类钙粘蛋白对Cry3A毒素杀虫活性的影响

将克隆的黄粉虫类钙粘蛋白基因片段在大肠杆菌中表达纯化,并分析其对Cry3A毒素杀虫活性的影响,从而探讨黄粉虫类钙粘蛋白对Cry3A毒素杀虫活性的增效作用。黄粉虫类钙粘蛋白基因片段在大肠杆菌中表达产物为包涵体,经尿素变性后,用亲和纯化法可得到较纯的重组蛋白;随着类钙粘蛋白片段与Cry3A质量比值的升高,Cry3A毒素对黄粉虫的杀虫活性也逐步提高,当其比值为1时,活性达到最大,提高了2.5倍,而黄粉虫类钙粘蛋白片段对Cry3Am的杀虫活性却没有显著性影响。研究表明,黄粉虫类钙粘蛋白对Cry3A毒素的杀虫活性具有增效作用。     

塔里木灌区膜下滴灌棉花水分生产函数及其效益

以2007—2012年塔里木灌区膜下滴灌田间灌溉试验数据为基础,采用最小二乘法原理,拟合了棉花的水分生产函数模型,分析并计算了棉花最高产量灌溉定额、最佳效益灌溉定额、高效用水灌溉定额,揭示了棉花的水分效应及需水规律。结果表明:塔里木灌区膜下滴灌棉花需水临界期是花铃期和蕾期;产量与耗水量、灌水量均呈良好的二次抛物线关系;合理灌溉定额为3 091~3 464 m~3·hm~(-2),最高产量灌溉定额为3 464 m~3·hm~(-2),高效用水灌溉定额为3 091 m~3·hm~(-2);水资源投入的最佳效益点并非水分利用效率最高点和最高产量点,而是存在于3091~3 464 m~3·hm~(-2)区间;当边际效益等于边际成本时,净收益最大,为24 333.1元·hm~(-2),每立方灌水量净收益7.23元·hm~(-2);现状条件下最佳效益灌溉定额为3 459 m~3·hm~(-2),产量为6 360.7 kg·hm~(-2),与最高产量6 360.8kg·hm~(-2)基本相同,但比最高产量节水5 m~3·hm~(-2),每立方灌水净收益增加0.21元·hm~(-2),水分利用效率提高0.003 kg·m-3。     

杨凌城区雨水资源利用潜力计算及其效益分析

应用径流系数法分析了杨凌示范区城区雨水资源利用潜力.2007年可直接收集利用的雨水总量为123.91万m3,占该年杨凌城区总用水量的28.3%;可处理后回用的雨水总量为367.15万m3,但目前仅有占城区总面积1.98%的绿地利用雨水12.93万m3,其它均未予利用;预计到2020年,以枯水年计算,可直接收集利用的雨水总量为3 233.03万m3;可处理后回用的雨水潜力巨大.并进一步对杨凌城区实施雨水利用后可能产生的经济、社会和生态效益进行了评价分析.     

三种药剂对不同龄期菜青虫敏感性测定

菜青虫(pieriserapaeL.)是十字花科植物的主要害虫之一,至今仍以化学防治为主,使得菜青虫抗药性问题引起关注[1]。70年代对敌百虫、DDVP产生严重抗性,随后相继对有机磷、拟除虫菊酯产生了不同程度的抗药性[2]。国外也曾报道菜青虫对有机磷、拟除虫菊酯产生了抗药性[3～4]。对菜青虫进行抗性监测,明确其对不同药剂的抗性水平,才能为化学防治和延长农药的使用寿命打下理论基础。菜青虫抗性监测,FAO推荐的标准方法是微量点滴法,测定虫态是五龄幼虫。经多年对菜青虫的抗性监测发现五龄幼虫不是测定的最佳龄期,因为五龄幼虫接触药剂后,部分幼…     

新疆降水丰、旱特点及水资源的稳定度

通过205个气象、水文站的25年资料计算,得到新疆年平均降水总量为2425亿立方米,仅占全国降水总量的4%,而面积则占1/6,北疆面积约45万平方公里,年平均降水总量为1150亿立方米,南疆面积约120万平方公里,年平均降水总量1275亿立方米。新疆丰年降水总量为2569亿立方米,枯年降水总量为2340亿立方米。新疆山区年平均降水总量2048亿立方米,占全疆降水总量的84%,平原年平均降水总量为381亿立方米,占全疆降水总量的16%。新疆山区降水变差系数明显小于平原地区,尤其是天山山区其值为0.1—0.2,这与我国南方雨水充沛地区相当。     

