dsRNA in Cryphonectria parasitica could be transmitted to progeny through conidia with varying efficiency in culture.Both light and prolonging cultural time could reduce the transmission efficiency,but the effect of light was more efficient.No dsRNA segments were found to be loss after 30 generations subculture,indicating that dsRNA could transmitted stably through subculture.Vegetative incompatibility was a barrier for the transfer of dsRNA from one isolate to another,and hypovirulence conversion reduced as the number of different VC genes between donor and recipient isolates increased.