猪的霉菌毒素中毒及防制措施

介绍了玉米霉变的霉菌种类和毒素种类,猪霉菌毒素的中毒症状。提出了切实可行的防制猪霉菌毒素中毒的措施,探讨了猪霉菌毒素中毒的原因及诱发的其它合并症。     

C肉毒杀鼠素在高寒草甸地区灭鼠技术中的应用

综述C肉毒杀鼠素草原灭鼠应用技术,充分肯定了C肉毒杀鼠素毒力强、适口性好、对非靶动物毒性低、作用缓慢、无二次中毒、易降解和适合规模灭鼠的特点,为鼠害防治提供了新的思路。     

Secretion of Natural and Synthetic Toxic Compounds from Filamentous Fungi by Membrane Transporters of the ATP-binding Cassette and Major Facilitator Superfamily

This review provides an overview of members of the ATP-binding cassette (ABC) and major facilitator superfamily (MFS) of transporters identified in filamentous fungi. The most common function of these membrane proteins is to provide protection against natural toxic compounds present in the environment of fungi, such as antibiotics produced by other microorganisms. In plant pathogenic fungi, these transporters can also be an important determinant of virulence on host plants by providing protection against plant defence compounds or mediating the secretion of host-specific toxins. Furthermore, they play a critical role in determining base-line sensitivity to fungicides and other antimycotic agents. Overexpression of some of these transporters can lead to the development of resistance to chemically-unrelated compounds, a phenomenon described as multidrug resistance (MDR). This has been observed in a variety of organisms and can impose a serious threat to the effective control of pathogenic fungi.     

Bt对小地考虑呼吸作用的影响

利用红外CO2分析仪测定小地老虎幼虫呼吸节律的变化结果显示：小地老虎幼虫呼吸节律属于不规则波动型，取食含Bt烟叶的幼虫呼出的CO2量显著低于对照组，且呼吸节律的波动性也明显增大，说明小地考虑幼虫取食Bt后，呼吸代谢受到一定干扰，出现呼吸水平降低及代谢紊乱现象。     

苏云金芽孢杆菌cry基因在大肠杆菌中表达产物和生物活性

研究了几种Bt cry基因于大肠杆菌(Escherichia coli)中表达产物在pH 10.0的50mmol/L碳酸钠和20mmol/L乙醇胺溶解液中的溶解性 ,发现同样的Cry蛋白在碳酸钠中的溶解度大于乙醇胺。通过胰蛋白酶消化 ,明确Cry1Ca7、Cry1Ia8酶解产物为 38kD多肽 ;Cry1Ie1、Cry1Cb2、Cry2Ab4酶解产物为 41kD多肽 ;Cry1Ac酶解产物为60kD多肽。采用FPLC层析方法对 6种原毒素及其酶解后得到的毒素多肽进行了分离纯化 ,比较了原毒素和毒素的杀虫活性的差异。其结果表明 ,Cry1Ac的原毒素和毒素对棉铃虫初孵幼虫的校正死亡率均为 100% ,Cry2Ab4的原毒素的毒力高于其酶解毒素。     

昆虫氨肽酶N的研究进展

氨肽酶N(aminopeptidase N,APN)是一种偏好水解蛋白或寡肽N端中性氨基酸的酶,广泛分布于动植物中。在昆虫中,APN主要分布于中肠刷状缘膜上,涉及食物蛋白的消化以及Bt毒素对靶标害虫的作用。从APN的结构特征和分类地位、APN的分离纯化及其酶活性位点与结合位点的相关性、APN同工酶的区分特征及系统发育关系、APN同工酶的基因功能、不同APN同工酶在昆虫体内的分布及表达量、APN基因功能最新研究方法和结果以及APN与昆虫抗药性的关系等方面概述了昆虫APN的最新研究进展。鉴于昆虫体内受体的多样性、复杂性及当前研究手段的局限性,对APN功能的全面了解还有赖于研究方法的改进和提高而逐步深入。     

Identification of Alternaria spp. on wheat by pathogenicity assays and sequencing

