Induced Resistance of Tomato against Gray Mold (Botrytis cinerea) by Salicylic Acid (SA)

[ 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 myce- lial 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 imvrovement of disease resistance.

叶霉菌非亲和小种对番茄系统抗性的诱导及植株内水杨酸动态

番茄叶霉菌小种４ 是番茄Ｃｆ５ 品系的非亲和小种，接种Ｃｆ５ 植株第 ３ 叶后，经不同诱导间隔期以亲和小种５ 接种第３ 叶和第４ 叶，１５ ｄ 后检查叶霉病发病情况。试验表明，在诱导间隔期为３ ｄ 和５ ｄ 时，小种４ 诱导接种的第 ３ 叶和未经诱导接种的上位第 ４ 叶发病面积比不接种或接种小种５ 的对照显著降低，以５ ｄ 间隔期处理效果最好。上述２ 个叶位的发病分别比对照降低９０％ 和８５％ 。小种４ 接种第３ 叶后该叶位和上部未接种第４ 叶内水杨酸含量迅速增加，以接种后３ ｄ 含量最高，分别达４０２ μｇ／ｇ 鲜重和３２１μｇ／ｇ 鲜重，比对照分别高２ 倍和 １８ 倍。接种后５ ｄ 内始终保持较高水平。接种８ ｄ 后逐渐下降，但仍高于对照。水杨酸含量的增加早于抗性表现，因而可能在该系统的抗性诱导中起作用。

水杨酸诱导番茄对灰霉病的抗性研究

[目的]探讨水杨酸(SA)对番茄抗灰霉病的诱导作用。[方法]以SA作为诱抗剂处理番茄幼苗,研究了SA对番茄灰霉病病原菌菌丝生长和分生孢子萌发的影响,并测定了其诱导抗性产生过程中番茄植株体内过氧化氢酶(CAT)、过氧化物酶(POD)、多酚氧化酶(PPO)和苯丙氨酸解氨酶(PAL)4种防御酶活性及丙二醛(MDA)含量的变化。[结果]SA在其浓度范围内对番茄灰霉病病原菌的孢子萌发和菌丝生长无抑制作用,而相对诱导效果在处理后也有不同程度的提高,其中用150 mg/L SA处理番茄植株后间隔3 d挑战接种灰霉病病原菌产生的诱导效果最好,且抗性持续期在10～15 d。经SA处理后,CAT、POD、PPO、PAL在番茄灰霉病系统诱导抗性中均呈先上升后下降的趋势,且明显高于对照,同时MDA含量以波浪线形式呈上升趋势。[结论]SA在一定浓度范围内使用是安全的;CAT、POD、PPO、PAL活性与番茄对灰霉病的诱导抗性呈正相关,MDA含量的增加与抗病性的提高也密切相关。