水稻黑条矮缩病毒(RBSDV)S3和S10基因组非编码区对翻译的调控作用

 水稻黑条矮缩病毒(Rice black-streaked dwarf virus, RBSDV)基因组含有5′帽子,无3′poly(A)尾巴,且不同基因组片段的5′和3′末端序列均十分保守。本研究以RBSDV S3和S10为对象,分析其非编码区对翻译的调控作用。研究发现S3和S10的5′UTR在有无帽子时均可以正向调控报告基因Fluc的翻译,具备核糖体内部进入位点(IRES)活性,且5′末端的基因组保守序列及邻近序列与IRES活性密切相关;而对应的3′UTR则抑制5′UTR对翻译的正调控效应,其分子基础是5′UTR和3′UTR之间的RNA-RNA互作,且该互作也抑制帽子依赖型翻译的效率。这是首次关于有帽子植物RNA病毒中IRES元件的报道,研究结果对了解植物双链RNA病毒基因组非编码区对翻译的调控作用具有重要科学意义。     

MoHRD3基因参与调控稻瘟病菌的生长发育和致病力

 稻瘟病菌(Magnaporthe oryzae)作为主要的农业病原微生物,其引起的稻瘟病严重威胁着水稻等谷类作物的生产安全。内质网相关蛋白质降解途径(Endoplasmic reticulum-associated protein degradation, ERAD)是生物体应答内质网压力的主要方式之一,其在机体生长发育过程中具有重要作用。而HRD(HMG-CoA reductase degradation)复合物作为ERAD的关键组分,主要由Hrd1、Hrd3、以及凝集素Yos9等蛋白组成,负责内质网中错误折叠蛋白的识别、转运以及泛素化过程,最终由蛋白酶体降解,从而有效缓解内质网压力,保证细胞的正常生理活动。有研究表明,Hrd3属于单次跨膜蛋白,在内质网腔中与Hrd1、Yos9相结合,负责底物的识别并起着稳定Hrd1的作用。目前Hrd3在稻瘟病菌中的生物学功能尚不清楚。本研究通过基因敲除及互补试验获得了稻瘟病菌的ΔMohrd3突变体和ΔMohrd3-C回补菌株,并以野生型为对照,对突变体的生物学表型进行了分析。结果显示,ΔMohrd3突变体的生长速率、产孢量明显下降;对大麦和水稻的致病力显著减弱。进一步胁迫试验表明,MoHRD3的缺失导致稻瘟病菌对外界盐胁迫、渗透压胁迫的耐受性增强,对内质网胁迫耐受性减弱,而对细胞壁胁迫无明显变化。同时,MoHRD3基因的缺失激活了未折叠蛋白响应途径(Unfolded protein response, UPR)。上述结果表明,MoHRD3参与调控稻瘟病菌的营养生长、无性繁殖、致病及对不同环境胁迫的响应过程。     

Triphenyl derivatives of group IV elements as inhibitors of growth and digestive enzymes of Tribolium castaneum larvae

The potency of triphenyl derivatives of group IV elements in inhibiting the growth of first and fourth instar Tribolium castaneum larvae is much greater for Ph₃SnCl and Ph₃PbCl than for Ph₃GeCl, Ph₃SiOH, and Ph₃CCl. Pupated larvae emerge normally, showing that the pupal stage is not affected. The larval growth retardation may result from an antifeeding effect involving digestive enzyme inhibition. Ph₃SnCl and Ph₃PbCl at 500 μmol/kg of diet completely inhibit larval growth (fourth instar larvae) and provide a reduction of 56–59, 29–33, and 2–15% in the in vivo activity of invertase, amylase, and protease, respectively. Under these conditions Ph₃GeCl, Ph₃SiOH, and Ph₃CCl are essentially inactive. High concentrations (5 × 10^?4 and 2 × 10^?3M) of Ph₃SnCl and Ph₃GeCl acting in vitro strongly inhibit invertase, amylase, and protease activities, whereas Ph₃PbCl is moderately inhibitory and Ph₃SiOH and Ph₃CCl are inactive. When both in vivo and in vitro findings are considered, Ph₃SnCl is the most potent inhibitor of larval digestive enzymes.     

