转基因棉花连续种植对土壤AM真菌群落结构的影响

为评价转基因棉花种植对土壤中AM真菌群落结构的影响，以转基因棉花013011（抗旱）、SGK321（抗虫）和非转基因棉花TH2（抗旱受体）、石远321（抗虫受体）为材料，研究不同生育期转基因棉花土壤中AM真菌的群落结构。采用PCR-DGGE技术对土壤中AM真菌的群落结构进行分析。结果发现：转基因棉花与非转基因棉花在花铃期和吐絮期土壤中AM真菌群落的最小相似度均大于0.6，这说明了转基因棉花的种植在花铃期和吐絮期均未对土壤中AM真菌的群落结构产生影响。另外转基因棉花和非转基因棉花的种植在花铃期和吐絮期均未对土壤AM真菌的丰富度（S）造成影响；土壤AM真菌香农-维纳指数（H）仅在吐絮期石远321显著低于SGK321，其余品种和时期均未出现显著性差异；土壤AM真菌的均匀度（E_H）仅在吐絮期发现TH2显著高于013011，其余品种和时期均未出现显著性差异。DGGE指纹图谱结果表明转基因棉花与非转基因棉花同一生长时期多为共有条带，且同一时期土壤AM真菌群落结构相似性较高，AM真菌的群落结构无明显变化。两个不同生育期优势属均为Glomus（球囊霉属）。研究表明：土壤AM真菌的群落结构变化只随着棉花生育期的不同会有短暂的变化，与是否为转基因棉花无显著性相关。

Effects of continuous planting of transgenic cotton on the community structure of AM fungi in soil

To detect the effects of cultivating transgenic crops on the community composition of soil arbuscular mycorrhizal (AM)fungi, we employed two transgenic cotton varieties, 013011 (drought-resistant)and SGK321 (insect-resistant), and their parental varieties TH2 (drought-resistant receptor)and Shiyuan321 (insect-resistant receptor). The Polymerase chain reaction-Denaturing gradient gel electrophoresis (PCR-DGGE)technology was used to analyze the community structure of the AM fungi in the soil. The results showed that the minimum similarity of the AM fungi in the soil with planted transgenic cotton and non-transgenic cotton was 0.6, indicating that the transgenic cotton planting had no significant effect on the community structure of the AM fungi in the soil during the blooming and the wadding stages. No significant difference in the richness (S)of the AM fungi was found between the soils planted with the transgenic and non-transgenic cotton during the blooming and wadding stages. The Shannon-Wiener index (H)of the AM fungi in the soil planted with Shiyuan 321 was significantly lower than that planted with SGK321 only at the wadding stage, However, no significant difference found among the other growing periods and other cotton types. The evenness (E_H)of the AM fungi in the soil planted with TH2 was significantly higher than that planted with 013011 only at the wadding stage, but no significant difference was observed among the other cotton types and growing periods. The DGGE fingerprinting of the AM fungi in soil planted with the transgenic cotton was very similar to that planted with the non-transgenic cotton at the same growing stage, indicating that the impacts of planting the transgenic cotton on the community structure of the AM fungi in soil was small. The predominant genera were Glomus during both the flowering and boll-setting periods. The community structure of the AM fungi in the soil only change temporarily with the growing periods, but is hardly affected by the planting of the transgenic cotton.