亚洲玉米螟对氰戊菊酯抗性遗传初步分析

亚洲玉米螟(Ostrinia furnacalis Guenee)在我国分布广,为害较重。近年来国内对该虫的分布、防治及抗药性方面做了大量的工作,但对该虫的抗性遗传研究尚不多。作者利用室内选育的氰戊菊酯抗性玉米螟品系及敏感品系做了抗性遗传研究,并采用生     

转cry1Ac玉米对亚洲玉米螟的抗性评价

目标性状的有效性评价是转Bt基因抗虫玉米研发和安全性评价研究的重要内容之一。采用酶联免疫吸附剂测定（ELISA）、室内生测和田间人工接虫鉴定研究了转cry1Ac玉米纯合群体BT-X和分离群体BT-38、BT-181、BT-43、BT-105等转化事件Cry1Ac蛋白的表达量以及对亚洲玉米螟Ostrinia furnacalis（Guenée）的室内杀虫和田间抗虫效果。转cry1Ac玉米鲜组织中Cry1Ac蛋白含量在44.07～438.00 ng/g之间,不同转化事件及不同组织之间差异显著,其中BT-X鲜花丝中Bt蛋白表达量显著低于未展开心叶。室内生测试验中除BT-43与对照没有显著差异外,取食其它转基因玉米心叶的亚洲玉米螟初孵幼虫6或7天的存活率为0～15.3%,显著低于非转基因对照;取食夏播BT-X鲜花丝6天的幼虫存活率为62.5%,显著低于Bt11及非转基因对照。田间心叶期接虫鉴定显示BT-X高抗亚洲玉米螟。说明转cry1Ac玉米BT-X、BT-181、BT-38和BT-105对亚洲玉米螟有很高的杀虫作用,BT-X田间抗虫效果良好。     

转cry1Ab/cry2Aj玉米对亚洲玉米螟的抗性评价

为探讨转cry1Ab/cry2Aj玉米对亚洲玉米螟Ostrinia furnacalis(Guenée)的抗性,采用室内生测和田间人工接虫鉴定方法评价了6个转cry1Ab/cry2Aj玉米品系对亚洲玉米螟的杀虫效果,并利用酶联免疫吸附法(ELISA)测定了Cry1Ab蛋白在各品系主要组织的表达水平.结果显示,亚洲玉米螟幼虫取食转基因玉米各品系雄穗、苞叶、花丝和雌穗48 h后死亡率在90％左右,取食心叶的死亡率在70％左右,96h后大部分幼虫死亡,而取食非转基因玉米的死亡率为3.3％～8.7％;春播和夏播田转基因玉米叶片、茎秆、雌穗基本没有被害,而对照玉米叶片、茎秆、雌穗被害严重,春播和夏播玉米平均每株分别有2.9、2.3头幼虫和蛹,2.8、3.4个蛀孔,隧道长度为7.5、14.2 cm,雌穗被害级别为5.3和5.1;6个转基因玉米品系中Cry1Ab蛋白在心叶、雄穗、花丝、苞叶和雌穗中稳定表达.综合评价认为,转基因玉米各品系在整个生育期内对亚洲玉米螟有很好的抗性,其中N50品系抗虫效果最佳,可以作为抗虫转多基因玉米育种的备选材料.     

玉米螟赤眼蜂防治云南亚洲玉米螟的田间效果

亚洲玉米螟Ostrinia furnacalis(Guenée)是云南省玉米上的主要害虫,在德宏州盈江县勐弄乡勐典村和苏典乡勐嘎村开展了释放玉米螟赤眼蜂Trichogramma ostriniae Pang et Chen防治亚洲玉米螟田间试验,结果表明,释放玉米螟赤眼蜂对亚洲玉米螟的田间防治效果显著,平均校正寄生率分别为74.27%和76.30%,被害株减退率分别为62.28%和66.50%,百秆活虫减退率71.76%和76.74%,虫孔减退率分别为63.83%和75.24%,平均防治效果分别为65.96%和72.82%;总平均挽回产量损失率7.79%,平均每公顷挽回经济损失420.06元,投入产出比1:1.47。     

