Abstract: In greenhouse, the F1 and F2 hybrids derived from glufosinateresistant transgenic rice (Y0003 and 991) and Malaysian weedy rice or Anhui weedy rice were backcrossed with corresponding weedy rice to obtain backcross generations. And the seed setting rates of the backcross were counted. The proportions of plants carrying the glufosinateresistance gene in F1 or F2 hybrids and the backcross generation were calculated. In order to comprehensively assess the risk of gene flow from glufosinateresistant rice to weedy rice, the fitness of hybrid and backcross generations were observed. The results showed that the hybrid generations were able to backcross with corresponding weedy rice with seed setting rates from 15% to 60%. The seeds from reciprocal hybrid F1 generation showed favorable glufosinateresistance, but F2 and backcross generations showed a normal 3∶1 and 1∶1 Mendelian segregation with glufosinate selection. The fitness of hybrid and backcross generations didn′t differ obviously from that of their corresponding weedy rice. Most hybrid generations displayed similar fitness with backcross generations, but some hybrid generations were lower than backcross generations in fitness. All above results indicate that hybrids and backcross generations of two weedy rice carrying glufosinateresistance genes of Y0003 and 991 could survive under benign conditions without herbicide selection.

Key words: herbicideresistant transgenic rice, weedy rice, progeny, environmental biosafety, fitness

摘要： 在温室条件下，将抗除草剂转基因水稻Y0003和991与马来西亚杂草稻和国内安徽塘稻人工授粉获得的携带抗性基因的F1、F2与相应杂草稻回交，统计回交结实率和携带抗性基因的比例，并对携带抗性基因的杂交/回交代的适合度进行了测定，综合判断抗性基因漂移的风险。研究表明，在人工授粉的条件下，携带抗性基因的杂交代都能与相应的杂草稻回交并结实，结实率为15%~60%。F1的种子绝大多数都对草丁膦表现出了良好的抗性，F2和回交代分别表现为3∶1和1∶1的抗性分离比例，符合孟德尔遗传规律。适合度研究表明，杂交代、回交代与相应的杂草稻相比没有明显差异，大多数的杂交种的适合度和回交代相差不大，个别杂交代的适合度没有回交代高。以上研究结果表明在无除草剂选择压下，携带转基因水稻Y0003和991的抗性基因的2种杂草稻的杂交和回交后代有在适宜环境条件下生存定植的可能性。

关键词: 抗除草剂转基因水稻, 杂草稻, 后代, 环境安全性, 适合度