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1.
转基因通过基因漂移可以渐渗到作物的野生近缘种,由此而导致的环境风险是全球广泛关注的生物安全问题.有3个关键因素可以决定环境风险的程度:特定空间距离的转基因漂移频率,转基因在野生近缘种中的表达水平,以及转基因为野生近缘种群体带来的适合度效应.本文将根据现有研究结果,从上述3方面对转基因漂移到非转基因栽培稻、杂草稻和野生稻造成的潜在环境影响进行回顾.栽培稻品种之间的基因漂移频率很低,可以通过空间隔离或其他方法使其降低到可忽略的水平.在共同分布的环境中,栽培稻基因(包括转基因)向杂草稻和野生稻的漂移不可避免.尽管抗虫转基因(Bt或Bt/CpTI)在栽培稻和野生近缘种杂交后代中可以正常表达,但由于在低虫压环境中,抗虫转基因不会明显改变野生近缘种的适合度,抗虫转基因漂移所造成的环境影响十分有限.因此对基因漂移而言,抗虫转基因栽培稻的商品化种植应该比较安全.然而,抗除草剂转基因渐渗到杂草稻或野生稻会改变群体的适合度,可能会引起不可预测的环境后果. 相似文献
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转基因技术研发为提高我国水稻产量和减少劳动力投入提供了巨大机遇。我国对转基因水稻研发进行了大量的投入,目前已培育了具有不同新性状的转基因水稻品系,许多品系已进入生物安全评价阶段。风险评价对转基因水稻的安全生产至关重要,是其商品化生产之前必须解决的问题,其中包括转基因逃逸及其潜在环境影响。对水稻抗虫转基因逃逸及其潜在环境风险的评价包括3个重要环节:(1)通过田间试验和模型模拟检测转基因漂移到非转基因栽培稻及其野生近缘种的频率;(2)检测转基因在栽培稻和野生近缘种后代中的表达;(3)确定转基因对野生近缘种群体适合度和进化潜力的影响。大量研究表明,在近距离的空间范围内栽培稻品种之间的基因漂移频率很低(〉0.1%),但栽培稻与其野生近缘种的基因漂移频率变异很大。进一步研究还表明,Bt抗虫转基因在栽培稻与普通野生稻后代中均能正常表达,但在其不同生长阶段,表达量有很大变异。在有较高水平的害虫虫压下,含有抗虫转基因的栽培稻及野生近缘种杂交后代与不含转基因的对照相比,抗虫性显著提高且适合度利益明显;但是,在虫害发生水平较低时,含有抗虫转基因的群体与不含抗虫转基因的群体相比没有显著的适合度优势。综上,转基因逃逸到非转基因水稻的频率极低,并且可以通过空间隔离阻断其逃逸。虽然抗虫转基因向杂草稻以及与栽培稻距离较近的野生稻群体的逃逸无法避免,但是野生稻和杂草稻群体周围环境中的总体虫压较低,所以基因漂移带来的环境影响应十分有限。 相似文献
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随着转基因技术的迅速发展, 越来越多的转基因作物被培育出来。转基因作物的外源转基因通过花粉传播向非转基因作物的漂移, 会影响非转基因作物品种的种子纯度, 从而可能导致一系列生物安全问题。为了研究转基因栽培水稻(Oryza sativa)中的外源转基因通过花粉介导向非转基因水稻品种逃逸的可能性及其频率, 我们选用3个含双价抗虫基因(Bt/CpTI)的转基因水稻品系及其相对应的非转基因水稻亲本品种(近等基因系)进行了转基因漂移的实验。为了获取在近距离状况下转基因水稻与非转基因水稻品种之间的转基因漂移频率, 采用了转基因与非转基因水稻品种间隔种植的栽培方式, 分别在福建省福州市和海南省三亚市的转基因环境安全实验地进行实验, 并利用潮霉素抗性筛选标记基因来鉴定转基因和非转基因稻的杂种。共检测了从非转基因水稻品种随机收获的70,056颗种子, 以此计算转基因漂移频率。结果表明, 在相邻种植的情况下, 由这3个转基因水稻向对应的非转基因水稻品种的转基因漂移的频率比较低(0.275–0.832%)。如此近距离条件下获得的低转基因漂移频率表明, 对于严格自花授粉的水稻而言, 通过一定的隔离措施, 能有效地降低由花粉介导的转基因漂移导致的非转基因种子混杂。 相似文献
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Bt/CpTI转基因稻及其非转基因亲本对照在间隔种植条件下的转基因漂移 总被引:11,自引:1,他引:10
