斯氏线虫对黄曲条跳甲种群系统控制研究

将斯氏线虫作为一个生物控制因子引入黄曲条跳甲种群系统中,把斯氏线虫对该跳甲各虫期的感染率作为量化指标,应用种群发展趋势指数(I)和干扰作用控制指数(IIPC)分析方法,评价斯氏线虫对黄曲条跳甲自然种群的控制作用。结果表明,十字花科蔬菜田中每hm~2施用7×10~9条斯氏线虫对黄曲条跳甲种群有明显控制作用,对照区的种群趋势指数为12.9,处理区的种群趋势指数下降为2.39。斯氏线虫对黄曲条跳甲种群干扰作用控制指数为0.2,即线虫处理区的下代跳甲种群密度将是对照区的0.2倍。     

斯氏线虫对黄曲条跳甲田间种群的控制作用

在广州,深圳等多个地点的田间试验结果表明,土壤施用斯氏线虫(Steinernema carpo-capsae)Agriotis 品系的侵染期线虫悬浮液来控制黄曲条跳甲(Phyllotreta striolata)幼虫的种群数量,当线虫剂量为100万条/m~2时,线虫的寄生率为40%—70%,有效虫口密度下降38%～84%;以50万条/m~2剂量的线虫与低浓度(1∶1000)的敌百虫混合施用,对跳甲的作用效果和前一种处理所取得的效果相接近。线虫施进土壤后15—20天内对跳甲幼虫尤其是三龄幼虫种群数量控制作用较好,超过这段时间其作用明显下降。因此,在蔬菜移栽至收割期间,施用二至三次100万条/m~2剂量的线虫悬液或50万条/m~2剂量的线虫与1000倍的敌百虫混合液,对黄曲条跳甲可取得较好的防治效果。     

防治有机蔬菜上黄曲条跳甲的药剂筛选

黄曲条跳甲是严重为害蔬菜的害虫之一,为筛选防治有机蔬菜上黄曲条跳甲较为安全、高效的药剂,进行了室内和田间防虫试验。调查供试投入品室内杀虫效果发现,质量浓度为125 mg/L的鱼藤酮和20 mg/L的印楝素对黄曲条跳甲的致死率较高,药后第2天致死率分别达100%和86.67%。田间防效的调查结果表明,5%鱼藤酮可溶液剂112.5 g/667m~2对黄曲条跳甲的虫口防效达93.45%,显著高于其他处理。在另一试验中发现,1亿尾/667m~2的昆虫病原线虫海绵制剂对黄曲条跳甲的控制效果明显。     

植物源甘油酯与金龟子绿僵菌对黄曲条跳甲的室内毒力及田间防效评价

黄曲条跳甲Phyllotreta striolata是为害十字花科蔬菜的重要害虫,长期使用大量的化学农药,不仅增强了黄曲条跳甲的耐药性,也会导致蔬菜农药残留增加,危害人们的饮食健康。因此,利用绿色防控手段防治害虫成为近些年的研究热点。本文在室内测定了以植物源甘油酯为主要成分的植物油乳剂、绿僵菌以及二者混配液对黄曲条跳甲成虫的毒力并对油菌混配液的田间防控效果进行了评价。室内毒力测定结果表明,施用植物油乳剂50～800倍液时,黄曲条跳甲成虫第2 d的死亡率为37.93%～100%;施用绿僵菌1.25×10⁷～2×10⁸孢子/m L时,黄曲条跳甲成虫第5 d的死亡率为32.2%～93.22%;施用植物油乳剂和绿僵菌混配液时,黄曲条跳甲成虫第1 d的死亡率在95%以上,显著高于2种单剂,且混配液能够极显著缩短黄曲条跳甲致死中时。田间试验结果表明,以植物油乳剂100倍液和绿僵菌1×10⁸孢子/m L混配处理第6 d时,黄曲条跳甲成虫的相对防效和虫口减退率均达60%以上,第8 d时,黄曲条跳甲成虫的相对防效和虫口减退率分别为89.8...     

