Abstract: The callus of Paeonia ostii cotyledon was induced by tissue culturing of medicinal herbs.The content of paeonol in callus under different processing conditions,such as water bath time,ultrasonic time and ultrasonic power,was determined with single factor experiment and orthogonal experiment.Then,the optimal handling method was used to compare the content of paeonol in different organs and callus,and different effects on its content by growing on basic culture medium and different ratio of hormone.The results showed that the optimal processing conditions were water bath 2 h,ultrasonic treatment 30 min with ultrasonic power 100 W.The decreasing order of importance of the three processing conditions affecting content of paeonol was ultrasonic time,water bath time and ultrasonic power,successively.The above process can be used as a method of processing sample before detecting the content of paeonol in callus.The content of paeonol in different parts of P.ostii was quite different,and the decreasing order of content was Cortex Moutan,leaf,seed,pod and cotyledon callus,successively.The culture conditions of 6-BA 0.5 mg/L+2,4-D 4.0 mg/L and basic culture medium B₅ can improve the content of paeonol to varying degrees.

Key words: Paeonia ostii, medicinal herbs tissue culture, orthogonal experiment, paeonol