随着转基因技术的迅速发展,越来越多的转基因作物被培育出来。转基因作物的外源转基因通过花粉传播向非转基因作物的漂移,会影响非转基因作物品种的种子纯度,从而可能导致一系列生物安全问题。为了研究转基因栽培水稻(Oryzasativa)中的外源转基因通过花粉介导向非转基因水稻品种逃逸的可能性及其频率,我们选用3个含双价抗虫基因(Bt/CpTI)的转基因水稻品系及其相对应的非转基因水稻亲本品种(近等基因系)进行了转基因漂移的实验。为了获取在近距离状况下转基因水稻与非转基因水稻品种之间的转基因漂移频率,采用了转基因与非转基因水稻品种间隔种植的栽培方式,分别在福建省福州市和海南省三亚市的转基因环境安全实验地进行实验,并利用潮霉素抗性筛选标记基因来鉴定转基因和非转基因稻的杂种。共检测了从非转基因水稻品种随机收获的70,056颗种子,以此计算转基因漂移频率。结果表明,在相邻种植的情况下,由这3个转基因水稻向对应的非转基因水稻品种的转基因漂移的频率比较低(0.275–0.832%)。如此近距离条件下获得的低转基因漂移频率表明,对于严格自花授粉的水稻而言,通过一定的隔离措施,能有效地降低由花粉介导的转基因漂移导致的非转基因种子混杂。 相似文献
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转基因水稻外源基因的漂移研究 总被引:2,自引:0,他引:2
转基因水稻基因漂移可能带来环境安全性问题。利用农杆菌介导,把hpt基因转化水稻品种,通过后代筛选,以稳定遗传的含单拷贝转化株系为转基因花粉供体材料,研究转基因水稻向非转基因水稻不育系和常规稻(花粉受体)的外源基因漂移频率。结果表明,相邻种植时转基因水稻向雄性不育系品种的漂移频率为31.74%。随距离的增加漂移频率明显下降,在26m处仍能够检测到含外源基因个体的存在,并且在距离4m处出现一个漂移频率的升高;转基因水稻向常规品种的漂移频率则明显低于不育系,一般在2.0%以下,随距离的增加也呈现下降的趋势,在18m处开始无法检测到含外源基因的个体。 相似文献
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风向因素对转基因抗虫棉花基因漂移效率的影响 总被引:3,自引:0,他引:3
在转基因作物获准进行环境释放并实行大面积商品化推广的同时,基因漂移所引起的生态环境安全问题不容忽视。本研究以含有双价抗虫基因(Bt/CpTI)的转基因棉花SGK321为花粉供体材料,以常规非转基因棉花品种石远321、中棉35、吉扎1号为花粉受体材料,在温室中人工创造定向风和非定向风条件,应用PCR与蛋白检测相结合的方法,检测外源基因发生基因漂移的效率。结果表明:随着与转基因棉花SGK321距离的增加,外源基因转移至非转基因棉花的基因漂移频率呈现波动性变化。在定向风处理中,基因漂移频率在距离转基因棉花6.4 m处达到峰值33.33%,在测定范围内基因漂移最远距离为25.6 m;而在非定向风处理中,基因漂移频率在距离转基因棉花12.8 m处达到峰值36.67%,在测定范围内基因漂移最远距离为36 m。非定向风可显著提高转移至海岛棉吉扎1号的基因漂移频率。外源基因从SGK321转移至其非转基因亲本石远321的基因漂移频率显著高于转移至陆地棉中棉35和海岛棉吉扎1号的漂移频率。本研究可为转基因棉花的生态安全性分析提供一定的理论参考价值。 相似文献
10.
转基因抗除草剂油菜对近缘作物的基因漂移 总被引:8,自引:0,他引:8
以转基因抗除草剂油菜 Q3和 HCN- 19为花粉供体材料 ,油菜近缘作物为花粉受体材料 ,在自然授粉条件下研究甘蓝型油菜与芸薹属近缘作物间的基因漂移频率。结果表明 ,油菜对芸薹属 6个种甘蓝、黑芥、埃芥、芥菜型油菜、白菜型油菜和甘蓝型油菜的基因漂移率分别为 0、0 .0 2 4 %~ 0 .2 4 3%、 0 .0 2 8%~ 0 .0 92 %、 0 .10 9%~ 0 .95 1%、 0 .4 79%~ 0 .879%、 1.2 5 2 %~2 .191%。且基因漂移频率受多种因素影响 ,其中与杂交亲和性、花期同步率、种植面积等高度相关。通过花粉将抗除草剂基因漂移给近缘作物 ,油菜是需要特别关注的作物 相似文献
11.
