Species composition of Pratylenchus (Nematoda: Tylenchida) in crop fields of central Japan, along with an observation of the geographic border lying between Pratylenchus coffeae and its closely allied species

摘要

A survey of the Pratylenchus species was conducted in crop fields of Central Japan to show the species composition, and a geographic border of distribution lying between Pratylenchus coffeae and its closely allied species (Pratylenchus sp.). Pratylenchus species were found in 47 soil samples from the fields of soybean, red bean, corn, taro, potato, barley, and upland rice. Identification of the species was solely conducted on the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) bases in a partial region of ribosomal DNA. Five species of Pratylenchus were detected in this region. Pratylenchus penetrans was found most frequently from the crop fields examined (species composition rate: 72.3 percent), followed by Pratylenchus sp. (14.9 percent), P. neglectus (12.8 percent), P. coffeae (8.5 percent), and P. vulnus (4.3 percent). Species composition of Pratylenchus within the kind of crops is compared. Pratylenchus coffeae was detected from four sites in Tochigi, Saitama and Chiba Prefectures, and Pratylenchus sp. was found from seven sites in Tochigi and Saitama Prefectures: it is presumed that the geographic border of the two species lies between Tochigi and Saitama Prefectures.