玉米自交系心叶期对亚洲玉米螟抗性遗传规律的研究初报

不同抗螟性亲本所组配的F_1代在玉米心叶期,对亚洲玉米螟 Ostrinis furnacalis(Guenée)抗性研究表明,玉米抗螟牲为数量遗传,亲本抗性在杂种后代中具有累加效应,杂种的抗性与双亲平均抗性呈高度正相关。中等以上抗性亲本组配的 F_1代为抗螟型。而以中抗系组配杂种时,不论父本或母本,只要一个亲本为感螟系,则 F_1代均为感螟型。不同水平抗性亲本组配的正反交组合 F_1代差异极显著。     

转基因抗虫耐除草剂复合性状玉米‘双抗12-5’对亚洲玉米螟的抗性及对草甘膦的耐受性研究

通过田间接虫、室内生测以及田间植株喷施草甘膦试验,在吉林省公主岭市综合评价了转cry1Ab/cry2Aj和G10evo-epsps基因抗虫耐除草剂复合性状玉米‘双抗12-5’对亚洲玉米螟[Ostrinia furnacalis(Guenée)]的抗性以及对草甘膦的耐受性,为‘双抗12-5’在吉林省产业化应用提供基础科学数据。结果表明,与非转基因对照‘郑单958’相比,‘双抗12-5’全生育期对亚洲玉米螟都具有良好的抗性,达到高抗水平;取食‘双抗12-5’心叶、雄穗及花丝等组织7d后的亚洲玉米螟幼虫存活率为4%~12%,而取食‘郑单958’各个组织的亚洲玉米螟幼虫存活率均高于96%。‘双抗12-5’在喷施推荐剂量(1 230g/hm2)及在2倍推荐剂量(2 460g/hm2)草甘膦情况下,4周内均生长正常,受害率为0;对照‘郑单958’植株第一周即表现出明显的药害症状,逐渐枯萎死亡,受害率达到100%。综上所述,‘双抗12-5’在吉林省表现出良好的抗虫性和除草剂耐受性。     

亚洲玉米螟卵龄对玉米螟赤眼蜂寄生与发育的影响

室内观察了不同发育龄期的亚洲玉米螟卵对亚洲玉米螟赤眼蜂寄生能力的影响及寄生发生后二者的发育情况。结果发现，25℃下，亚洲玉米螟卵在产下96h后开始孵化。赤眼蜂的寄生发生率随寄主龄期的增加而呈下降趋势，但未随亚洲玉米螟卵龄的增加而线性降低，84h寄主卵不能被成功寄生。以发育0～12h的卵为寄主时，赤眼蜂6h内所能寄生的寄主卵数、寄生后羽化蜂总数及雌蜂数最多，分别为14．9粒、20．0头和17．4头。6h寄生产生的总后代数量受供试寄主卵龄的影响显著，基本随寄主卵龄的增加而下降，以0～12h最多，72～84h的最少。共计死亡蜂数以0～12h、12～24h和60～72h的处理较多；0～12h和60～72h卵为寄主时无羽化孔的寄主卵内完整死亡蜂数较其他时间的显著要高。除0～12h卵为寄主外，发育而未孵出的寄主幼虫数随供试寄主龄期的增高呈上升趋势，以72～84h的最高。在寄主卵龄期0～84h内的每一处理中，供试寄主卵的发育结果均有三种情况出现：①寄主幼虫孵化；②赤眼蜂羽化；③既无赤眼蜂羽化，亦无寄主幼虫孵出，且死亡的寄主卵数随供试寄主卵龄增加而增加。推测寄生发生后，在赤眼蜂和寄主胚胎间存在进攻与防御现象。     

亚洲玉米螟的天敌

本文综述了亚洲玉米螟,Ostrinia furnacalis(Gn.)的天敌种类与发生情况。目前有记录的天敌共136种,包括寄生性天敌68种,捕食性天敌63种,病原微生物5种。     