BACKGROUND AND AIMS: Transgene escape through gene flow from genetically modified (GM) crops to their wild relative species may potentially cause environmental biosafety problems. The aim of this study was to assess the extent of gene flow between cultivated rice and two of its close relatives under field conditions. METHODS: Experiments were conducted at two sites in Korea and China to determine gene flow from cultivated rice (Oryza sativa L.) to weedy rice (O. sativa f. spontanea) and common wild rice (O. rufipogon Griff.), respectively, under special field conditions mimicking the natural occurrence of the wild relatives in Asia. Herbicide resistance (bar) and SSR molecular finger printing were used as markers to accurately determine gene flow frequencies from cultivated rice varieties to their wild relatives. KEY RESULTS: Gene flow frequency from cultivated rice was detected as between approx. 0.011 and 0.046 % to weedy rice and between approx. 1.21 and 2.19 % to wild rice under the field conditions. CONCLUSIONS: Gene flow occurs with a noticeable frequency from cultivated rice to its weedy and wild relatives, and this might cause potential ecological consequences. It is recommended that isolation zones should be established with sufficient distances between GM rice varieties and wild rice populations to avoid potential outcrosses. Also, GM rice should not be released when it has inserted genes that can significantly enhance the ecological fitness of weedy rice in regions where weedy rice is already abundant and causing great problems. 相似文献
12.
中国是水稻的起源中心之一,分布着丰富的野生种质资源.自转基因水稻获得安全证书以来,转基因水稻与其近缘野生种间的基因流受到广泛关注.本文对转基因水稻基因流的发生及其可能引起的生态学后果进行了综述和展望.认为转基因水稻能够与栽培稻、野生稻、杂草稻、稗草等成功杂交,但基因流发生频率较低且变化较大.基因流成功发生后,由于转基因水稻具转基因新性状而有适合度优势,转基因可能只通过少数几代就进入野生种群.当转基因植株进入野生种群并在自然条件下长期存在时,转基因植株与近缘野生种间的竞争关系和相对适合度将决定混合种群的动态变化.研究转基因水稻基因流的影响及其长期生态学后果对合理保护与利用野生种质资源具有重要意义. 相似文献
13.
Transgene flow to hybrid rice and its male-sterile lines 总被引:9,自引:0,他引:9
Gene flow from genetically modified (GM) crops to the same species or wild relatives is a major concern in risk assessment.
Transgenic rice with insect and/or disease resistance, herbicide, salt and/or drought tolerance and improved quality has been
successfully developed. However, data on rice gene flow from environmental risk assessment studies are currently insufficient
for the large-scale commercialization of GM rice. We have provided data on the gene flow frequency at 17 distances between
a GM japonica line containing the bar gene as a pollen donor and two indica hybrid rice varieties and four male-sterile (ms) lines. The GM line was planted in a 640m2 in an isolated experimental plot (2.4 ha), which simulates actual conditions of rice production with pollen competition.
Results showed that: (1) under parallel plantation at the 0-m zone, the transgene flow frequency to the ms lines ranged from
3.145 to 36.116% and was significantly higher than that to hybrid rice cultivars (0.037–0.045%). (2) Gene flow frequency decreased
as the distance increased, with a sharp cutoff point at about 1–2 m; (3) The maximum distance of transgene flow was 30–40 m
to rice cultivars and 40–150 m to ms lines. We believe that these data will be useful for the risk assessment and management
of transgenic rice lines, especially in Asia where 90% of world's rice is produced and hybrid rice varieties are extensively
used.
Shirong Jia, Feng Wang and Lei Shi contributed equally to this investigation. 相似文献
14.
Gene flow from genetically modified rice to its wild relatives: Assessing potential ecological consequences 总被引:4,自引:0,他引:4
Pollen-mediated gene flow is the major pathway for transgene escape from GM rice to its wild relatives. Transgene escape to wild Oryza species having AA-genome will occur if GM rice is released to environments with these wild Oryza species. Transgenes may persist to and spread in wild populations after gene flow, resulting unwanted ecological consequences. For assessing the potential consequences caused by transgene escape, it is important to understand the actual gene flow frequencies from GM rice to wild relatives, transgene expression and inheritance in the wild relatives, as well as fitness changes that brought to wild relatives by the transgenes. This article reviews studies on transgene escape from rice to its wild relatives via gene flow and its ecological consequences. A framework for assessing potential ecological consequences caused by transgene escape from GM rice to its wild relatives is discussed based on studies of gene flow and fitness changes. 相似文献
15.
