PROBLEM TO BE SOLVED: To provide a method for detecting plant viruses, in more detail, a method for simultaneously detecting a plurality of separated strains of apple chlorotic leaf spot virus (hereinafter referred to as ACLSV) and to obtain an oligonucleotide usable in the method.
SOLUTION: This method for detecting the ACLSV comprises using an RNA extracted from a tissue of a plant to be tested as a template, carrying out the nucleic acid amplification with a first homologous primer and a first complementary primer capable of amplifying a first partial region of a genomic RNA of the plurality of separated strains of the ACLSV, providing a first amplification product, then using the first amplification product as a template, carrying out the nucleic acid amplification using a second homologous primer and a second complementary primer capable of amplifying a second partial region contained in the first partial region of the genomic RNA of the plurality if separated strains of the ACLSV, providing a second amplification product and thereby detecting the ACLSV from the plant to be tested. The plurality separated strains of the ACLSV can simultaneously be detected. As a result, the infection of an apple tree with the ACLSV can accurately be diagnosed without selecting the time can be carried out. Thereby, an apple nursery stock uninfected with the ACLSV can be supplied.