转基因抗虫玉米对亚洲玉米螟生长发育和实验种群增长的影响

以两个转Bt抗虫基因玉米品系G03-2396、G03-2739和1个常规对照品种苏玉16为材料,研究其对亚洲玉米螟幼虫生长发育和实验种群消长动态的影响.结果表明:①两个转基因玉米材料的心叶组织对玉米螟低龄幼虫的毒性很强,1龄幼虫取食这两个转基因玉米心叶组织后8 d死亡率超过97%;2龄幼虫取食心叶组织8 d后死亡率超过80%;1～4龄幼虫或全部死亡不能化蛹,或平均蛹重与对照品种相比显著降低,仅5龄幼虫各测定指标与对照品种相比差异不显著;两个转基因玉米材料的雌穗组织对玉米螟幼虫的毒性较低,即使低龄幼虫取食8 d后的死亡率与对照苏玉16相比差异也不显著.②玉米螟高龄幼虫取食两个转基因抗虫玉米心叶后,存活的部分幼虫化蛹羽化后的成虫寿命明显缩短,单雌产卵量显著下降,甚至卵的孵化率也有所降低.表明所选的两个转Bt基因玉米品系对玉米螟的毒性具一定的后续效应.     

亚洲玉米螟幼虫在抗虫和耐除草剂转基因玉米上取食行为的变化

在室内条件下,研究转基因抗虫、耐除草剂复合性状玉米NF6373YGRR(通过杂交育种聚合cry1A.105、cry2Ab2、cp4epsps基因)对亚洲玉米螟[Ostrinia furnacalis(Guenee)]初孵幼虫和3龄幼虫取食行为与存活率的影响.结果表明:在48h非选择性试验中,玉米螟初孵幼虫在转基因玉米心叶组织上的取食率显著低于非转基因玉米,转基因玉米48h的幼虫累计死亡率为53.75%.非转基因玉米为20.00%,差异显著;3龄幼虫在转基因玉米雌穗尖组织上的取食率、死亡率与非转基因玉米差异不显著.在48h选择性试验中,初孵幼虫在转基因玉米心叶组织上的取食率显著低于非转基因玉米,48h累计死亡率为55.00%;3龄幼虫在转基因玉米雌穗尖组织上的取食率与非转基因玉米差异不显著.转基因抗虫、耐除草剂复合性状玉米对玉米螟初孵幼虫的取食有显著的抑制和忌避作用,而对3龄幼虫的取食行为影响不显著.     

转Bt基因抗虫玉米对亚洲玉米螟幼虫磷酸酯酶活性的影响

研究了转Bt基因抗虫玉米对亚洲玉米螟幼虫磷酸酯酶活性的影响,结果表明:取食Bt玉米后亚洲玉米螟幼虫体内的酸性磷酸酯酶活性在72 h后显著降低,碱性磷酸酯酶的活性则在24 h后就受到抑制,72 h时酶活与对照组的比值仅为0.3.随着取食时间增长,酶活力减弱,幼虫的体重也显著低于对照,两者存在一定相关性.     

转Bt基因玉米对亚洲玉米螟的抗性评价

转Bt基因抗虫玉米为诺华公司含Bt11转化系的杂交种NX4777,能全株表达Cry1Ab杀虫蛋白,以其非转基因受体玉米品种NX4906为对照。在玉米生长至心叶中期(50~60cm高)、抽雄前期和抽丝散粉期分别进行人工接亚洲玉米螟[Ostriniafurnacalis(Guenée)]初孵幼虫40~60头。以食叶级别、存活幼虫数、蛀孔数、隧道长度和雌穗被害级别等,分别作为评价玉米心叶期和穗期的抗性标准。结果表明,Bt玉米食叶级别仅为1级,显著低于对照的7级。Bt玉米平均每株存活幼虫0.04~0.20头、蛀孔0.11~0.15个、隧道长度0.13~0.41cm,雌穗被害级别为0,植株折茎率为0,而对照玉米平均每株存活幼虫6.19~12.41头、蛀孔4.48~7.05个、隧道长度12.41~24.09cm,雌穗被害级别为5.9,植株折茎率高达73.6%~95.5%。室内生测结果亦表明,取食Bt玉米心叶、雄穗的初孵幼虫3d全部死亡,取食花丝7d死亡率达到99%,相比之下取食常规玉米的存活率在88.7%以上。表明表达Cry1Ab杀虫蛋白的Bt对亚洲玉米螟具有很高的抗虫性,能够保护玉米全生育期免受玉米螟的危害。     

