Abstract: To clarify the distribution characteristics of Rhizoctonia Solani and Sclerotium Rolfsii, which are seriously harmful to landscape plants in the urban green space in Shanghai, we quantitatively measured the abundance of ITS gene of two pathogens in the soil by realtime fluorescence quantitative PCR. Soil physical and chemical properties were simutaneously analyzed. The results showed that soil pH of green space is slightly alkaline, with high soil water content. The coefficient of variation of soil physical and chemical indices was high. The detection rates of R. solani and S. rolfsii in the soils were 99.7% and 11.6%. The average abundance of ITS gene was 9.09×10⁵ and 2.42×10⁵ copies·g^-1, respectively. There was significant difference in ITS gene abundance of R. solani between the green space soil of park and road (P<0.05), and no difference between that of downtown and suburb sites (P>0.05), indicating that green space types affect ITS gene abundance of R. solani. There was no significant difference in ITS gene abundance of S. rolfsii between the green space soil of park and road, and between that of downtown and suburban sites (P>0.05). ITS gene abundance of S. rolfsii was significantly negatively correlated with soil total chromium, total nickel, and total arsenic contents. These results contribute to better understanding of the prevention and control of R. solani and S. rolfsii in the soil of urban green space in Shanghai.

Key words: urban green space, Rhizoctonia solani, Sclerotium rolfsii, distribution characteristics, influencing factor.