

东北地区高毒力苏云金芽孢杆菌HB-3菌株生物学特性研究

从自然死亡的玉米螟幼虫体内分离获得一株对玉米螟高毒的苏云金芽孢杆菌,编号为HB-3。该菌株产生菱形和方形两种晶体蛋白。纯化晶体及孢晶混合物的毒力测定结果表明,该菌株对玉米螟具有较高毒力,LC₅₀分别为5.82μg/mL和5.94μg/mL,对尖音库蚊也有一定毒力,LC₅₀分别为16.59μg/mL和17.50μg/mL。生理生化特性研究结果表明,HB-3与已知的蜡螟亚种(Bacillus thuringiensissubsp.galleriae)基本一致,血清型为H5ab。晶体蛋白的SDS-PAGE分析表明,HB-3菌株晶体蛋白至少由分子量为133 kDa、65 kDa4、5 kDa和23 kDa的4种多肽组成。     

球形芽直菌杀蚊毒素的作用方式和蚊虫的抗性特征

球形芽孢杆菌是一种对蚊幼虫有毒杀作用的好气芽孢杆菌。高毒力菌株在孢形成过程中能产生有５１．４和４１．９ｋＤａ蛋白组成的伴孢晶体。蚊幼虫取食芽孢／晶体混合物后,晶体蛋白被降解形成活性蛋白而结合到中肠上皮细胞的特异性结合位点上,最后导致蚊幼死亡;低毒力菌和部分高毒力菌株在其营养体生长阶段可产生可溶性的１００、３０．５和３８．５ｋＤａ的Ｍｔｘ毒素。该毒晶体毒素其它杀虫纱无同源性,其杀蚊人艇机理不祥。在实     

苏云金杆菌高毒力菌株4．0718的快速选育

从湖南省不同生态区域的旱作地，果园和稻园采集的858份土样中，分离筛选出苏云金杆菌30株。选取一株具典型苏云金杆菌菌落特征和较高杀虫毒力的菌株701^2c为出发菌株，经紫外线和两次亚硝基胍的交替复合诱变，显微涂片染色镜检，发现菌体的伴孢晶体的形状、大小、数量及芽孢与伴孢晶体的比例与杀虫菌株4．0718。该突变株杀虫毒力与原始菌株相比提高了7．5倍，在6、12和24h内供试小菜蛾三龄幼虫死亡率分别高达20％、97％和100％。此菌株的高效速效杀虫毒力经连续10代培养能稳定遗传。     

苏云金杆菌HBF-1菌株在土壤中毒蛋白含量的ELISA检测

以苏云金芽孢杆菌HBF-1菌株中分离纯化的高特异性杀虫蛋白作为抗原，免疫新西兰白兔制备出多克隆抗体，其效价可达到16000。应用制备的特异性抗体建立了间接酶联免疫吸附测定法（ELISA），检测不同土壤样品中Bt毒蛋白含量。初步结果表明，该方法能够检测土壤中Bt毒蛋白的含量，因土壤理化特性及组成成分的不同，检测到的毒蛋白含量也略有不同，河沙中的蛋白检测量最低，只有12．53％；另一种沙壤混合物中检测量达到76.16％。     

夜蛾科昆虫高毒力苏云金杆菌菌株的分离和筛选

从山东省采集的750份土样中分离出苏云金芽孢杆菌菌株57株,这些菌株的晶体形态主要有菱形、圆形等。以夜蛾科害虫粘虫和甜菜夜蛾初孵幼虫为试虫,通过生测筛选出一株高毒力菌株QCL-1。菌株QCL-1对甜菜夜蛾的毒力显著高于标准菌株HD-1,对粘虫的毒力与HD-1相当。     

苏云金芽孢杆菌对松材线虫的杀线活性

在室内条件下,测定了17株苏云金芽孢杆菌Bacillus thuringiensis伴孢晶体蛋白对松材线虫Bursaphelenchus xylophilus的杀线活性。通过初筛,发现菌株020、RBT-200701的伴孢晶体蛋白对松材线虫有明显毒杀作用。在测试的浓度范围内（菌株020为6.37-203.9μg/ml;RBT-200701为13.7-438.8μg/ml）,菌株对松材线虫的校正死亡率随其浓度增大而提高;随时间延长杀虫效果提高。020菌株晶体蛋白24h、48h时对松材线虫的LC50、LC95分别为183.20、408.20μg/ml和80.132、25.29μg/ml;RBT-200701菌株伴孢晶体蛋白24、48h时对松材线虫的LC50、LC95分别为368.00、868.00μg/ml和82.73、382.73μg/ml。SDS-PAGE分析发现这2个菌株晶体蛋白的蛋白图谱不同。     

对氯苯丙酮肟衍生物的合成及其生物活性

为寻找新型结构的农药先导化合物,采用1-对氯苯基-3-氯-1-丙酮为原料,合成了14个结构新颖的对氯苯丙酮肟衍生物,其化学结构经1H核磁共振和元素分析确证。初步的生物活性试验结果表明,该类化合物具有一定的杀虫和除草活性,其中化合物 Ⅴi、Ⅴe和Ⅴh 在 50 mg/L浓度下对淡色库蚊Culex pipiens pallens的致死率达到100%。     

Synthesis and herbicidal activity of isoxazole-substituted 1-aminoethylphosphonates and 1-hydroxyethylphosphonates

Isoxazole-substituted 1-aminoethyl- and 1-hydroxyethyiphosphonates were synthesized by a multi-step procedure and were screened for herbicidal activity against Lepidium sativum L. and Cucumis sativus L. All the synthesized compounds exhibited notable herbicidal activity.     

