转基因抗虫棉苗期氮代谢

以3种不同转基因抗虫棉及其亲本对照为材料,研究了盆栽条件下不同品种棉花苗期氮代谢特征。结果表明与非转基因棉花比较,转Bt基因棉Z30叶片内的硝酸还原酶活性、肽酶活性、游离氨基酸含量均没有明显变化,但转氨酶活性显著增加(增幅为14.03%),可溶性蛋白含量显著减少(降幅为26.29%)。双价转基因棉花CCRI41叶片内除可溶性蛋白含量没有明显变化,其它所测指标均发生了显著的改变。双价转基因棉花SGK321叶片内硝酸还原酶活性、转氨酶活性、氨基酸含量没有明显变化,但肽酶活性和可溶性蛋白含量均显著增加(增幅分别为7.01%和121.32%)。随着转入基因的多样化,其可能引发转基因棉花产生的非预期效应更加不确定与复杂。     

高温胁迫对Bt棉铃壳中Bt蛋白含量及氮代谢的影响

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.     

转Bt基因稻谷对小鼠生理与生殖的影响

目的:通过对小鼠饲以Bt转基因稻谷,观察Bt转基因稻谷对小鼠的生理与生殖能力的影响,为评价Bt转基因稻谷的安全性提供科学依据.方法:将雌、雄昆明小鼠48只分开饲养,各按体重随机分为转基因稻谷组和非转基因稻谷组,饲以对应的稻谷进行90天喂养试验,检测相关生理与生殖指标.结果:与非转基因稻谷组相比,饲以Bt转基因稻谷组小鼠...     

Risk assessment and ecological effects of transgenic Bacillus thuringiensis crops on non-target organisms

The application of recombinant DNA technology has resulted in many insect-resistant varieties by genetic engineering (GE). Crops expressing Cry toxins derived from Bacillus thuringiensis (Bt) have been planted worldwide, and are an effective tool for pest control. However, one ecological concern regarding the potential effects of insect-resistant GE plants on non-target organisms (NTOs) has been continually debated. In the present study, we briefly summarize the data regarding the development and commercial use of transgenic Bt varieties, elaborate on the procedure and methods for assessing the non-target effects of insect-resistant GE plants, and synthetically analyze the related research results, mostly those published between 2005 and 2010. A mass of laboratory and field studies have shown that the currently available Bt crops have no direct detrimental effects on NTOs due to their narrow spectrum of activity, and Bt crops are increasing the abundance of some beneficial insects and improving the natural control of specific pests. The use of Bt crops, such as Bt maize and Bt cotton, results in significant reductions of insecticide application and clear benefits on the environment and farmer health. Consequently, Bt crops can be a useful component of integrated pest management systems to protect the crop from targeted pests.     

转基因(Cry1Ac)抗虫棉对土壤微生物的影响

对不同种植年限的转基因(Cry1Ac)抗虫棉田土壤中主要微生物数量变化进行了测定,结果表明：（1）种植转基因抗虫棉后对土壤微生物细菌、放线菌和真菌数量的影响趋势基本相似;（2）种植抗虫棉1年后,土壤中细菌、放线菌、真菌数量将有所增加,连续4年达到高峰,然后数量开始下降,连续种植7年后,棉田微生物数量接近于种植1年的棉田;（3）种植1年后又种植非转基因棉花的棉田,土壤微生物数量低于种植1年抗虫棉的棉田,与种植非转基因棉的数量无明显差异。由此可见,种植转基因抗虫棉对土壤微生物数量有一定的影响。     

Climatic limits of pink bollworm in Arizona and California: effects of climate warming

The distribution and abundance of pink bollworm (Pectinophora gossypiella Saunders (PBW)) in cotton in Arizona and California was examined using a validated weather-driven, physiologically based demographic model of cotton and PBW integrated into a geographic information system (GIS). Survival of diapause larvae during winter as affected by low temperatures is a key factor determining the range of PBW. Winter survival was estimated using data from Gutierrez et al. (Can. Entomol. 109 (1977) 1457) and Venette et al. (Environ. Entomol. 29 (5) (2000) 1018). The model was run continuously over the period 1 January 1995 to 31 December 2003 using observed weather data from 121 locations. Three output variables were mapped as measures of PBW persistence: over-winter survival of diapause PBW larvae, cumulative daily PBW larval densities over the season, and the number of diapause larvae produced during the season. The distribution of pink bollworm is predicted to be restricted to the relatively frost-free cotton growing areas of Arizona and Southern California where it currently reaches pest status. The model predicts that extension of PBW's range into the Central Valley of California is unlikely. The analysis questions the efficacy of an ongoing area-wide effort to prevent the establishment of PBW in the Central Valley of California. Four global warming scenarios were examined to estimate the effects on the potential geographic range of PBW. Average observed daily temperatures were increased 1.0, 1.5, 2.0 or 2.5 °C, respectively, in the four scenarios. Scenarios with average increases of 1.5–2.5 °C predicted that the range of PBW would expand into the Central Valley of California and the severity of the pest would greatly increase in areas of current infestation.     