转Bt cry1F基因抗虫玉米对亚洲玉米螟幼虫存活率的影响

以不同用量的转Bt crylF基因抗虫玉米饲养亚洲玉米螟幼虫,研究人工饲料中转基因玉米对其存活率的影响。结果表明,随着人工饲料中转基因玉米用量的增加,亚洲玉米螟幼虫的存活率逐渐下降,在用量为100%处理时幼虫存活数仅3～5头,存活率仅15%～20%;在对照玉米处理中,4个处理的幼虫存活数均较高,为16～19头,存活率均在69%以上。转基因玉米处理的幼虫存活数与对照玉米处理相比,两者差异显著。     

转Bt crylF基因抗虫玉米对亚洲玉米螟幼虫存活率的影响

以不同用量的转Bt crylF基因抗虫玉米饲养亚洲玉米螟幼虫,研究人工饲料中转基因玉米对其存活率的影响.结果表明,随着人工饲料中转基因玉米用量的增加,亚洲玉米螟幼虫的存活率逐渐下降,在用量为100%处理时幼虫存活数仅3～5头,存活率仅15%～20%;在对照玉米处理中,4个处理的幼虫存活数均较高,为16～19头,存活率均在69%以上.转基因玉米处理的幼虫存活数与对照玉米处理相比,两者差异显著.     

氮素含量对亚洲玉米螟取食及选择性影响

【目的】研究亚洲玉米螟幼虫对不同氮素含量取食和选择特性,了解植物营养与昆虫选择之间的关系,为亚洲玉米螟幼虫的取食、选择提供理论依据。【方法】采用室内采用叶碟法对亚洲玉米螟进行取食选择实验,计算取食率;在室外人工模拟设计出5个氮肥施肥量处理,调查玉米螟的危害情况。【结果】亚洲玉米螟幼虫在 48 h 非选择实验中,接虫2 h后,在对照(N含量10.69%)和N₄(18.84%)的取食率最高,为58%,接虫第4~6 h,取食选择性依次为N₃>N₅>N₄>N₁>N₂,初孵幼虫在N₄(18.84%)的第8、12、36和48 h的取食率最高,依次为70.5%、67%、61.5%、63.5%;N₄(18.84%)上的取食率在36 h时达到最高,为43.3%,比对照高10%,N₅(30.31%)取食率在8 h时达到最高,为46.67%,比对照高20%,差异显著(P<0.05);不同氮素施肥量亚洲玉米螟发生为害中被害株率达到10%以上有2个处理,其中被害株率最高的是50 kg/667m²,达到22.89%,其次是40 kg/667m²为12.67%,二者差异不显著(P>0.05),但是与其他处理之间差异显著(P<0.05)。【结论】不同N素含量对亚洲玉米螟幼虫取食、选择具有显著影响,但是存在一定阈值,超过该值以后,取食率、被害株率等相对数据可能保持平稳或者往相反的方向发展。     

4种寄主植物对亚洲玉米螟生长发育的影响

为了弄清不同寄主植物对亚洲玉米螟生长发育的影响,室内研究了玉米(Zea mays)、甘蔗(Saccharum officinarum)、四季豆(Phaseolus vulgaris)、茼蒿(Chrysanthemum coronarium)对亚洲玉米螟发育历期、体重增长和龄期及成虫产卵量的影响。结果表明:相同条件下,亚洲玉米螟幼虫取食不同寄主植物后其虫龄存在较大差异,其中饲喂四季豆的种群中77.8%个体有4龄,饲喂玉米、甘蔗及玉米甘蔗混合食物后90%个体有5龄,而饲喂茼蒿的种群可达6龄。饲喂四季豆的亚洲玉米螟F1代幼虫总的发育历期最短,仅12.52 d,而饲喂玉米、玉米与甘蔗混合食物的个体发育历期显著长于其他处理,分别为31.0 d和28.17 d。F2代幼虫总发育历期比F1代短;F1代亚洲玉米螟末龄幼虫体重以饲喂四季豆的最大,单头体重达56.13 mg,与饲喂甘蔗的个体体重(51.80 mg)间无显著差异,且显著高于其他处理,而饲喂玉米+甘蔗的最低,仅27.88 mg,与饲喂茼蒿的(34.31 mg)无显著差异。不同寄主植物饲喂的亚洲玉米螟产卵量也有显著差异,以饲喂茼蒿的最高(217粒/雌)。F2代卵的孵化率比F1代低,且饲喂玉米、四季豆及茼蒿的F2代中雌虫比例明显高于雄虫,而饲喂甘蔗及玉米+甘蔗的雄虫比例较高。本研究结果将为进一步研究亚洲玉米螟种群分化及利用作物多样性种植控制亚洲玉米螟的机理提供基础数据。     