亚洲玉米螟的垂直分布

亚洲玉米螟在河北省张家口海拔1400 m以下地区均有分布。800 m以下地区是种群的主要分布区,以 500～600 m虫口密度最大。800 m以上发生程度一般很轻,其中个别地区因局部气候适宜,发生程度较为严重。同一海拔梯度内,水浇地与盆地的种群数量显著高于丘陵和旱地。不同寄主田内种群的分布比率,在海拔 800 m以下地区,玉米田高于谷子和高粱田,900 m以上地区谷子田明显高于玉米田。     

吉林省亚洲玉米螟的发生规律

通过对玉米秸秆垛中越冬代亚洲玉米螟的调查数据分析,明确了吉林省中部地区(公主岭)越冬代玉米螟蛹的始见期、始盛期、高峰期、盛末期和终见期.通过对田间系统调查数据分析,明确了一、二代玉米螟卵的始见期、始盛期、高峰期、盛末期和终见期.一代玉米螟卵的孵化率达90%以上,卵很少被寄生和捕食,一代幼虫化蛹率为89%～94%.二代玉米螟的田间整个落卵期卵粒赤眼蜂寄生率达70%,卵被捕食和脱落很少,在9月12日左右二代老龄幼虫占92.7%,未见二代幼虫化蛹.研究表明吉林省中部地区玉米螟已由每年发生1.5代转变为每年发生2代.并对导致世代数变化的可能原因进行了讨论.     

Effect of fraxinellone on growth and digestive physiology of Asian corn borer, Ostrinia furnacalis Guenee

A limonoid, fraxinellone significantly reduced the relative growth rate, food consumption rate as well as the efficiency of conversion of ingested food of the Asian corn borer, Ostrinia furnacalis when incorporated into artificial diets at concentration of 10 ppm and above. After being fed with diets that contained fraxinellone for 24 h, the larval midguts of O. furnacalis possess significantly lower activities of α-amylase and non-specific proteases and higher activities of cytochrome P450s. In vitro, the compound did not inhibit the activities of α-amylase and non-specific proteases extracted from the larval midguts. The modes of action of fraxinellone against the insect were discussed.     

亚洲玉米螟幼虫体内储存蛋白cDNA片段克隆与序列分析

为研究亚洲玉米螟Ostrinia furnacalis(Guen e)幼虫体内储存蛋白(SP)表达调控的分子机制,根据不同昆虫储存蛋白基因序列的保守区域,设计合成简并引物,采用RT-PCR技术从亚洲玉米螟5龄幼虫中扩增出一段cDNA片段,大小为892bp,编码297个氨基酸,预测分子量为35.7kD,理论等电点pI值为8.73。该基因序列中含有保守的幼虫储存蛋白(LSP)两个特征基序YFTEDIDLNTYYYYFHVDYP和TALRDPVFC。Blast P分析结果表明:该片段推导的氨基酸序列与斜纹夜蛾Spodoptera litura适量甲硫氨酸SP-1的一致性最高,为77%;与小菜蛾Plutella xylostella富含甲硫氨酸SP-1和SP-2、印度谷螟Plodia interpunctellaSP、美国白蛾Hyphantria cuneaSP-2和粉茎螟Sesamia nonagrioides适量甲硫氨酸SP氨基酸序列的一致性分别为74%、74%、72%、71%和65%。构建系统发育树分析了9种鳞翅目昆虫储存蛋白进化关系,结果显示:亚洲玉米螟cDNA片段氨基酸序列与小菜蛾富含甲硫氨酸SP-1的亲缘关系最近,与粉茎螟适量甲硫氨酸SP亲缘关系最远。     

Sublethal effects of larval treatment with deltamethrin on moth sex pheromone communication system of the Asian corn borer, Ostrinia furnacalis

