转基因水稻外源基因向近缘种群漂流和渐渗的研究进展

Advance in understanding gene flow and introgression from transgenic rice to its related species

水稻是我国最重要的粮食作物之一,我国有8亿以上的人口以稻米作为主食。但在水稻生产中,由于病、虫、草害及不良气候等逆境因子的影响,严重制约了水稻的高产、稳产。转基因生物技术的迅速发展,为水稻抗性育种提供了新途径。自20世纪80年代以来,我国全方位地开展了转基因水稻的研发,目前已经培育出大量的抗病、抗虫、抗除草剂和抗逆的转基因水稻品种,这将为提高我国水稻的生产力和确保粮食安全做出重要的贡献。但转基因水稻的基因漂流及其可能带来的生物安全问题备受关注。已有报道证明,外源转基因可以通过异交向非转基因品种和野生近缘种漂流。在不同的试验条件下,抗除草剂基因有0.05%～0.53%逃逸的可能,其向不育系的最大漂移频率可达4.518%。抗虫基因向相邻非转基因水稻的平均漂移频率最高为0.875%。因此,本文对水稻与其近缘野生种的杂交情况,转基因水稻外源基因向非转基因品种、野生近缘种以及野生非近缘种的漂流和渐渗及其潜在的生态环境风险等方面进行了简要分析,并对转基因水稻的发展进行了展望,以期为转基因水稻的安全应用提供参考。

Rice is one of the most important food crops in China, a staple food for over 800 million people. Diseases, pests, weeds, harsh climate as well as other stress conditions severely retard high and stable rice yields. Transgenic technology has offered a novel means to breed rice varieties and cuhivars against these stresses. In China, many GM （genetically modified） varieties and cultivars of rice resistant to some diseases, pests, weeds, and abiotic stresses have been generated since the 1980s, which have the potential to improve rice productivity and food security of China. On the other hand, the potential gene horizontal transfer and release into en- vironment of GM rice might cause a serious issue of biological and environmental safety. Former papers have demonstrated that for- eign genes would flow to non-transgenic cultivars and wild relative species by outerossing. For example, under different experimental conditions, transferred herbicide resistance genes showed a frequency from 0.05% to 0.53% to escape, while the most probability drifting to male sterile lines was up to 4.518%. At the same time, the highest average drifting frequency from insect-resistance transgenic rice to neibouring non-transgenie rice was 0. 875%. In this article, several key aspects of the GM rice were addressed, including the hybridization of rice eultivars with their wild relatives, the transgene flow from GM rice to non-GM rice cultivars, and the flow from the wild relatives to the wild allies and their potential ecological risks. Meanwhile, a brief analysis was made on the environmental biosafety problems of GM flee. And a perspective on GM rice was given in the end of the article. The study will pro- vide the reference for security application of transgenic rice.