MoHRD3基因参与调控稻瘟病菌的生长发育和致病力

 稻瘟病菌(Magnaporthe oryzae)作为主要的农业病原微生物,其引起的稻瘟病严重威胁着水稻等谷类作物的生产安全。内质网相关蛋白质降解途径(Endoplasmic reticulum-associated protein degradation, ERAD)是生物体应答内质网压力的主要方式之一,其在机体生长发育过程中具有重要作用。而HRD(HMG-CoA reductase degradation)复合物作为ERAD的关键组分,主要由Hrd1、Hrd3、以及凝集素Yos9等蛋白组成,负责内质网中错误折叠蛋白的识别、转运以及泛素化过程,最终由蛋白酶体降解,从而有效缓解内质网压力,保证细胞的正常生理活动。有研究表明,Hrd3属于单次跨膜蛋白,在内质网腔中与Hrd1、Yos9相结合,负责底物的识别并起着稳定Hrd1的作用。目前Hrd3在稻瘟病菌中的生物学功能尚不清楚。本研究通过基因敲除及互补试验获得了稻瘟病菌的ΔMohrd3突变体和ΔMohrd3-C回补菌株,并以野生型为对照,对突变体的生物学表型进行了分析。结果显示,ΔMohrd3突变体的生长速率、产孢量明显下降;对大麦和水稻的致病力显著减弱。进一步胁迫试验表明,MoHRD3的缺失导致稻瘟病菌对外界盐胁迫、渗透压胁迫的耐受性增强,对内质网胁迫耐受性减弱,而对细胞壁胁迫无明显变化。同时,MoHRD3基因的缺失激活了未折叠蛋白响应途径(Unfolded protein response, UPR)。上述结果表明,MoHRD3参与调控稻瘟病菌的营养生长、无性繁殖、致病及对不同环境胁迫的响应过程。     

Conversion of α-pinene to α-pinene oxide by rat liver and the bark beetle Dendroctonus terebrans microsomal fractions

The metabolism of α-pinene, a major monoterpene in Pinus spp. in the United States, has been examined utilizing microsomal fractions from larval and adult Dendroctonus terebrans and rat liver. Under hydroxylating conditions, both insect and rat liver microsomes convert α-pinene into α-pinene oxide and several other undentified products. α-Pinene oxide was identified by mass spectrometry. α-Pinene is an inducer of cytochrome P-450 in rat liver microsomes and its effect on the pattern of α-pinene metabolism is very similar to β-naphthoflavone. No increase in cytochrome P-450 was observed when insects were treated with α-pinene; however, the quantity of α-pinene metabolic products was increased by α-pinene pretreatment. The role of cytochrome P-450 linked reactions in the production of insect pheromones via the α-pinene epoxide intermediate is discussed.     

水稻干尖线虫14-3-3(Ab-14-3-3-a)基因克隆与功能分析

水稻干尖线虫是水稻上重要的寄生线虫,严重危害水稻安全生产。14-3-3蛋白调控生物体的细胞代谢、生长发育和逆境适应等一系列生物过程。本研究通过c DNA末端快速扩增技术(rapid amplification of c DNA ends,RACE)分离获得了一个水稻干尖线虫(Aphelenchoides besseyi)14-3-3基因,命名为Ab-14-3-3-a。Ab-14-3-3-a全长c DNA序列含有59 bp的5'非翻译区(UTR)、编码251个氨基酸756 bp的开放阅读框。Ab-14-3-3-a DNA序列包含4个外显子和3个内含子。Ab-14-3-3-a蛋白与其他植物寄生线虫14-3-3蛋白氨基酸序列高度相似,系统发育树显示与植物寄生线虫位于同一进化分支。原位杂交显示Ab-14-3-3-a特异定位于成虫的背食道腺细胞中,表明其在线虫取食和寄生过程中发挥潜在功能。qRT-PCR显示,Ab-14-3-3-a在水稻干尖线虫各个龄期均表达,其中在成虫表达水平最高,而在发育过程中幼虫表达水平最低。当线虫取食不同寄主时,Ab-14-3-3-a的表达水平具有差异性,线虫取食感病水稻早期,Ab-14-3-3-a表达水平上升1.5倍,而取食灰葡萄孢(Botrytis cinerea)时Ab-14-3-3-a表达可提高数百倍。利用体外RNA干扰技术将Ab-14-3-3-a的表达进行有效抑制,结果显著影响了线虫的产卵、成虫发育以及线虫种群数量。综上,Ab-14-3-3-a参与调控水稻干尖线虫的取食行为和发育进程。本研究相关结果有助于拓展植物寄生线虫14-3-3蛋白功能,为深入研究线虫与植物互作机制提供了理论依据。     

