Purification of the Toxic Protein from Arthrinium phaeospermum and Its Pathogenicity Establishment of a screening system for Tn5 insertion mutants of Bacillus pumilus DX01 with different anti-phytopathogenic activities Studies on the Characteristics of Crude Toxin Produced by Fusarium oxysporum f. sp. cubense Race 4 Studies on the Characteristics of Crude Toxin Produced by Fusarium oxysporum f. sp. cubense Race 4