亚洲玉米螟发生动态及释放松毛虫赤眼蜂防治效果

于2007年6月和9月对秦皇岛亚洲玉米螟在春玉米田间落卵量和亚洲玉米螟为害春玉米的严重程度及7月29日分别在春玉米地和夏玉米地释放松毛虫赤眼蜂防治第二代亚洲玉米螟效果进行了调查与研究,结果表明,亚洲玉米螟在该地区全年共发生两代,产卵高峰期分别发生在6月中旬和8月上旬,高峰期卵粒数分别达到了800粒和748粒;田间花叶率、百株蛀茎孔数、蛀茎株率和百株蛀穗孔数、蛀穗株率分别达到了78%、340个、96%和102个、74%;松毛虫赤眼蜂在春玉米地和夏玉米地卵块寄生率分别达到了80.00%和81.44%,在夏玉米地,放蜂区和对照区相比,蛀茎虫孔减退率为53.05%,蛀穗虫孔减退率为69.63%。通过本文分析得出亚洲玉米螟在秦皇岛地区发生及危害严重,释放松毛虫赤眼蜂防治效果较好。     

丁布胁迫对亚洲玉米螟危害程度及生长发育的影响

异羟肟酸及其衍生物是广泛存在于玉米等禾本科作物中的一种广谱抗性物质,丁布（DIM-BOA）是玉米植株中含量最大的异羟肟酸。为了明确不同丁布含量的玉米品种对亚洲玉米螟危害和生长发育的影响,采用高效液相色谱法测定了11个玉米品种五叶期的丁布含量;室内条件下在玉米叶片上人工接虫,调查亚洲玉米螟在11个玉米品种上的危害程度;用丁布含量依次降低的登海662、浚单20、隆玉602品种（P＜0.05）叶片饲喂亚洲玉米螟初孵幼虫,探讨不同含量丁布胁迫下亚洲玉米螟生长发育的变化。结果表明,不同玉米品种间丁布含量差异显著,登海662含量最高,德单5号含量最低。接种亚洲玉米螟后,丁布含量较低的德单5号、隆玉602、新单36、金骆驼335品种的花叶指数均大于40％,随着玉米品种丁布含量的增加,玉米螟的危害程度逐渐减轻。亚洲玉米螟幼虫发育历期和幼虫＋蛹总历期在取食3个玉米品种处理之间具有差异,其中取食隆玉602的幼虫发育历期和总发育历期最短,取食浚单20的处理最长。取食3个玉米品种的亚洲玉米螟均不能正常交配产卵和完成世代周期,其化蛹率、蛹质量和羽化率均随玉米品种丁布含量的降低而升高。     

Effect of three insect-resistant maizes expressing Cry1Ie,Cry1Ab/Cry2Aj and Cry1Ab on the growth and development of armyworm Mythimna separata(Walker)

Three transgenic maize events(IE09 S034, Shuangkang 12–5 and C0030.3.5) produced Cry1 Ie, Cry1 Ab/Cry2 Aj and G10-EPSPS, Cry1 Ab and EPSPS, respectively, all of which target the Asian corn borer. The oriental armyworm Mythimna separata(Walker) is the secondary target. In this study, the effects of the three Bt maizes on the development and survival of armyworm were studied. The results showed that IE09 S034 had insecticidal activity against 1 st instar larvae, and the survival rate of armyworm fed with Bt maize for 10 days was 46.2%, significantly lower than that of the control. The larvae at 3 rd–6 th instar were more tolerant of the Bt toxin than the early instar larvae. However, Shuangkang 12-5 had good insecticidal activity against 1 st–5 th instar larvae. The mortality was nearly 100% when the larvae were fed with Shuangkang 12-5 before 3 rd instar, and the toxin had quick-acting efficacy. This event significantly inhibited the development of armyworm; that is, the larval duration of the 3 rd and 4 th instar larvae fed with Shuangkang 12-5 was prolonged by 4.5 and 3.0 days, respectively. The pupal weight and egg number were also significantly lower than those of the control. For C0030.3.5, it could control 1 st–5 th instar larvae effectively. The mortality rates were all over 50% if 1 st–3 rd larvae were fed with this event. The pupal weight of 4 th–6 th instar larvae fed with Bt maize were only 53.9, 56.8 and 54.6%, respectively, compared to that of the control. The number of eggs laid was significantly less than the control. The results indicate that all three transgenic maize events exhibit the potential to provide effective control of early instar larvae of armyworm, which can be commercialized in future to control lepidoptera pests such as Asian corn borer and armyworm.     