The pathogenicity of Alternaria spp. isolated from wheat leaves collected in regions where alternaria leaf blight has been reported was compared with that of IMI reference isolates of A. triticina and A. alternata using two durum and two bread wheat genotypes. To identify isolates putatively corresponding to A. triticina , morphological and DNA sequence analyses based on ribosomal DNA from the internal transcribed spacer (ITS) region (ITS1, 5·8S rRNA gene, ITS2) and toxicity bioassays of culture filtrate were combined. Glasshouse inoculations provided reliable information to assess the pathogenicity of A. triticina isolates on wheat. Alternaria leaf blight symptoms were produced by the A. triticina isolates only on durum wheat cv. Bansi, while A. alternata , A. tenuissima and A. arborescens isolates were found to be nonpathogenic on the wheat cultivars tested. Alternaria triticina isolates were distinguished from other Alternaria species by Simmons and Roberts' sporulation pattern 6 and two to three conidia per sporulation unit associated with primary conidia bearing long (> 7  µ m) apical secondary conidiophores. Phylogenetic analysis also proved effective at discriminating wheat-pathogenic A. triticina from other nonpathogenic Alternaria species. Alternaria triticina isolates yielded longer ITS sequences than A. alternata , A. tenuissima and A. arborescens isolates, leading to clear-cut differences as visualized with agarose gel electrophoresis. Additionally, only culture filtrates of A. triticina isolates caused nonspecific necrotic lesions on leaves of 3-week-old wheat plants.     

转Bt基因棉种植前后3个棉铃虫种群对4种杀虫剂的抗性变化

分别于1990年、1992年、2001年和2005年从山东泰安、山东夏津和湖北天门采集3个棉铃虫H elicoverpa arm igera种群,采用点滴法测定了4种杀虫剂对其的毒力,以监测各种群的抗药性变化趋势。结果表明:19901992年3个种群棉铃虫对氰戊菊酯的抗性增长迅速(13.256.1倍);19922001年抗性增长速度有所减缓(3.111.0倍);20012005年抗性水平降低。3个种群棉铃虫对灭多威和辛硫磷的抗性变化趋势与氰戊菊酯的基本相似,但抗性水平较低;对硫丹则均一直处于敏感水平。引起抗药性变化的原因主要与各类药剂的使用频率和转B t基因抗虫棉的大面积推广有关。     

苏云金芽孢杆菌营养期杀虫蛋白Vips研究进展

苏云金芽孢杆菌Bt营养期杀虫蛋白Vips主要分为Vip1、Vip2和Vip33种。Vip1和Vip2构成二元毒素,对叶甲科昆虫具有特异杀虫活性。Vip3对鳞翅目昆虫具有广谱杀虫活性,该蛋白广泛存在于Bt中,与已知杀虫晶体蛋白ICPs没有序列相似性。Vip3通过诱发细胞凋亡,最终导致昆虫死亡,这与Btδ-内毒素的作用机理完全不同,Vips的发现对于Bt的进一步开发利用具有重要意义。本文主要对营养期杀虫蛋白Vips的分布、特性、作用机制及应用等进行报道。     

新疆南部转基因棉区棉铃虫种群长期动态研究

（Bacillus thuringiensis）基因抗虫棉在新疆南部推广已超过10 a,为探索Bt棉大面积种植对棉铃虫（Helicoverpa armigera）种群动态的影响,于1999-2010年使用诱虫灯监测了Bt棉大面积种植区域（麦盖提）和非Bt棉大面积种植区域（阿瓦提）棉铃虫的种群动态。结果表明：新疆南部地区20世纪90年代末发生棉铃虫害较重,2000-2004年种群数量保持较高水平;自2005年Bt棉大面积推广以后,Bt棉区棉铃虫的种群数量显著下降,棉铃虫种群数量随Bt棉种植比例的上升而下降（P<0.05）;]随着Bt棉大面积推广年数的增加,Bt棉区棉铃虫各代种群数量均逐渐下降,第二代种群数量和高峰期蛾量下降速率均较越冬代和第一代快,且第二代棉铃虫种群相对丰富度也逐渐下降。因此,新疆地区Bt棉的大面积种植能较好地控制棉铃虫的种群数量,而且对第二代棉铃虫种群的控制效果最好。