Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Characterization of a mycovirus associated with the brown discoloration of edible mushroom, Flammulina velutipes | Magae and Sunagawa Virology Journal 2010 7 342 http content 7 1 342 VIROLOGY JOURNAL RESEARCH Open Access Characterization of a mycovirus associated with the brown discoloration of edible mushroom Flammulina velutipes Yumi Magae Masahide Sunagawa Abstract Background A mycovirus previously identified in brown discolored fruiting bodies of the cultivated mushroom Flammulina velutipes was characterized. We tentatively named the virus the F. velutipes browning virus FvBV . Results Purified FvBV particles contained two dsRNA genomes dsRNA1 and 2 . The complete sequence of dsRNA1 was 1 915 bp long containing a single open reading frame ORF that encoded 580 amino acids of a putative 66-kDa RNA-dependent RNA polymerase RdRp . dsRNA2 was 1 730 bp long containing a single ORF encoding 541 amino acids of a putative 60-kDa coat protein CP1 . Phylogenetic analysis of the RdRp sequences revealed FvBV to be a Partitivirus most closely related to Chondrostereum purpureum cryptic virus. An RT-PCR assay was developed for the amplification of a 495-bp cDNA fragment from dsRNA encoding the CP1. When wild F. velutipes isolated from various parts of Japan were examined by RT-PCR assay three isolates from the central region of Japan contained FvBV. One wild strain infected with FvBV was isolated in Nagano prefecture where brown discoloration of white cultivated strains has occurred. Fruiting bodies produced by virus-harboring and virus-free F. velutipes were compared. Conclusions Cap color of the fruiting bodies of F. velutipes that contained Partitivirus FvBV was darker than FvBV-free fruiting bodies. The use of RT-PCR enabled association of FvBV and dark brown color of the fruiting body produced by F. velutipes strains. Background At the time mycoviruses were discovered in the white button mushroom Agaricus bisporus in 1962 1 Lenti-nula edodes was the only artificially cultivated mushroom in Japan. Since then the number of cultivated mushroom species has greatly .