江苏沿海地区Bt棉主栽品种的性状评价

室内饲养结果表明,与对照品种"苏棉9号"比较,4个Bt棉品种对棉铃虫的抗性都达到极显著水平;饲喂Bt棉组织,能使棉铃虫幼虫发育延缓、蛹期缩短和蛹重减轻;1～3龄棉铃虫幼虫对Bt棉的敏感程度高于4龄以上幼虫。田间调查结果表明,Bt棉田棉铃虫的虫量和蕾铃被害量与对照棉田差异极显著,其趋势与室内试验一致。在棉花品种的生育特性方面,4个Bt棉品种的株高和果枝数与"苏棉9号"相近;蕾铃数量及成铃率高于或接近于常规棉;各品种间生长发育指标的差异均达不到显著水平。按照供试的4个Bt棉品种在当地的抗虫性及丰产性状的优劣排序,依次为"鲁棉研15">"中棉所29">"南抗3号">"科棉1号"。     

转基因抗虫棉对棉铃虫抗虫性研究

用转Bt、CPTI基因的抗虫棉材料进行抗虫性试验。研究结果表明 :1 导入不同外源基因的转基因抗虫棉因其杀虫机理不同而对棉铃虫抗性存在差异 ;2 随种植世代一代、二代、三代、五代其对棉铃虫的抗虫性下降 ;3 转基因抗虫棉的蛋白毒性在棉铃虫体内具有一定的残效 ;4 棉铃虫四龄以上幼虫对转Bt基因抗虫棉产生明显的抗性。     

转Bt基因棉抗虫性的室内鉴定技术

从棉花种植、供试棉株器官选择、棉铃虫饲养、标准试虫选择、室内生测方法、抗性级别评价标准等方面 ,系统地总结了转 Bt基因棉抗虫性的室内鉴定技术。以从美国引进的转 Bt基因棉“保铃棉 32 B”为参考 ,对我国自行培育的第一个转 Bt基因棉“品种国抗棉 1号”的抗虫性进行了较系统的比较鉴定。     

Field Evaluation of the Asian Corn Borer Control in Hybrid of Transgenic Maize Event MON 810

In this study,a transgenic Bt maize hybrid(event MON 810 from Monsanto Company)expressing Cry1Ab protein derived from Bacillus thuringiensis(Bt)and its negative isoline hybrid were evaluatrial. Maize plants were artificially infested with neonate larvae of Asian corn borer at the mid-whorl(firstgeneration),pre-tassel(first-and/or second-generation),and silk(second-generation)growth stages.The transgenic Bt maize hybrid sustained significantly less leaf feeding damage(rating 1.0±0.0)than its negative isoline control(rating 7.3±0.1).With the Bt maize,1.3-6.8%of plants were damaged by corn borer tunneling with＜0.5 cm tunneling per stalk under different levels of infestation,compared with 100%of plants damaged with 9.3-25.0 cm tunneling per stalk for the negative isoline control. On average,transgenic Bt maize hybrids had only 0.01-0.05 tunnels per stalk and no stems were broken.In contrast,the negative isoline control had 3.11-8.36 tunnels per stalk and 31.2-73.9% of stems broken.Yields were significantly higher in trahsgenic Bt maize than in the control. These results demonstrate that transgenic Bt maize can significantly minimize yield losses caused by the Asian corn borer through resistance to the first-and second-generation larvae.     

