【作者】 董斌；

【导师】 虞云龙；

【作者基本信息】 浙江大学 ， 农药学， 2011， 硕士

【摘要】 随着转基因作物的发展,其种植及残留物对土壤环境质量的影响越来越受关注与重视。本文以两株转Bt水稻(华池B6和TT51)为供试材料,并以其亲本嘉早935、明恢63和远缘亲本中九B、9311为对照,研究了其连续两年种植及秸秆还田期间对土壤酶活性(中性磷酸酶、脲酶、蔗糖酶和过氧化氢酶)、厌氧呼吸作用、土壤微生物功能和结构多样性的影响。主要研究结果如下1.通过高锰酸钾滴定法测定土壤过氧化氢酶活性,比色法测定土壤中性磷酸酶、脲酶和蔗糖酶活性,结果显示在两年种植和秸秆还田期间转Bt水稻、亲本和远缘亲本处理对土壤过氧化氢酶活性无显著差异,但Bt水稻对土壤中性磷酸酶、脲酶和蔗糖酶活性有短暂的显著影响,亲本和远缘亲本之间也存在短暂的显著差异。2.采用底物诱导法测定土壤厌氧呼吸CO2的释放量,结果表明Bt水稻种植及秸秆还田均对土壤厌氧呼吸作用无显著持续的负面影响。培养24h后土壤无氧呼吸产生的CO2无显著差异,而厌氧培养7h土壤产生的CO2存在短暂显著差异,这些差异也存在于亲本与远缘亲本间。3.应用Biolog ECO微平板来测定土壤微生物碳源利用多样性。结果显示土壤微生物群落AWCD值、Shannon指数、McIntosh指数在Bt水稻、亲本和远缘亲本处理间均不存在显著差异,而Simpson指数和碳源利用方式上存在短暂的显著差异。4.应用16S rDNA PCR-TGGE法分析土壤微生物群落结构多样性。结果显示Bt水稻、亲本和远缘亲本处理之间土壤微生物种群结构相似,未发现不同的TGGE条带,但某些条带亮度上存在差异,说明某些细菌的生物量存在一定差异,通过对这些特异性条带克隆测序分析后发现大部分属于proteobacteria类细菌,少量属于Actinobacteria、Clostridia、Anaerolineae类细菌。更多还原

【Abstract】 With the development of transgenic crops, there is an increasing concern about the possible adverse effects of their vegetation and residues on soil environmental quality. To evaluate the effect of vegetation of transgenic Bt rice followed by return of rice straw on microbe-mediated functions in soil under field conditions, two Bt transgenic rice lines, Huachi B6 (Bt-HC) and TT51 (Bt-T), were adopted to assess the possible effect on soil enzyme (neutral phosphatase, urease, catalase, and invertase) activities, soil anaerobic respiration activity, and soil microbial community structure and functional diversity. Non-transgenic parental lines [Jiazao 935(P-JZ) and Minghui 63 (P-MH)] and distant parental rice varieties [Zhongjiu B (DP-ZJ) and 9311 (DP-9311)] were used as the controls. The results were summarized as follows:1. The activity of catalase was assayed by the KMnO4 titrimetric method, and activities of neutral phosphatase, urease and invertase were measured by colorimetry. The results indicated that the vegetation and straw addition of the two transgenic rice lines (Huachi B6 and TT51) have few adverse effect on soil enzymes, compared with their parent and distant parent, although some transient or even significant differences were observed. And there were also some significant differences between parental and distant parental rice.2. The evolution of CO2 from soil anaerobic respiration was analyzed by substrate induced method. The results demonstrated that cultivation of Bt-transgenic rice and addition of their straw have no persistent and adverse effect on soil anaerobic respiration activity.3. The functional diversity of soil microbial communities was assessed using Biolog ECO microplates. There were no significant difference between Bt, parent and distant parent in the AWCD, richness, and evenness of soil microorganisms. The dominant population of soil microbial communities seemed to be more sensitive and was altered temporarily by vegetation and straw amendment of Bt rice. This alteration is, however, smaller than that caused by vegetation and straw amendment of non-transgenic distant parental rice. 4. Soil microbial community structure was analyzed using 16S rDNA-based PCR-TGGE. There were no different bands between Bt and non-Bt in TGGE gel, but some brightness differences were detected. By recovery, cloning and sequence analysis, these bands with brightness differences may probably belong to Proteobacteria, Actinobacteria, Clostridia, and Anaerolineae.更多还原