Abstract
Brown root rot disease caused by a fungi pathogen, Phellinus noxius, is one of the most severe diseases of forest trees. This disease is not easy to be diagnosed by its incited symptoms especially in the early stage of infection.In 2009,we have the rapid detection technique to accurate detection for P. noxius using the PCR assays to elevate the efficiency of diagnosis. In this study, we further establish a standard operating procedure with the PCR assay using root tissues and soil samples. We made the comparative effects in PCR assays with different DNA extraction methods from either diseased root tissues or soil samples. Three experimental treatments were used in this study for the comparative efficiency among them including (1) DNA extraction from root tissue and soil samples using commercialized DNA extraction kit; (2) DNA extraction from root tissues and soil samples using traditional organic extraction method; (3) DNA extraction from the mycelium grown on the culture medium inoculated by diseased root tissues and soil samples using traditional organic extraction method. The data showed that all DNA extraction methods could obtain good results for the detection of P. noxius, but the commercialized DNA extraction kit seemed to be somewhat more sensitive than the other methods. Besides, the results indicated that the populations of P. noxius in the diseased root tissues are more than those in the soil sample. Therefore, the diseased root tissues are better for the examination of P. noxius than soil samples. For the tests of soil samples, double PCR assays were better to obtain sensitive results of detection. This study aids the establishment of the standard operating procedure (SOP) for detection of P. noxius including the entire PCR procedure and sampling either from root tissues or soil.