Shared flowering phenology, insect pests, and pathogens among wild, weedy, and cultivated rice in the Mekong Delta, Vietnam: implications for transgenic rice
Shared flowering phenology, insect pests, and pathogens among wild, weedy, and cultivated rice in the Mekong Delta, Vietnam: implications for transgenic rice
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DOI：
10.1051/ebr:2008011
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发表时间：
2008-04-01
期刊：
影响因子：
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通讯作者：
Snow, Allison A.
中科院分区：
文献类型：
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作者：
Cohen, Michael B.;Arpaia, Salvatore;Snow, Allison A.
在野生和杂草亲缘关系与作物共存的国家，许多转基因水稻品种正在开发中。为了评估与花粉介导的转基因传播相关的可能风险，我们在越南进行了一项为期两年的调查，以检查水稻(Oryza sativa L.)、杂草水稻(O.sativa)和野生稻(O.rufipogon Griff.)的重叠花期，所有这些水稻都是可育的。我们调查了湄公河三角洲北部和南部两个地区的种群，以及每个地区三个栖息地的三个地点：淡水、咸水和酸性硫酸盐土壤。杂草水稻经常与邻近的栽培水稻同时开花。野生稻的开花更具季节性，通常在11月和12月达到顶峰。在所有盐碱地和一半的酸性硫酸盐地，野生稻的开花高峰期与相邻稻田重叠。野生水稻较长的花期确保了在淡水生境中也有可能实现作物到野生物种的基因流动。我们的第二个目标是确定野生和杂草水稻种群是否暴露在未来转基因可能针对的害虫面前，这可能会提供健康益处。这些种群与栽培稻有许多共同的病原菌和食草虫种类(叶蝉、蝗虫、蟋蟀、飞虱、稻纵卷叶蛾、二化螟、纹枯病、稻瘟病、白叶枯病和褐斑病)。食叶害虫和蝗虫危害是三种类型水稻上最常见的昆虫取食危害。指示物种分析表明，大多数昆虫食草动物与特定的生境有关，这表明了广泛的地理抽样对转基因水稻风险评估的重要性。这些调查数据和栽培水稻基因流动的强烈可能性表明，需要进一步研究转基因特性(如抗虫性)对野生和杂草水稻丰度的影响。
Many varieties of transgenic rice are under development in countries where wild and weedy relatives co-occur with the crop. To evaluate possible risks associated with pollen-mediated transgene dispersal, we conducted a two-year survey in Vietnam to examine overlapping flowering periods of rice (Oryza sativa L.), weedy rice (O. sativa), and wild rice (O. rufipogon Griff.), all of which are inter-fertile. We surveyed populations in two regions of the Mekong Delta, northern and southern, and at three sites in each of three habitats per region: fresh water, saline water, and acid sulfate soil. Weedy rice frequently flowered simultaneously with neighboring cultivated rice plants. Flowering was more seasonal in wild rice and often peaked in November and December. Peak flowering times of wild rice overlapped with adjacent rice fields at all of the saline sites and half of the acid sulfate sites. The longer flowering season of wild rice ensured that crop-to-wild gene flow was possible in fresh water habitats as well. Our second objective was to determine whether wild and weedy rice populations are exposed to pests that could be targeted by future transgenes, which may then provide fitness benefits. These populations shared many pathogen and insect herbivore species with cultivated rice (leaffolder, locust, cricket, planthoppers, rice bug, stem borer, sheath blight, blast, bacterial leaf blight, and brown spot). Damage by leaffolders and locusts was the most frequently observed insect feeding damage on all three rice types. Indicator species analysis revealed that most of the insect herbivores were associated with particular habitats, demonstrating the importance of broad geographic sampling for transgenic rice risk assessment. These survey data and the strong likelihood of gene flow from cultivated rice suggest that further studies are needed to examine the effects of transgenic traits such as resistance to pests on the abundance of wild and weedy rice.