转cry1Ac+cry2Ab基因棉对棉田节肢动物群落的影响

以Bt棉和常规棉为对照,研究了转cry1Ac+cry2Ab棉对棉田节肢动物群落的影响。研究结果表明,转cry1Ac+cry2Ab棉田、转cry1Ac棉田和常规棉田节肢动物群落、害虫亚群落和天敌亚群落的结构与组成无明显差异;转cry1Ac+cry2Ab棉田刺吸类害虫、蛀食类害虫和食叶类害的数量均低于转cry1Ac棉田和常规棉田;转cry1Ac+cry2Ab棉田蜘蛛类、瓢虫类和捕食类天敌的数量均低于转cry1Ac棉田和常规棉田;转cry1Ac+cry2Ab棉田节肢动物群落、害虫亚群落和天敌亚群落的多样性指数与转cry1Ac棉田和常规棉田相比均无明显差异,说明转cry1Ac+cry2Ab棉田节肢动物群落、害虫亚群落和天敌亚群落的稳定性和转cry1Ac棉和常规棉相比均无明显差异。     

转cry1Ab/cry2Aj、cry1Ab/vip3DA玉米对棉铃虫、甜菜夜蛾和斜纹夜蛾的抗虫性评价

为评估转cry1Ab/cry2Aj、cry1Ab/vip3DA玉米对棉铃虫Helicoverpa armigera(Hübner)、甜菜夜蛾Spodoptera exigua(Hübner)和斜纹夜蛾Prodenia litura(Fabricius)的抗虫性,在室内测定了3个转cry1Ab/cry2Aj玉米品系和1个转cry1Ab/vip3DA玉米品系对3种害虫幼虫存活和生长发育的影响,研究了该系列Bt玉米不同组织器官对害虫的杀虫活性和控制效果。结果显示,棉铃虫初孵幼虫取食各品系Bt玉米叶片96h后死亡率为87.50%~90.00%,取食花丝和雌穗的幼虫96h后几乎全部死亡;甜菜夜蛾初孵幼虫取食各品系Bt玉米叶片、花丝和雌穗168h后死亡率为22.50%~68.33%,幼虫的生长发育受到明显抑制,体重抑制率达85.00%~95.00%;斜纹夜蛾初孵幼虫取食各品系Bt玉米叶片、花丝和雌穗96 h后死亡率显著高于非转基因亲本对照,168h后幼虫死亡率达90.00%以上。研究表明,转cry1Ab/cry2Aj和cry1Ab/vip3DA玉米品系对棉铃虫和斜纹夜蛾的初孵幼虫表现出较好的抗性,可以作为转多基因抗虫玉米育种的备选材料。     

转cry1Ab/cry1Ac基因水稻赣绿1号对田间稻纵卷叶螟和二化螟及其捕食性天敌的影响

为研究转cry1Ab/cry1Ac基因水稻赣绿1号对稻纵卷叶螟Cnaphalocrocis medinalis和二化螟Chilo suppressalis及其捕食性天敌的影响,采用剥查法和吸虫法,于2012—2013年在江西省南昌县调查了赣绿1号田间稻纵卷叶螟与二化螟的发生为害情况及其捕食性天敌拟环纹豹蛛Pardosa pseudoannulata和拟水狼蛛Pirata subpiraricus的种群动态。结果表明,与非转基因亲本9311水稻相比,在2012和2013年螟虫为害高峰期,赣绿1号田间稻纵卷叶螟百株虫量分别减少57.78头和27.78头,卷叶率分别降低20.46%和6.50%;二化螟百株虫量分别减少24.44头和152.22头,枯心/白穗率分别降低13.02%和14.20%。此外,赣绿1号与9311水稻田间拟环纹豹蛛和拟水狼蛛的种群动态趋势基本一致。研究表明,转cry1Ab/cry1Ac基因水稻赣绿1号能有效控制稻纵卷叶螟和二化螟,而对其捕食性天敌拟环纹豹蛛和拟水狼蛛无显著影响。     

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.     

银川平原麦蚜寄生蜂群落结构及其时间动态

在实际调查的基础上,研究了银川平原麦蚜寄生蜂群落结构组成。结果表明,银川平原麦蚜寄生蜂群落包括初寄生蜂和重寄生蜂两个亚群落,共22种,隶属4总科,7科13属。其中初寄生蜂12种,重寄生蜂10种。燕麦蚜茧蜂（Aphidius avenae）为优势种。并采用多样性指数（H′）、丰富度(S)、均匀度(E)及优势度(C)等指标对麦蚜寄生蜂的群落动态进行了初步分析。结果表明：5月份前初寄生蜂的多样性指数较大,重寄生蜂的多样性则在5月中旬开始上升,总群落在6月上旬多样性指数最高。     