Ovipositional responses of Spodoptera frugiperda on host plants provide a basis for using Bt-transgenic maize as trap crop in China

Spodoptera frugiperda, the pest fall armyworm(FAW), is widespread in more than 100 countries. To date, planting insectresistant transgenic crops is one of the main control methods in its native countries. In this study we evaluated Bt-transgenic maize(Bt maize) and non-transgenic(conventional) maize and six other host plants in greenhouse pot experiments and field trials for oviposition preference by the Chinese populations of FAW. In laboratory trials, female moths preferred to oviposit on maize with no significant preference between conventional and Bt maize. However, after conventional and transgenic maize were exposed to FAW larvae and damaged, oviposition was significantly higher on transgenic maize than on the conventional one. Field trials showed that for plants less damaged at an early stage(seedling stage), oviposition of FAW on transgenic and conventional maize was significantly higher than that on wheat, sorghum, foxtail millet, peanut and soybean while showing no significant difference between transgenic or conventional maize. FAW adults mainly laid eggs on Bt maize, while the larval density and leaf damage rating or percentage of damaged plants were significantly lower than on conventional maize. Larval density and its damage on conventional maize were significantly higher than that on Bt maize and the other five hosts. Thus, maize is a highly preferred and suitable host for S. frugiperda feeding and ovipositing, and Bt maize can be used as trap crop to protect other crops.     

南疆棉区转Bt基因棉对棉铃虫抗性表达及对节肢动物的影响

2000－2001年在新疆喀什叶城县研究了转Bt基因棉MD－80不同发育阶段对棉铃虫的抗性表达和棉田节肢动物群落。结果表明：1）转Bt基因棉棉叶对棉铃虫初孵幼虫有2个抗性高峰期5月中下旬和7月底，抗虫性分别为94．5％和83．3％，8月份抗性最低（22．7％），而河南的研究表明8月份正是第2个抗性高峰，抗虫效果高达93．8％；2）7月上旬棉株不同器官抗棉铃虫的强弱依次为：棉苞叶（96．7％），棉蕾（74．2％），花瓣（60％），棉叶（50．2％），棉铃（30％），花蕊（26．8％）；3）转Bt基因棉对不同龄期棉铃虫抗性随着龄期的增大而降低；4）节肢动物群落多样性，均匀度顺序依次为普通棉对照田（不进行任何防治，0.7706和0.1883),Bt棉药防田（使用化学农药防治害虫，0．3968和0．0931），Bt棉自控田（仅依靠自然天敌控制害虫，0．2211和0．0549），优势集中性依次为Bt棉自控田（0．9264），Bt棉药防田（0．8625），普通棉对照田（0．6881），表明普通棉对棉田的节肢动物群落最稳定，Bt棉药防田次之，Bt棉田自控田最差。     

Selection,effective dominance,and completeness of Cry1A.105/Cry2Ab2 dual-protein resistance in Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae)

In the U.S., Helicoverpa zea (Boddie) is a major pest targeted by both transgenic maize and cotton expressing Bacillus thuringiensis (Bt) proteins. Resistance of insect to Bt maize and cotton containing cry1A and cry2A genes has widely occurred in the U.S. In this study, two trials were performed to investigate larval survival and development of a Cry1A.105/Cry2Ab2 dual-protein resistant (VT2P-RR), a susceptible, and an F₁ heterozygous (VT2P-RS) populations of H. zea on ears of nine Bt and three non-Bt maize hybrids. The Bt maize hybrids evaluated represent five common pyramided traits expressing two or three of the Cry1A.105, Cry1Ab, Cry1F, Cry2Ab2, and Vip3Aa20 proteins. In the laboratory, neonates of the three H. zea populations were inoculated on silks of ears collected from maize at R1–R2 plant stages; and larval survivorship was checked 10 d after neonate release. All three insect populations survived normally on non-Bt maize ears. Varied numbers of VT2P-RR and VT2P-RS survived on ears of Cry1A.105/Cry2Ab2 maize, while all larvae of the three populations died or could not develop on ears of Vip3Aa20-expressing maize. The results demonstrated that the dual-protein resistant H. zea was not cross-resistant to Vip3Aa20-expressing maize, and thus traits with vip3Aa20 gene should be effective to manage Cry1A.105/Cry2Ab2-resistant H. zea. The resistance in VT2P-RR was determined to be incomplete on Cry1A.105/Cry2Ab2 maize. The effective dominance levels varied greatly, from recessive to incompletely dominant, depending on maize hybrids and trials, suggesting that proper selection of maize hybrids could be important for mitigating the Cry1A.105/Cry2Ab2 resistance. The data generated should aid in modeling multiple-protein Bt resistance in H. zea.