内蒙古黄土高原区降水规律与集雨利用潜力分析

在黄土高原干旱少雨,地下水埋深较深的地区,通过建立水窖集雨供人畜饮用和作物补充灌溉具有重要意义。本研究利用沙圪堵镇的准格尔旗气象站1959—2000年气象资料,进行降水规律分析。结果表明,位于内蒙古黄土高原区的准格尔旗年均降水量为392.1mm,最大年降水量为635.5mm,最小降水量仅为142.5mm。年降水量在500mm以上的保证率为19%,接近五年一遇,年降水量400mm以上的保证率为44%,可基本上满足短季耐旱作物的生长之需;降水量在300mm之下的频率为21%,不能满足作物生长对水分的需求。有1/3的年份年降水量300—400mm之间,作物生长所需水分亏缺的部分,需要适当补灌。由于4—5月作物播种和苗期降水量少,存在生长障碍,如能在前一年集雨次年春天补充灌溉将有利于全苗和增产。对于10mm以上的降水,保证率80%以上的降水量仅为135mm,保证率60%的降水量为200mm。中雨雨量为达到300mm的保证率只有30%。对于大雨过程,总降水量200mm只有15%的可能性,100mm以上的保证率为60%。如果降水10mm以上才能集到雨水,100m2的集雨面,只有60%的年份产水量大于20方。不同集雨面的集流效益不同,在建立集雨水窖时,要根据水窖体积和集雨面材料的集流效率,合理确定集雨面,保证80%以上的年份达到满意的集雨效果。另外,根据降水规律可利用自然地面进行田间集雨,利用土壤库容保存降水供作物生产之用。     

A new quantitative real-time PCR assay for Rhizoctonia solani AG3-PT and the detection of AGs of Rhizoctonia solani associated with potato in soil and tuber samples in Great Britain

Rhizoctonia solani is an important pathogen of potatoes causing stem canker and black scurf. The fungus is a species complex comprised of 13 known anastomosis groups (AGs). AG3-PT is the anastomosis group frequently associated with disease in potatoes. A real-time PCR assay was designed to the rDNA ITS region of AG3-PT isolates to enable the pathogen to be detected directly in tuber and soil samples. The resulting assay was highly specific for AG3-PT, and did not amplify DNA from isolates from other AGs or subgroups of AG3. Using a bulk DNA extraction method capable of extracting from up to 250 g of soil, the assay could detect one individual sclerotium of AG3-PT (weighing 200 μg) in 250 g of soil. The AG3-PT assay was used, with assays for AG2-1, AG5 and AG8 to determine the prevalence of those AGs in UK potato soils and tubers. AG2-1 and AG3-PT were the predominant groups in tubers and soils, although AG3-PT was more frequently isolated from tubers, highlighting its importance as a potato pathogen. AG3-PT was also detected in more than half of the tuber samples tested suggesting the importance of seed borne inoculum.     

Cf-2/Rcr3pim番茄品系对南方根结线虫的抗性测定

Cf-2/Rcr3~(pim)基因型番茄不仅能够抵御番茄叶霉菌的侵染,而且对马铃薯金线虫的寄生也有一定的抑制效果。为挖掘根结线虫的新抗性资源,本研究采用室内人工接种法测定了Cf-0/Rcr3~(pim)、Cf-2/Rcr3-3和Cf-2/Rcr3~(pim)基因型番茄品系对南方根结线虫的抗感性。抗性评价结果显示,Cf-0/Rcr3~(pim)品系对南方根结线虫表现高感,Cf-2/Rcr3-3品系为中感,而Cf-2/Rcr3~(pim)品系则为感病。与Cf-0/Rcr3~(pim)和Cf-2/Rcr3-3基因型相比,Cf-2/Rcr3~(pim)基因型番茄品系虽然对南方根结线虫侵染的敏感性略低,但是不能阻止线虫在根系上的大量繁殖,不适于根结线虫的防控应用。     

Synthesis and bioactivity of some fluorine-containing benzoyl arylureas. Part I: Insecticidal-acaricidal products in which the aryl group bears a trifluoromethyl-substituted alkyl or alkenyl side chain