转cry1Ab/vip3H基因水稻对非靶标害虫褐飞虱连续多代生长发育与繁殖的影响

实验室条件下,转cry1Ab/vip3H基因水稻G6H1对褐飞虱Nilaparvata lugens生长发育与繁殖的继代效应评价结果表明,不论是在苗期或是成株期,在各水稻品种上连续饲喂褐飞虱4代后,该虫各代的生长发育和繁殖参数都没有受到水稻品种的显著影响,即不论是在第1代、第2代还是第4代,取食G6H1与取食其非转基因亲本Xiushui 110相比,褐飞虱若虫的发育时间、成虫寿命和产卵量都没有显著差异。同时,2008年和2009年的田间调查结果表明,G6H1和Xiushui 110稻田间褐飞虱的若虫、成虫和成若虫总密度均无显著差异。     

转cry1F基因玉米花粉对腰带长体茧蜂存活和繁殖的影响

腰带长体茧蜂（Macrocentrus cingulum）是亚洲玉米螟（Ostrinia furnacalis）幼虫的主要寄生蜂,对亚洲玉米螟种群具有重要的控制作用。玉米花粉可以作为腰带长体茧蜂的补充营养。本研究利用转cry1F基因抗虫玉米花粉作为补充食物饲喂腰带长体茧蜂寄生亚洲玉米螟幼虫,研究其对腰带长体茧蜂存活和繁殖的影响,为转基因抗虫玉米的环境安全评价提供科学依据。结果表明,饲喂转cry1F基因抗虫玉米花粉后腰带长体茧蜂的寄生率、茧块重量、每茧块茧数、羽化率与饲喂对照玉米花粉相比无显著差异;在蜂蜜水+ Bt玉米花粉处理中虽然与对照玉米花粉处理相比雌蜂的寿命并没有显著差异,但雄蜂的寿命差异显著;在取食转cry1F基因抗虫玉米花粉的腰带长体茧蜂体内未检测到Bt蛋白成分。说明转cry1F基因抗虫玉米花粉对腰带长体茧蜂的存活和繁殖没有显著影响。     

转cry1Ab基因抗虫籼稻对非靶标害虫白背飞虱发育与繁殖的影响

为了比较2个转cry1Ab基因抗虫籼稻品系B1和B6对其非靶标害虫白背飞虱敏感性与其非转基因亲本对照嘉早935的差异，采用历期测定和产卵行为电子记录等方法分别测定了白背飞虱于B1和B6及嘉早935上的发育历期、产卵行为及繁殖力。结果表明，该飞虱以B1和B6为食时，其雌雄若虫总发育历期均显著长于对照，其中在B1上各延长了1．3和1．5天，B6延长了2．0和1．4天。产卵行为的电子记录结果表明，该飞虱在B1和B6上的产卵频次、一次产卵时间及总产卵时间与对照相比均无显著差异。在寄主植株可选择时，该飞虱有偏爱于B1上产卵，其上的产卵痕数、卵块数和总产卵量明显多于对照；而不嗜好于B6上产卵，其上的卵块及其卵粒数、总产卵量明显少于对照。然而，在寄主植株不可选择时，则未观察到这种差异。就卵孵化率而言，不论在寄主可选择还是不可选择时，与对照相比B1和B6对其均无显著的不利影响。     

转Bt cry1Ab基因水稻花粉对中华 草蛉成虫产卵和寿命的影响

用ELISA法测定了转Bt基因水稻克螟稻1号(KMD1)和克螟稻2号(KMD2)花粉中Cry1Ab含量.将转Bt基因水稻和其亲本对照秀水11(XS11)花粉加入到草蛉人工干粉饲料中,评价了对中华草蛉Chrysoperla sinica Tjeder成虫产卵和寿命等参数的影响.结果显示,转Bt基因水稻"克螟稻"花粉中表达cry1Ab杀虫蛋白,且表达量较高.分别用含5%KMD1、KMD2和XS11花粉的人工饲料饲喂中华草蛉初羽化成虫,发现两类Bt水稻花粉对该虫产卵前期、产卵量、产卵天数和成虫寿命等参数均无显著影响.人工饲料中水稻花粉的比例上升至20%和80%后,KMD1、KMD2和XS11花粉饲料处理中的草蛉均出现产卵前期延长、产卵量减少和产卵天数缩短的趋势,但在同一花粉比例下这些参数在3个花粉饲料处理间均无显著差异.结果表明,Bt水稻花粉中cry1Ab杀虫蛋白对该草蛉成虫产卵和寿命等参数无显著的负面影响.     

转cry1Ab基因粳稻对稻纵卷叶螟成虫产卵行为的影响

为评价转cry1Ab基因粳稻(KMD1和KMD2)对稻纵卷叶螟Cnaphalocrocis medinalis(Guenée)成虫产卵行为的影响,采用"Y"型嗅觉仪和笼罩以及田间试验等方法对稻纵卷叶螟成虫对转基因水稻的趋性以及其产卵选择性进行了研究,并利用固相微萃取和GC-MS技术测定了这2种Bt水稻及其对照亲本秀水11挥发物的组成及其相对含量。结果表明,稻纵卷叶螟成虫在"Y"型嗅觉仪和小型笼罩内对Bt水稻和对照亲本的选择性差异不显著,而在大型笼罩和田间条件下均显著趋向于在非转基因水稻上产卵,其中大田中稻纵卷叶螟在KMD1、KMD2和对照中的百叶卵量分别为2.20±1.28、1.00±0.77和5.60±2.16粒。水稻挥发物的组成及其相对含量在Bt水稻及其对照亲本之间差异不显著。表明相对于Bt水稻,在田间条件下稻纵卷叶螟成虫趋向于在非转基因水稻产卵,而水稻挥发物可能不是引起这种行为趋性的直接原因。     

