关键词: 烤烟, 连作, 根际土壤, 细菌群落, PCR-DGGE

Abstract: The bacterial colonies of soil samples were analyzed by PCR-DGGE technique in order to provide theoretical basis for controlling obstacles of tobacco continuous cropping. The results showed that soil bacterial community was rich in flue-cured tobacco mid-late growing period. There were differences in the structure of bacterial community in field soil by different continuous tobacco cropping, most of the bacterial types were common, and there were few unique bacterial types. The change of bacterial abundance in continuous cropping soil was very stable, and the continuous cropping increased the abundance of soil bacteria, and showed a tendency of firstly increasing and then decreasing. The dominant populations of rotation bacteria were stable in the field period, while the bacterial flora in continuous cropping soil had greater changes. The activities of bacteria in warm-curvae, acid bacillus door and corynebacteriaceae had strong impact on soil nutritional metabolism, the pathogens were increased, which was unfavorable for the growth and development of flue-cured tobacco. Different continuous cropping years had greater impacts on the soil bacterial population structure in flue-cured tobacco. The changes in bacterial population structure of flue-cured tobacco after continuous cropping could be one of the main reasons causing obstacles in flue-cured tobacco continuous cropping.

Key words: flue-cured tobacco, continuous cropping, rhizosphere soil, bacterial communities, PCR-DGGE