共查询到20条相似文献,搜索用时 15 毫秒
1.
Toxicity evaluation of botanical insecticides and their mixture against the spiraling whitefly,Aleurodicus dispersus
下载免费PDF全文
![点击此处可从《生物安全学报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
【背景】螺旋粉虱是新入侵海南省的严重为害经济作物及园林苗木的害虫。目前,植物源杀虫剂因具有高效和环境友好等特性而被广泛用于害虫防治中。【方法】采用喷雾法和药膜接触法分别测定了9种植物性杀虫剂对螺旋粉虱的毒力。【结果】在供试的9种植物性杀虫剂中,除虫菊素和鱼藤酮对螺旋粉虱成虫的毒力最强,24h的LC50分别为2.56和34.15mg·L-1;印楝素和苦瓜叶提取物的毒力次之,LC50分别为158.36和311.02mg·L-1。除虫菊素对螺旋粉虱若虫和卵也有一定的触杀作用,LC50分别为61.42和77.39mg·L-1。将印楝素和鱼藤酮分别与除虫菊素以1:1的比例混合,对螺旋粉虱成虫的毒力表现出明显的增效作用,其共毒系数(CTC)分别为193.11和224.35。【结论与意义】除虫菊素、鱼藤酮、印楝素和苦瓜叶提取物对螺旋粉虱均具有较强的毒性;印楝素或鱼藤酮与除虫菊素(1:1)的混合物不仅能增强触杀效果,而且能延缓害虫抗药性的产生。 相似文献
2.
ITS sequences of 15 representative species of five sections in the genus Populus L. were determined. By using direct sequencing of PCR product, it was found that the fragments of internal transcribed spacers (ITS) are about 594 bp in length. The length of ITS-1 and ITS-2 is about 220 bp and 210 bp, respectively, while that of 5.8s is 164 bp. Its G+C content is about 69.0%. The number of phylogenetically informative loci is higher in ITS-2 than in ITS-1. Transversion and transition are two main factors that drive the ITS evolution, and more insertions and deletions occurred in ITS-2. Taking Salix matsudana Koidz. and Salix suchowensis Cheng as outgroups, phylogenetic analysis of ITS sequences using PAUP 4.0 software indicated that Populus is monophyletic group and can be divided into two main clades. One is the section Leuce , and the other is the remaining sections. 相似文献
3.
Protoplasts derived from common wheat ( Triticum aestivum L. cv. Jinan 177) were fused with UV-treated protoplasts of Agropyron elongatum (Host) Nevski by PEG method, and fertile asymmetric somatic hybrid plants resembling wheat morphology were obtained. The F2 hybrid plants could be divided into 3 types according to their morphology. Type Ⅰ hybrids had high and loosely standing stalks with big spikes and grains. TypeⅡ hybrids were dwarf and compact in shape with high tillering ability and smaller spikes. Type Ⅲ hybrids were similar to typeⅠas a whole but had more compact and erect spikes. All the F2 hybrid lines were superior to wheat in seed protein content, although some difference existed between themselves. Protein analysis of immature embryos and flag leaves from hybrids by two-dimensional electrophoresis showed that they possessed characteristic proteins of both parents and some new proteins. There existed also some different kinds of proteins in different lines. 相似文献
4.
A water soluble, (1→6)-branched, (1→4)linked D-glucan (LB-B1),[α]21D=+174.2° (c 0.87, H2O), was obtained from a hot-water extract of the sporoderm-broken spores of Ganoderma lucidum (Fr.) Karst by HPSEC, with 0.001 mol/L sodium hydroxide as the eluant, the molecular weight ( Mw ) of LB-B1 was estimated to be 9.3×103. From the results of total hydrolysis, methylation analysis, acetolysis and 1D, 2D NMR experimentation, it was concluded that LB-B1 was composed of repeating units with the following structure:α-D-Glcp-(1→6)-α-D -Glcp-(1→6)-α-D-Glcp 1↓6→4)-α- D -Glcp-(1→4)-α- D -Glcp-(1→4)-α- D -Glcp-(1→4)-α-D-Glcp-(1→4-)-α-D-Glcp-(1→)n 相似文献
5.
6.
7.
8.
