Abstract: Helminthosporium gramineum f. sp. echinochloae(HGE)is a promising biological control barnyard grass agent. To establish the genetic transformation system of HGE, the optimum conditions including mycelium incubation time, various compounding of enzymes and osmotic stabilizers for protoplast isolation and regeneration from HGE protoplasts were examined. The results indicated that protoplasts were optimally isolated when mycelia of HGE had been cultured for 6 h, and digested with 1% Drislase at 26℃ for 2 h in osmotic stabilizer of 0.7mol·L^-1 NaCl solution. The maximum regeneration ratio was obtained on the R1 regeneration medium when the mycelia of HGE were inoculated after 16 h, and digested with 0.5% Drislase at 32℃ for 4 h in 0.7mol·L^-1 NaCl solution．

Key words: Helminthosporium gramineum f. sp. echinochloae (HGE), formation of protoplast, generation of protoplast, biological control of barnyard grass