不同还田方式对Bt玉米秸秆中Bt蛋白田间降解的影响  

Effects of straw return pattern on the degradation of Bt protein released from Bt corns in field

作　　者：王建武[1] 范慧芝[1] 冯远娇[1] 

机构地区：[1]华南农业大学热带亚热带生态研究所,广州510642

出　　处：《生态学杂志》2009年第7期1324-1329,共6页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(30470335;30770402);广东省自然科学基金项目(E039254;06025813);广东省科技计划资助项目(2006B50104002;2007A020300009-1)

摘　　要：采用网袋法在田间研究了Bt(Bacillus thuringiensis)玉米(Zea may)1246×1482和H9235Bt/RR秸秆中Bt蛋白的降解动态,并应用移动对数模型进行拟合及估算DT50和DT90,探讨不同还田方式对降解的影响。结果表明:1246×1482和H9235Bt/RR秸秆中Bt蛋白在埋入土壤和地表覆盖2种还田方式下均能在7d内降解90%以上,但还田180d时仍能检测到占初始含量0.004%～0.069%的Bt蛋白;不同还田方式并没有显著影响到1246×1482秸秆中Bt蛋白的降解过程,其埋入土壤和地表覆盖处理的DT50分别为0.90d和0.79d,DT90则分别为3.45d和5.03d;但不同还田方式影响了另一Bt玉米H9235Bt/RR秸秆中Bt蛋白的降解过程,在秸秆还田前期,埋入土壤处理下Bt蛋白的降解比地表覆盖处理慢,其埋入土壤和地表覆盖处理下Bt蛋白降解的DT50分别为6.80d和0.54d,DT90则分别为21.76d和7.12d。由此可见,2个Bt玉米品种秸秆中Bt蛋白在2种还田方式下均能快速降解,不同还田方式只影响到H9235Bt/RR秸秆中Bt蛋白的田间降解,使得地表覆盖处理下Bt蛋白的降解比埋入土壤处理快。By using litterbag method, this paper studied the degradation of Bt protein released from CrylAb Bt corns 1246×1482 and H9235Bt/RR under two straw return patterns, i. e. , buried in soil and covered on soil surface, and the DT50 and DT90 were fitted and estimated by shiftlog model. Under the two straw return patterns, more than 90% of the Bt protein from the two Bt corns were degraded within one week, only 0. 004%-0. 069% of their initial Bt protein being detected after the Bt corn straws returned to field for 180 days. Less difference was observed in the degradation of Bt protein from Bt corn 1246×1482 under different straw return patterns, with the DT50 and DT90 being 0. 90 d and 3.45 d when the straws were buried in soil, and 0. 79 d and 5.03 d when covered on soil surface, respectively. However, the degradation of Bt protein from H9235Bt/RR was manifestly affected by the straw return pattern. At the early stage of straw return, the degradation rate of Bt protein from H9235Bt/RR was lower when the straws were buried in soil than covered on soil surface, with DT50 and DT90 being 6. 80 d and 21.76 d, and 0. 54 d and 7. 12 d, respectively. It was suggested that the Bt protein both from Bt corn 1246×1482 and from H9235Bt/RR could be degraded rapidly in field, and straw return pattern only affected the degradation of Bt protein from H9235Bt/RR, with a much higher degradation rate when the straws were covered on soil surface.

关 键 词：BT玉米 BT蛋白 秸秆还田 降解 拟合模型 

分 类 号：S513[农业科学—作物学] S154