Abstract: In order to study the induced insect resistance of Rosa rugosa ‘plena’, the influence on the activity changes of defensive enzymes in leaves of R.rugosa ‘plena’ induced by mechanical wounding was studied. The results showed that the activities of phenylalanine ammonia lyase(PAL), polyphenol oxidase(PPO) and peroxidase(POD), were all increased by mechanical wounding, the activities of PPO, POD were first increased, and then decreased, the higher PAL activities remained longer than the other enzymes. T3(mechanical wounding, 3 holes per leaf) treatment was the most appropriate damage degree, the activities of PAL, PPO and POD reached their maximal levels on the 7th, 3rd and 5th days induced by T3 treatment respectively. Hence, it could be concluded that appropriate wounding could induce higher defensive enzyme activities to improve the defensive capability of R.rugosa ‘plena’.

Key words: mechanical wounding, Rosa rugosa &lsquo, plena&rsquo, phenylalanine ammonia lyase, olyphenol oxidase, peroxidase, induction