转基因水稻与野生稻(Oryza nivara Sharma et Shastry)杂交后代种子萌发率

Seed Germination Test for Hybrids between Transgenic Cultivated Rice(Oryza sativa) and Annual Common Wild Rice(Oryza.nivara)

种子休眠性是野生植物重要的适应性状,通过种子萌发实验可以分析种子休眠性强弱.通过人工杂交获得转抗虫基因栽培稻与一年生普通野生稻三种组合的杂种,对杂种的F3代和F4代种子采用直接萌发、打破休眠后萌发、埋土15 d和30 d 4种不同处理来检测种子活力和萌发率.结果显示转基因杂种后代种子表现出较强的休眠性,转基因对种子活力和休眠性没有明显的影响,种子休眠性有随种子世代的增加而逐渐减弱的趋势,提示水稻转基因逃逸后有在野生稻群体中宿存和扩散的可能性,但这种可能性可能会随世代增加而下降.这为进一步研究水稻转基因逃逸风险提供了参考.

Seed dormancy, which is an important adaptive characteristic for wild plant species, can be determined by germination tests. The presence of seed dormancy is generally considered a primitive trait of common wild rice（ Oryza nivara and O. rufipogon ） in comparison with cultivated rice （ O. sativa）. Seed dormancy of hybrids between transgenic rice and wild rice can be therefore of importance for assessing the possibility of transgene persistence in wild populations after it escaped through crop-to-wild gene flow. Seed germinations were compared between the F3 and F4 generation progenies of hybrid between an insect-resistant transgenic rice line （ CpTI rice） and annual common wild rice （ O. nivara） under four different treatments. The results showed that the transgenic hybrid seeds presented relatively strong dormancy, the seed viability and dormancy were not significantly associated with transgene, and the degree of seed dormancy in progenies would decline from one generation to the next. This result suggests the possibilities of transgene persistence and spread in the wild populations after transgene escape, although the possibilities might decline from generation to generation.