中文摘要：

通过传统培养和PCR-DGGE技术,分析了新疆南疆不同连作年限的棉田土壤微生物的变化情况,结果表明：随着连作年限的增加,土壤中细菌、真菌的数量、比例、多样性指数的变化表现为先增加后下降,至连作15年时达到较低值,之后随着连作年限的继续增加又表现为回升的趋势。细菌的种类数、优势种在不同连作年限的样品中的变化不明显,多样性指数变化幅度较小,群落结构变化不大;真菌的种类数、优势种在不同连作年限的土样中的变化较大,群落结构变化较大,随着连作时间的增加,优势种的种类趋于单一化,真菌的群落结构受到连作年限的影响更明显。

英文摘要：

Through the method of traditional culture and PCR-DGGE, variety of soil microbial structure in continuous cropping cotton fields in south Xinjiang was analyzed. The results showed with the increase of continuous cropping years, the number of bacteria and fungi, ratio of total bacteria and fungi and Shannon-Weiner index increased at first, than decreased, and after continuous cropping 15 years increased again, it was a lower point in the sample of continuous cropping cotton 15 years. Bacterial diversity and structure changed slightly, while the quantity and species of dominant bacteria were not much different in the fields with different continuous cropping years. Compared with bacteria, fungi structure was more sensitive to continuous cropping years, dominant fungi population presented a single tendency and lower species diversity.