苏云金杆菌G033A对萝卜黄曲条跳甲的防治效果研究

黄曲条跳甲是为害十字花科蔬菜的重要害虫之一,威胁湖北省蔬菜产业的生产和发展.为了探究苏云金杆菌G033A可湿性粉剂对黄曲条跳甲的防治效果,设计了3个不同处理浓度进行试验,结果表明,667m~2用量为100、150、200g,其药后7d防效分别为72.4%、85.6%和87.4%,其中667m~2用150～200g的防效显著高于对照药剂5%啶虫脒乳油.从经济有效角度出发,在成虫盛发初期施用苏云金杆菌G033A效果最佳.施药时间应选择阴天或晴天傍晚,其推荐用药量为667m~2施用150～200g.     

昆虫病原菌防治萝卜黄曲条跳甲田间应用技术

黄曲条跳甲是为害十字花科蔬菜的世界性害虫。本文研究了昆虫病原菌苏云金杆菌工程菌G033A和金龟子绿僵菌CQMa421防治萝卜黄曲条跳甲田间应用技术。结果表明,采用昆虫病原微生物苏云金杆菌G033A和金龟子绿僵菌CQMa421土壤处理防治黄曲条跳甲均具有较好的防效,其中32000 IU/mg苏云金杆菌工程菌G033A可湿性粉剂300 g/667 m²土壤处理防治效果显著优于对照化学药剂,且持效期较长,具有明显的减药、省力、降成本作用。针对萝卜主要病虫害开展了全程生物防控技术示范,结果表明全程生物防控技术不仅防治效果好,且较常规化学防治技术增产达到14.8%,品质得到提升,商品优良率提高12%,可进一步大面积示范推广。     

应用斯氏线虫防治桑皱鞘叶甲

应用斯氏属小卷蛾线虫Steinernema carpocapsae(A24品系）对桑皱鞘叶甲Abirus fortunei(Baly）进行了室内和田间感染试验。在25～30℃的室内条件下，1500～2000条线虫/ml的处理使桑皱鞘叶甲幼虫感染率达86%～100%。在9～10月份，先清除田间杂草，然后在桑园开沟，按45～75万条线虫/m^2的剂量施用小卷蛾线虫，对幼虫的防治效果可达88.3%～96.2%，并使次年成虫的出土数量减少46.2%～86.7%。此种防治方法，避免了在春蚕期间摘叶饲蚕与桑皱鞘叶甲化学防治的矛盾，显示出应用昆虫病原线虫防治桑皱鞘叶甲的良好前景。     

9种杀线剂对香蕉根结线虫病的防效评价

对9种不同作用机理的杀线虫制剂进行了田间防效评价试验。结果表明,10%噻唑磷颗粒剂、35%威百亩水剂和98%棉隆微粒剂对根结线虫具有良好的防效,不仅能控制土壤中2龄幼虫数量,而且能非常有效地抑制根结的形成,同时具有速效性好、持效期长、残留毒性低等优点,可作为根结线虫防治的首选药剂;5%丁硫克百威颗粒剂和0.5%阿维菌素颗粒剂具有较好的防效,对土壤中2龄幼虫数量和作物根结的形成具有中等水平的控制能力,速效性好、同时具有一定的持效性;生防制剂5亿活孢子/g淡紫拟青霉颗粒剂和2.5亿孢子/g厚孢轮枝菌微粒剂在香蕉生长前期防效较差,而在生长中期的防效逐渐上升并保持稳定;2.5%二硫氰基甲烷可湿性粉剂的表现一般,但可在生长季节多次灌根使用,同时具有毒性低、使用方便的优点,是当前为数不多的、能在作物生长季节里施用的广谱型杀线虫制剂;50%氰氨化钙颗粒剂的表现最差,仅能一定程度地控制根结线虫数量,未能有效地抑制病害的发展,对2龄幼虫的控制能力不超过60 d,生长中后期的2龄幼虫数量和根结指数增长较快。     