This paper reports the synthesis and the biological activity of benzoyl arylureas in which the aryl group bears a trifluoromethyl-substitiited alkyl or alkenyl side chain, R. The activity of these compounds has been evaluated on larvae of S. littoralis, A. aegypti, L. decemlineata and on the eggs of T. urticae. In general: (1) the optimum insecticidal activities are achieved when the substituents on the benzoyl moiety, R₁, and R₂, are 2,6-difluoro, the substituents on the aryl moiety, R₃, are 3,5-dichloro and R₁, is 4-(? CH?C(CI)CF₃); (2) the best acaricidal activity is shown when R₁, is 2-CI, R₂, and R₃, are hydrogen atoms and R₁, is 4-(? CH₂CH₂CH(CI)CF₃); (3) the best overall activity is displayed when R₁, is 2-CI, R₂ is hydrogen, R₃ is 3-chloro and R₁ is 4-(? CH₂CH₂CF₃).     

柑橘黄龙病病原DNA微量提取方法比较

对比分析了3种黄龙病病原DNA微量提取方法,方法1和方法2分别采用Sandrine等人和Hung等人的黄龙病病原DNA提取方法,但取样量分别由100mg和250mg减少为20mg和10mg;方法3采用周常勇等人的微量核酸提取方法,取样量为10mg.实验结果表明:方法1提取的病原DNA浓度低、杂质多,PCR效果差;方法2提取的病原DNA浓度较高、杂质少,PCR效果好,但提取周期较长,不适合大批量样品的PCR快速检测;方法3提取的病原DNA浓度较高、杂质少,PCR效果好,且提取速度快,适宜大批量样品的PCR快速检测.     

Partial Nucleotide Sequence and Genome Organization of a Canadian Isolate of Little cherry virus and Development of an Enzyme-Linked Immunosorbent Assay-Based Diagnostic Test

ABSTRACT Approximately 12.4 kb of the genome of a mealybug-transmissible, North American isolate of Little cherry virus (LChV-3, previously designated LChV-LC5) has been cloned and sequenced. The sequenced portion of the genome contains 10 open reading frames (ORFs) and, based on sequence comparisons, encodes a putative RNA helicase (HEL), RNA-dependent RNA polymerase (POL), two coat proteins (CPs), a homologue of HSP70, a 53K protein (p53) that is similar to an equivalent-size protein in other closteroviruses, and a 22K (p22) protein of unknown function. The genome also potentially encodes two small proteins (p5 and p6), one of which is similar to the small hydrophobic proteins of other closteroviruses. Phylogenetic analyses utilizing sequences of the HEL, POL, and HSP70 homologue suggest that LChV-3 is most similar to other mealybug-transmitted closteroviruses. Further comparisons between LChV-3 and a 4.7-kb region of the recently described Little cherry virus-2 (LChV-2) reveals 77% nucleotide sequence identity. Based on this low sequence identity, we propose that LChV-3 be considered a separate species, designated LChV-3. Unexpectedly, the LChV-3 CP duplicate ORF was found to lie upstream of the HSP70 ORF; therefore, the genome organization of LChV-3 is distinct from that of other closteroviruses. Polyclonal antiserum raised to bacterially expressed LChV-3 CP was useful for detection of LChV-diseased trees in the cherry-growing districts of British Columbia, Canada.     

氯氰菊酯四对异构体在HPLC紫外检测器上响应值的比较

用高效液相色谱法紫外检测器分别测定氯氰菊酯中的高顺式异构体（１Ｒ，３Ｒ，１Ｓ，３Ｓ）－顺式（ＳＲ）高反式异构体（１Ｒ，３Ｓ，１Ｓ，３Ｒ）－反式（ＳＲ）；高顺，高反式混合体以及高顺，高反，低顺，低反混合体（简称四对混合体）响应值，实验分别采用两种内标物做内标法测定，结果表明四对异构体对紫外检测器器的响应值是一致的。     

Fumigation as a Means of Eradicating Colorado Beetle in Imports of Potatoes, Grain and Timber

Colorado beetle is not indigenous to the United Kingdom, but is often found in imported produce and is a serious pest of potato crops. The efficacy at 10°C of five fumigants was tested against diapausing beetles in the laboratory. Phosphine was the most effective giving 100 % kill in tests with a concentration time product of 6.7 g.h/m³; 100 % kill was also achieved in tests with: methyl bromide at 166 g.h/m³; carbon tetrachloride at 4000 g.h/m3; ethylene dichloride at 6240 g.h/m³; and 1,1,1-trichloroethane at 11600 g.h/m³. A set of practical dosage schedules is given.