Abstract: 【Objective】Potato virus Y (PVY) is one of the most destructive pathogens constraining sustainable development of potato industry. The objective of this study is to develop a fast, easy-to use and accurate approach to timely detect PVY strains and apply the approach to investigate the occurrence, distribution and composition of PVY strains in Fujian province. 【Method】ELISA method was used to confirm the presence of virus in the PVY-alike leaf samples randomly collected from Changle and Fuqing cities in Fujian province. Three pairs of degenerate primers designed from the conserved regions of P1, VPg and CP genes in the reference PVY sequences downloaded from GenBank were used to amplify the positive samples by ELISA test. Nucleotide identity and recombination events between isolates from Fujian and strains downloaded from GenBank were evaluated and phylogenetic tree was reconstructed using concatenated sequences of the three genes. 【Result】ELISA confirmed that 13 out of the 17 samples collected from the two potato producing areas were infected with PVY. RT-PCR amplifications of all 13 ELISA-positive samples generated the expected sizes of fragments corresponding to the three genes. Individual gene analyses showed that P1, VPg and CP sequences in Fujian isolates shared 72%-99%, 85%-99% and 88%-99% nucleotide identity with the reference strains, respectively. Concatenated sequence analysis showed that FQ01 and FQ08 isolates shared the highest sequence identity with PVY^N-Wi and PVY^E, respectively; CL01, CL02, CL05 and CL13 isolates shared the highest sequence identity with PVYN^TN-NW (SYR-I), whereas CL03, CL04, FQ02, FQ06, FQ09, FQ11 and CL12 shared the highest sequence identity with PVY^NTN-NW (SYR-II). Recombination signals were identified in P1 and VPg genes but not in CP of PVY, which isolated from Changle and Fuqing cities in Fujian province. Further analyses showed that in Changle City, P1 gene was composed of two lineages, with 60% being N lineage and 40% being N×O lineage. All VPg genes were N×O lineage and all CP genes were classified as O lineage. Similarly in Fuqing city, P1 gene was consisted of two lineages, with 25% being N lineage and 75% being N×O lineage; 87.5% VPg genes were N×O lineage and 12.5% was O lineage; and all except one (which was classified as N lineage) CP genes were O lineage. Phylogenetic tree revealed that isolates CL01, CL02, CL05 and CL13 were grouped with PVY^NTN-NW (SYR-I) and isolates CL03, CL04, FQ02, FQ06, FQ09, FQ11 and CL12 were clustered with the PVY^NTN-NW (SYR-II), whereas isolate FQ01 was grouped with PV^YN-Wi and isolate FQ08 was clustered with the PVY^E, respectively. These results indicated that evolutionarily, CL01, CL02, CL05 and CL13 are closer to PVY^NTN-NW (SYR-I); CL03, CL04, FQ02, FQ06, FQ09, FQ11 and CL12 are closer to PVY^NTN-NW (SYR-II), FQ01 is closer to PVY^N-Wi and FQ08 is closer to PVY^E, respectively. 【Conclusion】PVY occurs frequently in Changle and Fuqing cities in Fujian province and recombinant strains, particularly PVY^NTN-NW are dominant in the PVY isolates from the province.

Key words: Potato virus Y (PVY), ELISA, concatenated sequence, phylogeny, recombinant strain