Microbial control of cotton pests. Part I: Use of the naturally occurring entomopathogenic fungus Aspergillus sp. (BC 639) in the management of Creontiades dilutus (Stal) (Hemiptera: Miridae) and beneficial insects on transgenic cotton crops

The development and adoption of transgenic (Bt) crops that express the Bacillus thuringiensis (Bt) toxin has reduced the use of synthetic insecticide on transgenic crops to target Helicoverpa spp., the major insect pest of cotton in Australia. However, it has also increased the threat posed by sucking pests, particularly Creontiades dilutus (green mirid), which are unaffected by the Bt toxins in transgenic cotton crops. Here we report the efficacy of the entomopathogenic fungus Aspergillus sp. (BC 639) in controlling the infestation of transgenic cotton crops by C. dilutus and promoting interactions of transgenic cotton with beneficial insects. The results showed that the number of C. dilutus adults and nymphs recorded on plots treated with 1000, 750, 500, 250 ml/ha BC 639 fungus formulation were the same as on plots treated with the recommended concentration of the commercial insecticide Fipronil. The fungus was found to have minimal effect on predatory insects compared with Fipronil and was most effective against C. dilutus when applied at the rate of 500 ml/ha (equivalent to 50 g spores/ha). At this rate, the fungus was as effective as Fipronil for controlling C. dilutus populations and ensured the survival of predatory beetles, lacewings and spiders compared with Fipronil treatment. The yield from fungus-treated plots was 5.24 bales per acre compared with 5.40 and 3.88 bales per acre for Fipronil-treated and unsprayed plots, respectively. The ability of the BC 639 strain to control C. dilutus infestations of transgenic cotton crops while conserving beneficial insect populations suggests its potential for supplementing integrated pest management programs to reduce the use of synthetic insecticides for transgenic cropping systems.     

抗虫基因研究及在芸薹属作物上的应用

芸薹属作物属十字花科,包括多种重要的蔬菜和油料作物。该类作物易受病虫害侵袭,造成品质和产量严重受损。化学方法防治害虫不仅破坏环境而且费用昂贵,所以培育抗虫品种成为既经济又环保的措施之一。但由于目前抗虫资源匮乏,难以通过常规育种培育出抗虫的品种,植物基因工程技术的应用,能加快育种进程,提高育种效率。简要介绍近年来抗虫基因的发掘及其在芸薹属中的应用进展。     

转cry1Ac＋cry2Ab基因棉与转cry1Ac＋剧咯邢基因棉荒地的生存竞争能力

【背景】此研究为“十二五”转基因生物新品种培育国家项目中创建新的转基因棉花品种环境安全评价技术而设。【方法】以转双价双成抗虫基因（cry1Ac＋cry2Ab）棉和转双价抗虫、抗除草剂基因（cry1Ac＋肼强阳）棉为观察品种,非转基因棉赣棉11号为对照品种,在荒地用撒播和3cm深度播种2种方式,于2011年5月一2012年3月对棉花出苗率、株高、生育进程、棉吐絮瓣数、絮瓣脱落率、自生苗等生存竞争能力进行比较,检测、评价其杂草化的风险,并探讨、验证检测技术的可行性。【结果】在荒地条件下,以2种方式播种的转cry1Ac＋cry2Ab基因棉和转cry1Ac＋EP5P5基因棉与非转基因棉相比,上述各项指标的竞争能力总体上未表现显著优势。【结论与意义】转cry1Ac＋cry2Ab基因棉和转cry1Ac＋EPSPS基因棉在荒地条件下生长无杂草化风险。同时,研究证明,在荒地自然生态条件下,可以采用撒播和3cm深度播种方法检测新的转基因棉花品种在生存竞争能力上的杂草化风险,在测评上有互为参照效应,为定性评价新的转基因棉花品种的杂草化风险提供了保障。