9.
cDNA encoding caffeoyl CoA O-methyltransferase (CCoAOMT) from Chinese white poplar ( Populus tomentosa Carr.) was cloned by RT-PCR and sequenced. Northern analysis displayed that the CCoAOMT was expressed specifically in the developing secondary xylem and its expression was coincident with lignification. The antisense CCoAOMT cDNA was transformed into P. tremula×P. alba mediated by Agrobacterium tumefaciens (Smith et Townsend) Conn. Transgenic plants were identified with PCR, PCR-Southern and Southern analysis. Lignin content in 5- to 6-month-old transgenic plants was measured. One of the transgenic lines had significant reduction of 17.9% in Klason lignin content as compared with that of untransformed poplar. The results demonstrate that antisense repression of CCoAOMT is an efficient way to reduce lignin content for improving pulping property in engineered trees. 相似文献
10.
11.
12.
13.
14.
BRX基因家族是一类植物特有的转录因子家族,在拟南芥中参与调节根细胞的增殖与伸长。利用生物信息学方法对葡萄基因组中存在的BRX基因家族进行了电子克隆,并对其进行了基因组的定位、蛋白质的结构、理化性质、二级结构及亚细胞定位的预测与分析,并对其与其它植物进化的亲缘关系进行了研究。基因组定位结果发现:葡萄基因组中6个BRX基因集中分布在3条染色体上,其中Vv BRX1和Vv BRX2分布在第2条染色体上,Vv BRX3和Vv BRX4分布在第9条染色体上,Vv BRX5和Vv BRX6分布在第11条染色体上;编码蛋白的氨基酸数目为360~560个,Vv BRX5的相对分子量(61 884.4)和理论等电点(9.38)均最大,而Vv BRX1的相对分子量(40 239.1)和理论等电点(6.23)均最小。研究显示,不同成员间氨基酸数目、氨基酸序列间存在一定的差异,但都为疏水性蛋白;α-螺旋和无规则卷曲为6个BRX氨基酸序列的主要组成部分;均不存在跨膜域及信号肽。基因结构分析表明,6个BRX基因都含有外显子和内含子结构。亚细胞定位分析表明:6个Vv BRX基因均定位于细胞核。系统进化分析结果表明,Vv BRX1、Vv BRX2基因与胡杨的亲缘关系最近,相似性达96%;Vv BRX3、Vv BRX4与蓖麻、麻疯树、柑橘、可可、大豆聚为一类,说明其进化关系较近;Vv BRX5与其它Vv BRX基因明显分开;Vv BRX6基因与莲的亲缘关系最近。试验结果为葡萄BRX基因家族的克隆和功能分析奠定了一定的研究基础。 相似文献
15.
16.
17.
以Bt基因来源于中国的棉花品种泗抗1 号(常规种)、泗抗3 号(杂交种)和来源于美国的棉花品种99B(常规棉)、岱杂1 号(杂交棉)为材料,研究了不同高温水平下Bt 棉盛铃期铃壳中Bt 蛋白含量变化及氮代谢生理特征.结果表明: 铃壳中Bt 蛋白含量随温度升高而降低,与对照相比(32 ℃),常规棉品种在38 ℃、杂交棉品种在40 ℃以上时,铃壳中Bt 蛋白含量大幅度下降.其中,常规种泗抗1号和99B在38 ℃时分别下降53.0%和69.5%;杂交种泗抗3号和岱杂1号在40 ℃时下降64.8%和54.1%.铃壳Bt 杀虫蛋白含量下降显著时,其可溶性蛋白含量明显下降,游离氨基酸含量明显提高,GPT活性显著下降,蛋白酶活性显著增加.高温影响铃壳的氮代谢引起Bt蛋白的分解加剧,合成减弱,从而造成Bt蛋白含量减少,抗虫性下降. 相似文献
18.
为对家蝇Prohibitin蛋白序列进行生物信息学分析,从而为该基因功能研究奠定基础。利用在线分析程序和相关工具软件分析Prohibitin蛋白的理化性质、结构域、并预测其空间结构和功能。结果表明家蝇Prohibitin蛋白由277个氨基酸组成,分子量为30.54 k Da,理论等电点为5.26,为稳定蛋白,有跨膜区,但不含信号肽,该蛋白属于PHB保守结构域家族,亚细胞定位于细胞质,二级结构以α-螺旋为主。蛋白同源性比对结果显示,昆虫中的Prohibitin蛋白具有较高的同源性。这些分析结果可为今后深入研究该蛋白的结构特征和功能提供参考。 相似文献
19.