种植年限对牡丹根际土壤微生物群落结构的影响

EFFECTS OF PLANTING YEARS ON MICROBIAL COMMUNITIES' STRUCTURE IN PEONY RHIZOSPHERE SOIL

为了探究牡丹连作对土壤微生物种群结构的影响,从菏泽牡丹园采集种植年限分别为3、5、8、12、20年的牡丹根际土壤样品,采用末端限制性片段长度多态性(T-RFLP)技术与变性梯度凝胶电泳(DGGE)方法研究了样品中细菌和真菌的种群结构变化。结果表明,牡丹根际土壤细菌多样性变化不显著,而真菌多样性水平随种植年限的增加而降低,菌群结构趋于简单,种类大量减少。通过戴斯系数法对牡丹根际土壤的细菌与真菌DGGE图谱分析表明,各样品间细菌种群结构相似度均在76.9%以上,而牡丹根际土壤样品真菌种群结构相似度最低仅为58.3%,说明随着种植年限增加牡丹根际细菌种群结构未发生显著变化,而根际真菌种群结构变化显著。牡丹连作后真菌种群结构的变化可能是引发牡丹连作障碍的主要原因。

In order to exploring the effect of peony continuous cropping on the microbial community structure in soil,Samples were collected from peony having been planted for 3, 5, 8, 12 and 20 years in Peony Garden of Heze. T - RFLP and DGGE technique was adopted to study the dynamic changes of bacteria and fungi communi- ty structure in the rhizosphere soil. The results showed that with increasing year of cropping, the bacteria com- munity was not signicantly changed. However the fungi diversity level was significantly reduced, and its commu- nity structure tend to be simple. Dice coefficient analysis of DGGE figures showed that bacterial community structure similarity of each peony rhizospheric soil sample were over 76.9%, but the lowest fungi community structure similarity of each peony rhizospheric soil sample were only 58.3%. The results from Dice coefficient analysis are similar to that from T - RFLP. The changes of fungi community diversity under continuous cropping of peony might be one of the main reasons causing the obstacles of continuous cropping of peony.