复合性状转基因水稻B2A68在南京地区杂草化的风险评估

The Risk Assessment of Potential Weediness of Gene Stacked Rice B2A68 in Nanjing Area

为评估复合性状转基因水稻B2A68大规模推广后演化为杂草的生态风险,在农田生态环境下比较了抗虫抗除草剂复合性状转基因水稻B2A68、抗除草剂转基因水稻Bar-68和常规稻宁粳46的生存竞争能力、繁育能力、落粒性、萌发能力、种子活力保存能力。结果表明,无论在适宜期还是非适宜期,直播和移栽条件下的B2A68与Bar-68的生存竞争能力和繁育能力均无显著差异,而与常规稻相比,B2A68也没有表现出明显的优势。B2A68与Bar-68的落粒性无显著差异,但显著优于常规稻,3种水稻的落粒性处于中等水平。田间自生苗调查结果显示,3种水稻均无自生苗出现。收获的水稻种子进行了萌发和埋藏试验,结果显示,3种水稻的萌发率无显著差异,播后7 d时的萌发率均在90%以上;在浅埋和深埋处理下,种子活力随着时间延长而下降,但2种转基因水稻种子活力显著低于常规稻。以上结果表明,复合性状转基因水稻B2A68在南京地区演化为杂草的可能性较小。

To evaluate potential ecological risk of weediness for gene stacked rice B 2A68,the survival and reproduction ability,seed shattering,seed germination rate,and seed viability of the transgenic insect -resistant and glufosinate -toler-ant rice B2A68 was studied in the field in comparison to glufosinate -tolerant rice Bar -68 and conventional rice Ningjing46（CR）.Regardless of being grown in the appropriate season and in an unfavorable season ,the survival and reproduction ability of B2A68 was no significantly different to that of Bar -68 under direct seeding or transplanting ,and B2A68 did not have increased competitive ability over CR .Seed shattering of B2A68 was similar to that of Bar-68,both of them shatter more seed than that CR but the shattering of the three rice varieties were at a same level .No volunteer plants were found in the experimental field .The three rice varieties had similar germination rates above 90% at 7 days after sowing or before transplanting .Seed viability of three rice varieties decreased with time under shallow or deep burial;seed viability of B2A68 and Bar-68 decreased faster than that of CR .It is concluded that the potential weediness of B2A68 was low in Nanjing ,China.