转Cry1Ab/Ac基因水稻对稻田底栖动物群落的生态安全性

为探究转Bt基因抗虫水稻对稻田水生生物的安全性,以转Cry1Ab/Ac基因抗虫水稻华恢1号(HH1)为材料,其非转基因水稻亲本明恢63(MH63)为对照,以底栖动物群落为指示生物,运用群落学方法研究了湖南湘潭转Bt水稻对稻田底栖动物群落的影响。结果显示,2012年在HH1与MH63稻田中,分别采集到底栖动物37种和38种,二者共有物种31种,群落物种相似度为0.8267,优势种相似度为0.8235;2013年在HH1与MH63稻田中分别采集到底栖动物40种和41种,二者共有物种33种,群落物种相似度为0.8148,优势种相似度为0.9231;2012与2013年在HH1与MH63稻田生境中,物种丰富度、个体数量、群落多样性指数、均匀性指数与优势集中性指数的时间动态趋势一致,且均无显著差异。研究表明,连续2年稻田种植转Cry1Ab/Ac基因抗虫水稻HH1,在群落水平上对湖南湘潭地区稻田底栖动物无显著影响。     

Bt水稻对主要非靶标害虫和蜘蛛优势种田间种群动态的影响

研究了2个转cry1Ab cry1Ac杂合基因籼稻品系TT9-3和T19-4对主要非靶标害虫飞虱、叶蝉以及捕食性蜘蛛优势种田间种群动态的影响。结果表明,Bt稻与亲本对照(IR72)田间白背飞虱和黑尾叶蝉成虫的虫口密度在整个水稻生育期间无显著差异,而若虫密度有一定的不同。TT9-3稻田中白背飞虱和黑尾叶蝉若虫密度分别于移栽后早中期和中后期显著高于对照;TT9-4与对照间无显著差异。Bt水稻与亲本对照间锥腹肖蛸、四斑锯螯蛛、食虫沟瘤蛛、拟环纹豹蛛及拟水狼蛛种群数量动态趋势相似,数量上大多无显著差异。综合分析认为,Bt水稻对稻田优势蜘蛛基本上无明显的负影响。     

Developmental studies of transgenic maize expressing Cry1Ab on the African stem borer, Busseola fusca; effects on midgut cellular structure

BACKGROUND: Busseola fusca is a major pest of maize in Africa but unfortunately is difficult to control using chemical insecticides. Insect‐resistant transgenic crops may provide an alternative viable strategy to control this pest. RESULTS: Recombinant Cry1Ab (1%) reduced larval weight by 60% over the trial period, while larval weight in the control group increased by 25%; no effects on mortality were observed. Insect survival, developmental rate and pupal and adult weight were significantly reduced (P < 0.05) on maize expressing Cry1Ab (MON810) compared with the non‐transformed parental line. These differences were more pronounced with second‐instar larvae than with third‐instar larvae. Leaf area consumed by Bacillus thuringiensis (Bt)‐fed larvae was significantly lower (0.5 cm² larva^?1 day^?1) compared with the area consumed by control‐fed insects (3.3 cm² larva^?1 day^?1). EM studies revealed that consumption of Bt maize deleteriously affected gut integrity. Effects were observed in columnar cells of the midgut epithelium, with the cytoplasm becoming highly vacuolated; the microvilli were disorganised, the mitochondria were abnormal and there was an increase in the number of lysosomal bodies. The rough endoplasmic reticulum had also become dilated. CONCLUSION: This study confirms the potential for Bt maize, when used as part of an IPM programme, for control of B. fusca. Copyright © 2011 Society of Chemical Industry     

Marker‐free,tissue‐specific expression of Cry1Ab as a safe transgenic strategy for insect resistance in rice plants

BACKGROUND: Rice is the major food resource for nearly half of the global population; however, insect infestation could severely affect the production of this staple food. To improve rice insect resistance and reduce the levels of Bt toxin released into the environment, the Cry1Ab gene was conjugated to the rice rbcS promoter to express Bt toxin in specific tissues of transgenic plants. RESULTS: Eight marker‐free, T₂ lines were separated from the T₀ cotransformants. Using RT‐PCR, high levels of Cry1Ab expression were detected in the leaf but not in the seed. The Cry1Ab protein level ranged from 1.66 to 3.31 µg g^?1 in the leaves of four transgenic lines, but was barely detectable in their seeds by ELISA. Bioassays showed that the mortality rate of silkworm larvae feeding on mulberry leaves dipped in transgenic rice flour and pollen was less than that of the positive control (KMD), and that their average weight was higher than that of KMD, suggesting that the Cry1Ab protein was not expressed in the seed and pollen. CONCLUSION: The transgene conferred a high level of resistance to insects and biosafety to the rice plants, which could be directly used in rice breeding. Copyright © 2012 Society of Chemical Industry