烟区轮作与连作土壤细菌群落多样性比较

Diversity comparison of soil bacteria communities in rotation and continuous flue-cured tobacco cropping

采用从土壤中直接提取土壤细菌总DNA,并用细菌16SrDNA特异性引物进行PCR扩增和变性梯度凝胶电泳（DGGE）的方法,对比研究了贵州福泉烟区轮作和连作对土壤细菌群落多样性的影响,每个处理样品3次重复在DGGE图谱中相似性较高,基本聚在一起,从整体证明了试验操作方法较为精确。由DGGE图谱可知,轮作土壤微生物条带数量15-31条不等,平均为23条。连作土壤微生物条带数量从7-25条不等,平均为18条。分别从每条泳道的条带数和光密度值两方面,对细菌群落多样性指标进行了比较。结果表明,轮作处理细菌群落丰富度指数均大于连作处理,轮作Shannon-wiener和辛普森指数（1/D）均大于连作,表明轮作微生物多样性较连作高,轮作方式可以提高植烟土壤细菌群落的多样性。

Bacterial diversities in soils of rotation and continuous flue-cured tobacco cropping were measured by using 16SrDNA PCR-DGGE profiling.Crude bacterial DNA was extracted from soil.Amplification of 16S rDNA by PCR was made by a pair of specific bacterial primers,and then cDNA products were separated by denaturing gradient gel electrophoresis.The bands on gel in-dicated the bacterial diversity in the soils of rotation and continuous flue-cured tobacco cropping.The high similarities in three repli-cates suggested the reliability of method in the experiments.Based on the DGGE profile,15 to 31 bands（averagely 23）were ob-served in the soils of rotation cropping,while the corresponding value is from 7 to 25,avergely 18 in continuous cropping.According to the electrophoretic bands and optical density value,it was suggested that bacterial community of richness was higher in rotation than continuous tobacco cropping.The Shannon-wiener index and Simpson index（1/D）were also higher in rotation than continuous cropping.Taken together,our resutls indicated rotation tobacco cropping could improve the bacterial diversity of soils.