Gene flow from herbicide-tolerant GM rice and the heterosis of GM rice-weed F2 progeny 总被引:1,自引:0,他引:1
Chun YJ Kim DI Park KW Kim HJ Jeong SC An JH Cho KH Back K Kim HM Kim CG 《Planta》2011,233(4):807-815
Gene flow from genetically modified (GM) crops to non-GM cultivars or weedy relatives may lead to the development of more
aggressive weeds. We quantified the amount of gene flow from herbicide-tolerant GM rice (Protox GM, derived from the cultivar Dongjin) to three cultivars (Dongjin, Aranghyangchal and Hwaseong) and a weedy rice line. Gene
flow frequency generally decreased with increasing distance from the pollen donor. At the shortest distance (0.5 m), we observed
a maximum frequency (0.039%) of gene flow. We found that the cultivar Dongjin received the greatest amount of gene flow, with
the second being weedy rice. Heterosis of F2 inbred progeny was also examined between Protox GM and weedy rice. We compared growth and reproduction between F2 progeny (homozygous or hemizygous for the Protox gene) and parental rice lines (GM and weedy rice). Here, transgene-homozygous F2 progeny was significantly taller and produced
more seeds than the transgene-hemizygous F2 progeny and parental lines. Although the gene flow frequency was generally low,
our results suggest that F2 progeny between GM and weedy relatives may exhibit heterosis. 相似文献
16.
This review discusses a multidisciplinary and multicomponent approach leading to the development and commercial release of
transgenic Costa Rican rice varieties tolerant to the herbicide gluphosinate ammonium. We describe the field evaluations of
the transgenic lines and their potential environmental impact, focusing on gene flow, particularly in relation to native wild
Oryza species and weedy rice, based on trials performed in compliance with the national regulatory requirements of the country.
We also present a socio-economic analysis of rice production in Costa Rica and the economic benefits of genetically modified
(GM) rice as well as an environmental risk-benefit analysis for the deployment of GM rice. Additionally, food safety evaluation,
intellectual property management, requirements for deregulation, and options for the commercialization of the new varieties
are discussed. We also present results from a national survey aimed at assessing the level of support for GM crops in Costa
Rica as this forms an integral component of our approach. Taken together, our results demonstrate that the adoption of these
genetically improved rice varieties will provide clear benefits to Costa Rican rice growers and consumers. 相似文献
17.
野生稻有利基因的发掘和利用 总被引:9,自引:0,他引:9
摘要: 野生稻作为栽培稻的野生亲缘种, 具有许多优良的性状和有利基因, 是栽培稻品种进一步改良的天然遗传种质资源库。其中, 野生稻对病虫害的抗性、对各种逆境的耐受性以及胞质雄性不育等, 已广泛应用于现代栽培稻的育种改良。文章综述了野生稻种质资源的有利性状及相应控制基因的发掘, 探讨了其在今后水稻育种中的应用潜力。 相似文献
18.
Wang F Yuan QH Shi L Qian Q Liu WG Kuang BG Zeng DL Liao YL Cao B Jia SR 《Plant biotechnology journal》2006,4(6):667-676
The introgression of transgenes into wild relatives or weeds through pollen-mediated gene flow is a major concern in environmental risk assessment of transgenic crops. A large-scale (1.3–1.8 ha) rice gene flow study was conducted using transgenic rice containing the bar gene as a pollen donor and Oryza rufipogon as a recipient. There was a high frequency of transgene flow (11%−18%) at 0–1 m, with a steep decline with increasing distance to a detection limit of 0.01% by 250 m. To our knowledge, this is the highest frequency and longest distance of gene flow from transgenic rice to O. rufipogon reported so far. On the basis of these data, an adequate isolation distance from both conventional and transgenic rice should be taken for in situ conservation of common wild rice. Meanwhile, there is no evidence of transgene introgression into barnyard grass, even when it has coexisted with transgenic rice containing the bar gene for five successive years. Thus, the environmental risk of gene flow to this weedy species is of little concern. 相似文献
19.
耐非生物胁迫转基因水稻的培育——现在和未来 总被引:1,自引:0,他引:1
环境胁迫严重降低了作物产量,日益减少的耕地和膨胀的人口对世界粮食安全造成了威胁。长期以来,改善作物的抗逆性一直是农业生产的主要目标。水稻是重要的粮食作物之一,培育具有抗逆性的水稻品种对全球的粮食生产将产生重要影响。在改善水稻的抗逆性方面,转基因比传统方法更有发展潜力。近年来,已有许多抗逆相关基因转入水稻并获得了一些提高抗逆性的转基因植株,文章重点讨论了耐非生物胁迫转基因水稻的研究进展。 相似文献