▎ 摘　　要

NOVELTY - Polysaccharide-based bactericidal material, comprises at least one cationic modified polysaccharide and at least one photothermal conversion material, where the photothermal conversion material and the cationic modified polysaccharide are combined by physical coating, the cationic modified polysaccharide includes cationic compounds and polysaccharide macromolecules, the cationic compound is combined with the polysaccharide polymer through chemical bonding to form a cationic modified polysaccharide. USE - The material is useful in the spread and infection of pathogenic microorganisms by bacteria or fungi and in the prevention and control of seed and grain spoilage caused (claimed). ADVANTAGE - The bactericidal material can be easily processed into various forms of bactericidal materials e.g. solid powder, microspheres, emulsions and films. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing the bactericidal material, comprising (a) reacting with polysaccharide macromolecule and cationic compound as raw materials to obtain the product cationic modified polysaccharide, and preparing the polysaccharide-based bactericidal material by physical blending and coating with the photothermal conversion material; and (2) preventing and controlling agricultural and forestry diseases, comprises combining the polysaccharide-based bactericidal material with bacteria, spreading pathogenic microorganisms e.g. fungi and contact with agricultural and forestry crops that cause agricultural and forestry diseases, or, combining the polysaccharide-based bactericidal material, spreading of pathogenic microorganisms e.g. fungi and contact with food that causes spoilage, or, combining the polysaccharide-based bactericidal material with bacteria, spreading pathogenic microorganisms, e.g. fungi in contact with the environment where the infection causes the disease.