Abstract: We examined the effects of continuous planting on fungi diversity of Fusarium in the rhizosphere soil of Chinese fir plantation. We analyzed the composition and content of Fusariumin soils of the first (FCP), second (SCP), and third (TCP) generation of Chinese fir plantations using DGGE technology, and measured the absolute content of Fusarium oxysporum in rhizosphere soil using qRT-PCR technique. DGGE results showed that the composition and content of Fusarium in the rhizosphere soil changed significantly after multiple generations of planting, with the content of F. oxysporum being increased significantly with increasing generation. Through principal component analysis, Fusarium community characteristics of FCP, SCP and TCP rhizosphere soil were well distinguished. The results of cluster analysis showed that the structural composition and percentage of Fusarium in the TCP soil were significantly different from those of FCP and SCP. The results of diversity analysis showed that the diversity and richness ofFusariumdecreased following a sequence of FCP<SCP<TCP. The results of qRT-PCR analysis showed that the absolute content of F. oxysporum in the rhizosphere soil of FCP, SCP and TCP increased continuously with increasing planting generation, which further verified the DGGE results. Ourresults suggest that the continuous planting obstacles of Chinese fir are closely related to the micro-ecological imbalance in rhizosphere soil, with the increase ofF. oxysporum content being one of the important factors.

Key words: Chinese fir, rhizosphere soil microbe, Fusarium community structure, DGGE, qRT-PCR.