Synthesis and biological evaluation of [1-(1H-1,2,4-triazol-1-yl)alkyl]-1-silacyclopentanes

A series of 1-aryl-1-(1H-1,2,4-triazol-1-yl)alkyl-1-silacyclopentanes has been synthesized by four-step reactions starting from 1-chloroalkyltrichlorosilane and tested for fungicidal activities in vitro for ten fungi and in vivo for four fungi occurring in rice, cucumber, tomato etc. Biological activities of the title compounds are strongly dependent upon the p-substituent on the phenyl group in the following order: F>Cl>Ph>OEt>H. Especially, 1-p-fluorophenyl-1-[1-(1H-1,2,4-triazol-1-yl)alkyl]-1-silacyclopentanes (alkyl=methyl or ethyl) showed significant fungicidal activity with a broad spectrum comparable to flusilazole in in-vivo assay. © 1998 SCI.     

Striga asiatica seed conditioning and 1-aminocyclopropane-1-carboxylate oxidase activity

Conditioned seeds of Striga asiatica (L.) Kuntze release ethylene, which elicits germination. We investigated the activity of 1-aminocyclopropane-1-carboxylate (ACC) oxidase and respiration during conditioning. Seeds incubated in vivo with ACC, the substrate for ACC oxidase, produced negligible ethylene at the beginning of conditioning or if they were dormant (i.e. would not germinate after conditioning and treatment with stimulant). Non-dormant seeds produced 3000 ηL of ethylene/600 seeds/24 h after 12 days of conditioning. In vitro ACC oxidase activity at day 0 of conditioning produced 500 ηL of ethylene/μg protein/h and 8000 ηL of ethylene/μg protein/h after 12 days of conditioning. Incubation of seeds in strigol before protein extraction did not enhance enzyme activity. Seeds released 4000 μL/L CO₂ in the first 24 h of conditioning, with the rate increasing to 15 000 μL/L/24 h on day 4 and then remaining roughly unchanged. Maximum in vitro activity of ACC oxidase required ACC, catalase, O₂, Fe²⁺, ascorbate and CO₂. In vivo activity of ACC oxidase required ACC and/or germination stimulant(s), suggesting that stimulants may be involved in providing substrates for the ACC oxidase. No difference was observed in the separation of extracted proteins, which suggests that ACC oxidase is activated during conditioning, perhaps as a result of changes in co-factor concentration. Application of these findings to Striga control is discussed.     

1-取代苯胺基- 4,4-二甲基-2-(1H-1,2,4-三唑-1-基)-1-戊烯-3-酮的合成及其生物活性

为寻找高活性的烯基三唑类杀菌剂,利用1-二甲氨基-4,4-二甲基-2-(1H-1,2,4-三唑-1-基)-1-戊烯-3-酮与取代苯胺进行亲核取代反应,合成了一系列新型1-取代苯胺基-4,4-二甲基-2-(1H-1,2,4-三唑-1-基)-1-戊烯-3-酮化合物,其结构经元素分析、核磁共振氢谱确认。由1H NMR分析结果推测该类化合物E式构型为优势产物。初步生物活性测试结果表明,化合物 1n (取代基R=3-OCH3)在50 μg/mL浓度下对葡萄白腐菌Coniothyrium diplodiella、黄瓜黑星菌Cladosporium cucumerinum等的抑制率均达到100%;在10 μg/mL浓度下对促进黄瓜子叶生根的活性达到155.2%。     

Dominance variation across six herbicides of the Arabidopsis thaliana csr1-1 and csr1-2 resistance alleles

Dominance of a resistance trait can be defined as a measure of the relative position of the phenotype of the heterozygote RS compared with the phenotype of the two corresponding homozygotes, SS and RR. This parameter has been shown to have primary importance in the dynamics of pesticide resistance evolution. Literature on insecticide resistance suggests that dominance levels in the presence of insecticide vary greatly from completely recessive to completely dominant. With insecticides, both the chemical applied and the dosages used have been demonstrated to affect the dominance. By contrast, almost all herbicide resistances have been found to be inherited as partially to totally dominant traits. This discrepancy between weeds and insects may partly result from the methodologies applied to measure the dominance, ie a single dose for herbicide versus several doses for insecticide. Using two well-known resistances (csr1-1 and csr1-2) to acetolactate synthase (ALS) inhibitors in Arabidopsis thaliana (L) Heynh (mouse-ear cress), we used several herbicide doses to determine the dominance level to six ALS-inhibiting herbicides. The dominance level in the presence of herbicide varied from completely dominant to completely recessive, depending on the resistance allele and the herbicide tested. The dominance of the csr1-1 and csr1-2 resistance alleles ranged from 0 (completely recessive) to 1.1 (dominant) and from 0 to 0.3 (partially dominant), respectively. The recessivity of some resistance alleles in the presence of herbicide could lead to the development of improved resistance management in order to delay or avoid herbicide resistance evolution, especially in the control of outcrossing weed species.     

PP 1/297 (1) Thrips on stone fruits and citrus

Specific scope

This Standard describes the conduct of trials for the efficacy evaluation of foliar insecticides against thrips on citrus and stone fruits.

Specific approval and amendment

First approved in 2017‐09.