Protoplastpreparation conditions of Stemphylium lycopersici was optimizedusing strain CS 12 fromhypha age,enzyme species and concentration,enzyme combination,enzymolysis temperature and time,isotonic solutions,and the optimal regeneration medium.Theprotoplasm preparation and regeneration of S.lycopersici was successfully established by using mycelium cultured 36 h,0.7 mol·L-1 NaCl solution as the osmotic stabilizer,10 mg·mL-1 Kitalase as enzymatic hydrolysate at 28℃for 3.5 h,and the regeneration efficiency was the highest on the YEPS regener...