黄曲条跳甲幼虫致病菌的鉴定及其对黄曲条跳甲的杀虫活性研究

从自然死亡黄曲条跳甲幼虫体中分离出1株对黄曲条跳甲幼虫和成虫有较高致病性菌株PS-1。通过病原菌的形态观察、Biolog系统鉴定以及16S rDNA序列测定分析,确定菌株PS-1隶属于肠杆菌科、沙雷氏菌属的粘质沙雷氏菌Serratia marcescens族群。用菌株PS-1浓度为3×104、3×106和3×108 cfu/mL的菌悬液浸泡鲜萝卜块饲喂黄曲条跳甲幼虫24 h,4 d后的校正死亡率分别为36.1%、63.9%和75.0%;2、3和4 d的LC50分别是7.98×106、4.27×106和8.02×105 cfu/mL。用浓度1×108 cfu/mL的菌悬液处理菜心叶片饲喂黄曲条跳甲成虫,12 d的校正死亡率为23.25%。用浓度1×105、1×107和1×109 cfu/mL的菌悬液浸渍黄曲条跳甲卵,其孵化率与对照无显著差异。结果表明,粘质沙雷氏菌PS-1菌株对黄曲条跳甲成虫和幼虫有较强的毒力,在黄曲条跳甲的生物防治方面具有一定的应用前景。     

不同杀虫剂对黄曲条跳甲的室内毒力和田间防效

为明确多种杀虫剂对黄曲条跳甲的防治效果,通过浸叶法测定乙基多杀菌素、噻虫嗪、高效氯氰菊酯等14种杀虫剂对黄曲条跳甲的室内毒力,并选室内毒力较高的杀虫剂开展田间试验以验证其防效。结果表明,供试14种杀虫剂中,以乙基多杀菌素对黄曲条跳甲成虫的毒力最高,LC_(50)(致死中浓度)为31.97 mg/L;啶虫脒(LC_(50)=70.27 mg/L)、甲维盐(LC_(50)=96.41 mg/L)、噻虫嗪(LC_(50)=138.13 mg/L)、高效氯氰菊酯(LC_(50)=142.64 mg/L)也具有较高毒力;吡虫啉(LC_(50)=249.97 mg/L)、噻虫胺(LC_(50)=272.99 mg/L)毒力一般;其他药剂毒力较低(LC_(50)350 mg/L),杀虫单对黄曲条跳甲则基本无效(LC_(50)2 000 mg/L)。田间试验表明,60 g/L乙基多杀菌素悬浮剂、40%啶虫脒水分散粒剂和25%噻虫嗪水分散粒剂对白萝卜田黄曲条跳甲防效较好,药后第7天防效大于80%。综合分析室内毒力和田间药效,乙基多杀菌素、啶虫脒、噻虫嗪等药剂可作为田间防治黄曲条跳甲的候选药剂。     

植物保护剂保卫德对黄曲条跳甲种群的控制作用

通过室内外试验评价了植物保护剂保卫德(BIOACT-T35)对黄曲条跳甲Phyllotreta striolata(F.)种群的控制作用。结果表明,其控制作用主要表现在对成虫的显著忌避和拒食作用。10.00 ml/L的忌避作用为91.42％,选择性和非选择性拒食率分别为93.54％和85.79％,种群趋势指数(I值)由对照的3.8680降为0.3676,干扰作用控制指数(IIPC)为0.0950。采用状态空间分析法的模拟结果表明,其控制作用表现在种群发展初期对成虫的忌避作用。     

Systemic nematicidal activity of fluensulfone against the root-knot nematode Meloidogyne incognita on pepper

