The invention provides
lentinan as well as a preparation method and application thereof, and belongs to the technical field of
plant protection. According to the preparation method, a ZTC 1 + 1 II type
clarifying agent is used, and step-by-step
flocculation purification is carried out at 50 DEG C according to a sequence of firstly adding a component B and then adding a component A and specific stirring parameters. According to the process, impurities such as
protein are efficiently removed, the active conformation of
lentinan is well reserved, and the antiviral activity of the product is remarkably improved. Meanwhile, the invention finds that when the
lentinan obtained by the invention is mixed with oligosaccharin.chain
protein in a
mass ratio of 7: 3 or 9: 1, the lentinan shows a remarkable specific synergistic effect. The invention solves the problems of poor product stability and large activity loss in the prior art, and is especially suitable for prevention and treatment of
plant virus diseases such as
tomato mosaic virus diseases.