Development of a quantification method with real-time PCR for three Pratylenchus species causing damage to chrysanthemum in Japan

ThreePratylenchusspecies,P. penetrans,P. pseudocoffeaeandP. kumamotoensis, are major threats to chrysanthemum production in Japan. To develop a quantification method for these threePratylenchusspecies in soil using real-time PCR, we designed two new specific primer sets forP. pseudocoffeaeandP. kumamotoensisand applied the primer set NEG, developed previously, forP. penetrans. Relationships between the threshold cycle (Ct:y) values and number of nematodes inoculated (log2(no. (20 g soil)−1):x) were forP. penetrans,P. pseudocoffeaeandP. kumamotoensis. The quantification of thesePratylenchusspp. was conducted using 16 soil samples.Pratylenchus penetransandP. kumamotoensiswere detected from seven and one soil samples, respectively, while noP. pseudocoffeaewas detected. These results demonstrated that the presently designed primers are useful to quantify the densities of threePratylenchusspp. in chrysanthemum fields in Japan.