Jia Li

Jilin Agricultural University College of Horticulture,Changchun,Jilin 130118

sa;b. cinerea;induced resistance;spore germination;mycelial;pa

[Objective] The paper was to explore the induced resistance of tomato against gray mold (Botrytis cinerea) by salicylic acid. [Method] SA was used as an inducer to treat tomato seedlings, the effects of SA on mycelial diameter and spore germination of B. cinerea were studied, and the changes of 4 defense enzyme activities containing catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL), as well as malondialdehyde (MDA) content during the production process of induced resistance were also measured. [Result] SA had no inhibitory effect against spore germination and mycelial growth of B. cinerea within the concentration range, and the relative induced effect had different degrees of improvement after treatment. The induced effect was the best as B. cinerea was challenged to inoculate at the third day after using 150 mg/L SA in tomato plants, and the duration of resistance was 10-15 d. After treated by SA, CAT, POD, PPO and PAL first increased and then decreased in systemic induced resistance against B. cinerea, which were significantly higher than control. Meanwhile, MDA content showed ascendant trend in wavy line form. [Conclusion] The use of SA within a certain concentration range is safe; CAT, POD, PPO and PAL activities have positive correlation with induced resistance against B. cinerea, the increase of MDA content also has close relationship with the improvement of disease resistance.