BACKGROUND: Fluensulfone, a new nematicide of the fluoroalkenyl group, has proved to be very effective in controlling root‐knot nematodes, Meloidogyne spp., by soil application. The systemic activity of this compound against M. incognita on peppers via soil drenching and foliar spray was evaluated. RESULTS: Root application of fluensulfone via soil drenching showed slight and no nematode control activity when applied 4 and 10 days, respectively, after inoculation. A single foliar spray of peppers with a fluensulfone solution at 3.0 g L^?1 prior to inoculation reduced the galling index by 80% and the number of nematode eggs by 73–82% of controls. The reduction in these parameters by fluensulfone was much higher than that obtained with oxamyl or fenamiphos at the same concentration. This activity was also observed when the plants were sprayed 21 days before inoculation. A series of experiments suggested that foliar spray with fluensulfone prior to inoculation reduces nematode invasion. However, foliar spray after inoculation did not inhibit nematode development inside roots. CONCLUSION: Fluensulfone showed relatively high nematode control activity when sprayed on the foliage before inoculation. Fluensulfone may be used as a foliar application, in addition to soil application, for root‐knot nematode control. Copyright © 2011 Society of Chemical Industry     

马铃薯腐烂茎线虫RPA-LFD可视化快速检测方法的建立

 马铃薯腐烂茎线虫是为害我国甘薯和马铃薯的一种重要植物病原线虫,也是我国重要的检疫性有害生物。为实现对该线虫的准确、快速且可视化的检测,本研究以马铃薯腐烂茎线虫rDNA-ITS序列为靶标构建了重组酶聚合酶结合侧流层析试纸条(RPA-LFD)的可视化快速检测体系。该体系可在39 ℃条件下15 min内特异性地完成对马铃薯腐烂茎线虫的检测,对A型(甘薯种群)和B型(马铃薯种群)单头线虫(J4)的检出底限均为3 125^-1头线虫,可以直接对土壤和甘薯茎中的马铃薯腐烂茎线虫进行检测,灵敏度可达1头(J4)/10 g土壤和1头(J4)/2 g甘薯茎组织。该体系操作简便、成本低廉、结果可视,可为马铃薯腐烂茎线虫的早期预警和口岸检疫提供技术支撑。     

松材线虫mapk基因克隆及RNAi效应分析

促分裂原活化蛋白激酶(Mitogen Activated Protein Kinase)在线虫生长发育过程中具有重要作用。本研究利用RACE方法克隆了松材线虫mapk基因,其基因全长1 744 bp,5'UTR长243 bp,3'UTR长81 bp,含有一个1 098 bp的开放读码框,包括6个外显子和5个内含子,为单拷贝基因,其预测的蛋白序列与其他线虫的序列相似性为77.66%~84.01%。通过体外转录合成341 bp的dsRNA,将松材线虫的幼虫浸泡在1.5 mg·mL-1dsRNA中24 h后,mapk表达量下降约85%,松材线虫的死亡率约为对照的4.2倍,经dsRNA浸泡的成虫,繁殖能力下降约50%,表明mapk基因的沉默可能抑制松材线虫的繁殖能力。     

Influence of some hardwood barks as soil amendments onRotylenchulus reniformis reproduction and growth response of sunflower

Four hardwood barks (HWB) i. e.Acacia arabica (AA),Ficus sycomorus (FS),Morus alba (MA) andZiziphus spinachristi (ZS) were tried as soil amendments at 0.5, 1.0 and 1.5% rates w/w for control ofRotylenchulus reniformis and improvement of cv. Giza 1 sunflower growth under greenhouse conditions. All HWB with various concentrations significantly (P≤0.01) reduced numbers of larvae in soil, both females and eggmasses on roots, total final nematode population as well as the nematode build-up as compared to control. 1.5% rate of ZS, AA and MA barks were most effective in reducing numbers of larvae in soil, total final nematode population and the nematode build-up. Also, 1.5% rate of each of FS and AA barks were most effective in reducing numbers of females or eggmasses, respectively. On the other hand, the least reduction in the previous nematode stages and rate of build-up was observed with 0.5% dose of FS bark. Shoot weights were increased significantly with both of 1.0% and 1.5% doses of each of FS and ZS barks and only with 1.5% dose of MA bark. Both shoot lengths and root weights increased significantly with 1.5% dose of all HWB or with 1.0% dose of each of AA and ZS barks as compared to control. No significant increase in root lengths was observed. Generally, there were positive significant correlations between doses of HWB, each of the reductions in the previous nematode stages and increases in sunflower growth criteria.     

