Transmission of Oyster Mushroom Spherical Virus to Progeny via Basidiospores and Horizontally to a New Host .

Mycoviruses are usually transmitted horizontally via hyphal anastomosis and vertically through sporulation in natural settings. Oyster mushroom spherical virus (OMSV) is a mycovirus that infects , with horizontal transmission via hyphal anastomosis. However, whether OMSV can be vertically transmitted is unclear. This study aimed to investigate the transmission characteristics of OMSV to progeny via basidiospores and horizontally to a new host. A total of 37 single-basidiospore offspring were obtained from OMSV-infected and for Western blot detection of OMSV. The OMSV-carrying rate among monokaryotic isolates was 19% in and 44% in . Then, OMSV-free and OMSV-infected monokaryotic isolates were selected for hybridization with harvested dikaryotic progeny strains. Western blot analyses of the offspring revealed that the OMSV transmission efficiency was 50% in and 75% in , indicating vertical transmission via sexual basidiospores. Furthermore, we observed the horizontal transfer of OMSV from to . OMSV infection in resulted in significant inhibition of mycelial growth and yield loss. This study was novel in reporting the vertical transmission of OMSV through basidiospores, and its infection and pathogenicity in a new host .