The first, third, and fifth instar larvae of Asian corn borer, Ostrinia furnacalis (Guenée) (Lepidoptera: Pyralidae), were treated with a lethal dose 30% of deltamethrin to determine its sublethal effects on chemical communication of the adult survivors. The capability of all males surviving deltamethrin to contact the pheromone source in a wind tunnel was significantly reduced, but those treated as the first and third instars also exhibited lower percentages of `orientation,' `up-wind flight,' and `approaching' behaviors than the control males. Female moths from the deltamethrin treatment exhibited similar calling periodicity and percentages to the control moths during 10-h scotophase. However, approximately 20% of the females that survived the pyrethroid in the first and third instars contained significantly higher amounts of sex pheromone and wider coefficients of variation of the ratio of E12-tetradecenyl acetate to its Z isomer in those female survivors. There was no significant difference in the pheromone titers and coefficients of variation in control females and the females treated in the fifth instars. The present study indicates that the Asian corn borer may possess a compensation system by which the males that survived treatment at larval stage present a lower response to the pheromone, while the female survivors produce and release more pheromone.     

亚洲玉米螟6-磷酸葡萄糖异构酶基因(Pgi)全序测定及分析

为进一步从核酸水平上研究亚洲玉米螟Pgi基因相关特性,采用反转录PCR及RACE等技术对该基因编码序列及DNA全序列进行了测定,与Gen Bank中其它昆虫Pgi基因相关信息进行比较分析,并构建了系统发育树。结果表明:亚洲玉米螟Pgi基因编码区序列长为1 671 bp,共编码556个氨基酸;其DNA序列全长为10 078 bp(短序列为9 311 bp),由12个外显子与11个内含子镶嵌而成;各外显子长度与鳞翅目大部分昆虫相同,介于95~188 bp之间,内含子序列总长度为8 407 bp(短序列为7 640 bp),各内含子长度介于418~1 547 bp之间,且在内含子3、4、5、11上均发现杂合现象。系统发育结果显示,大部分昆虫Pgi基因c DNA严格按物种聚类,除了双翅目的家蝇Musca domestica与黑森瘿蚊Mayetiola destructor出现一定的交叉现象外,其余没有出现交叉现象。     

Summation and gradient characteristics of local electroantennogram response of the European corn borer, Ostrinia nubilalis

Summation and gradient characteristics of the electroantennogram (EAG) responses of male moths of the European corn borer (Ostrinia nubilatis) to their pheromone, (Z)-11-tetradecenyl acetate, were studied. Direct evidence that the summation of the locally elicited EAGs contribute to the overall response amplitude is presented; if two simultaneously stimulated loci were separated by more than 1 mm, the observed response was the summation of the two independent local EAGs. Configuration of the local EAG response was obtained at various loci of the antenna. It was demonstrated that a gradient in the amplitude of the local EAG exists along the antennal axis and that this gradient has its origin in the epithelial layer of the antenna. Several possible morphological and physiological factors affecting the response characteristics were considered.     

Cry1Ac毒蛋白对亚洲玉米螟生长发育和种群增长的影响

以含不同浓度的Cry1Ac毒蛋白的人工饲料(不加毒蛋白为对照)饲喂亚洲玉米螟幼虫,采用实验种群生命表的方法,测定了Cry1Ac毒蛋白对亚洲玉米螟的控害作用。结果显示,含2 000.0ng/g Cry1Ac毒蛋白的人工饲料处理该虫第5天的幼虫存活率为0;200.0、20.0 ng/g CrylAc毒蛋白处理第10、15天的幼虫存活率、化蛹率、成蛾率、净增长率和种群增长指数均显著低于对照,且高浓度处理显著低于低浓度处理;200.0 ng/g CrylAc毒蛋白处理的世代平均周期和种群加倍时间显著长于其它处理;而200.0 ng/g CrylAc毒蛋白处理的周限增长率显著小于2.0、0.2 ng/g处理。表明微量的Cry1Ac毒蛋白对亚洲玉米螟的种群增长有显著影响,且随着浓度的增加控制作用增强。     