不同氮素对根结线虫及土壤微生物的影响

为筛选根结线虫控制技术,采用传统平板法和Biolog ECO生态板评价了液氨、氨水和碳酸氢铵3种氮素对根结线虫及土壤微生物的影响。结果表明,等氮条件下液氨处理杀线虫效果最好且黄瓜产量最高,氨水次之。液氨用量在375.0 kg/hm~2的条件下,对黄瓜根结线虫的防效达到71%,和10%噻唑膦颗粒剂(GF)45.0 kg/hm~2处理相比效果没有显著差异(79.9%)。种植前,细菌数量、AWCD值、Shannon指数、McIntosh指数和Simpson指数均随着液氨用量的增加而减少,随着氨水和碳酸氢铵用量的增加而增加;但所有处理均显著降低了土壤真菌的数量。黄瓜收获后,土壤细菌数量、真菌数量、AWCD值、Shannon指数、McIntosh指数和Simpson指数均随着氮素用量的增加而提高,且高于空白处理和10%噻唑膦GF 45.0 kg/hm~2处理。以上结果说明,液氨、氨水和碳酸氢铵不但可以作为土壤肥料,也可以作为一种高效、低价和生态化的根结线虫防治剂进行推广应用。     

Chitosan physico–chemical properties modulate defense responses and resistance in tobacco plants against the oomycete Phytophthora nicotianae

Enzymatic defense responses and protection against Phytophthora nicotianae were studied in tobacco plants treated with chitosan of different molecular weights (MW) and degrees of acetylation (DA). The concentration and mode of chitosan application affected enzymatic induction in tobacco leaves. β-1,3-Glucanase (EC 3.2.1.6) activity required 10 times the polymer concentration relative to the oligochitosan mixture to induce the highest activity above control when treated by foliar spray, indicating the influence of molecular weight in this response. PAL (EC 4.3.1.5) and POD (EC 1.11.1.6) activities increased above control as a result of the influence of polymer degree of acetylation when treatments were applied by foliar spray. A higher DA favored PAL activity, whereas a lower DA induced higher POD activity. Using an in vitro bioassay, it was found that the three chitosan compounds caused a reduction of the infection index of P. nicotianae in tobacco plants that was dependent on elicitor concentrations. There was a significant relationship between the reduction of the infection index and an increase in PAL activity when chitosan was applied by foliar spray and by substrate drench to the plant rhizosphere. These results demonstrate the influence of chitosan physico–chemical properties in plant-induced resistance and the relevance of particular responses in plant protection against pathogens.     

昆虫病原线虫防治荔枝巢蛾

为害荔权树皮的新害虫荔枝巢蛾Ｃｍｏｒｉｔｉｓ ａｌｂｉｃａｐｉｌｌａ Ｍｏｒｉｕｔｉ在上发生１代,由于幼虫藏匿于自身吐丝粘粪粒组成的双层网下,使农药防治困难。作者以昆虫病原线虫为主,对比使用化学农药,寻求对该虫有效的防治方法。结果表明,荔枝巢蛾幼虫、蛹对昆虫病原线虫４个种的５个品系十分敏感,其感染率与病原线虫的剂量成正相关,Ｙ＝２．７３７＋１．２６４Ｘ,ＬＤ５０＝６．１６５ＩＪ／虫,但是大田防效很