Effects of the synergist S,S,S-tributyl phosphorotrithioate on indoxacarb toxicity and metabolism in the European corn borer, Ostrinia nubilalis (Hübner)

The toxicity of the oxadiazine insecticide indoxacarb to the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), was evaluated in the presence and absence of S,S,S-tributyl phosphorotrithioate (DEF), an inhibitor of hydrolytic metabolism. Bioassays involving topical application of different concentrations of indoxacarb to third instars of a susceptible O. nubilalis laboratory strain were performed, and in vitro metabolism experiments involving [¹⁴C] indoxacarb were examined to determine the role of hydrolytic metabolism in indoxacarb activation. Indoxacarb toxicity decreased in the presence of DEF indicating antagonism of toxicity. Results of in vivo and in vitro inhibition experiments indicated a reduction of indoxacarb activation and formation of the hydrolytic metabolite. These results are consistent with the proposed mechanism of hydrolytic activation for this compound.     

辣椒品种营养组成和绒毛特征与抗侧多食跗线螨的关系

利用螨量比值法,研究11个辣椒品种叶片茸毛密度和长度、叶绿素含量、可溶性糖含量、可溶性蛋白质含量和游离氨基酸含量与抗侧多食跗线螨Polyphagotarsonemus latus (Bank)的关系,以期阐明辣椒品种对侧多食跗线螨的抗性机制.结果显示,螨量比值与辣椒品种叶片绒毛密度、单位面积叶绿素含量和可溶性糖含量呈显著负相关,相关系数分别为-0.8455、-0.8851和-0.6712;与游离丝氨酸含量呈极显著负相关,相关系数为-0.829;与游离氨基酸总量和可溶性蛋白质含量无显著相关性.研究表明,辣椒品种对侧多食跗线螨的抗性与叶片叶绿素、可溶性糖、游离丝氨酸含量及叶片绒毛密度有关.     

Biological and biochemical parameters of Biomphalaria alexandrina snails exposed to the plants Datura stramonium and Sesbania sesban as water suspensions of their dry powder

Four plant species, as a dry powder of their leaves, were tested against Biomphalaria alexandrina snails, the intermediate host of Schistosoma mansoni. The bioassay tests revealed the plants Datura stramonium and Sesbania sesban to be more toxic to the snails than the other two ones. Therefore, they were tested against snails’ fecundity (M_x), reproduction rate (R_o) and their infection with S. mansoni miracidia. In addition, total protein concentration and the activities of the transaminases (AsT and AlT) and phosphatases (AcP and AkP) enzymes in hemolymph and tissues of snails treated with these plants were determined. As well, glucose concentration in snails’ hemolymph was evaluated.Exposure of snails for 4 weeks to LC₁₀ and LC₂₅ of the plants D. stramonium and S. sesban dry powder markly suppressed their M_x and R_o. The reduction rates of R_o for snails exposed to LC₂₅ of these plants were 62.1% and 76.4%, respectively. As well, a considerable reduction in the infection rates of snails exposed to these plants either during, pre- or post-miracidial exposure was recorded. Thus, infection rates of snails treated during miracidial exposure with LC₁₀ of D. stramonium and S. sesban were 41.7% and 52.2%, respectively, compared to 92.6% for control group (P < 0.01). These plants, also, reduced the duration of cercarial shedding and cercarial production/snail. So, snails exposed to LC₂₅ of these plants shed 372.8 and 223.2 cercariae/snail, respectively, compared to 766.3 cercariae/infected control snail (P < 0.01).The results, also, revealed that glucose and total protein concentrations in hemolymph of snails treated with LC₁₀ and LC₂₅ of these plants were decreased, meanwhile, the activities of the enzymes AsT, AlT, AcP and AkP were elevated (P < 0.01). However, the activity of AcP in tissues of treated snails was decreased compared to that of control ones. It is concluded that LC₂₅ of the plants D. stramonium and S. sesban negatively interferes with biological and physiological activities of B. alexandrina snails, consequently it could be effective in interrupting and minimizing the transmission of S. mansoni.