拟康氏木霉胞外多糖对番茄灰霉病的诱抗作用及对几种防御酶活性的影响

The Effects of Polysaccharides from Trichoderma pseudokoningii on the Activities of Several Defense Enzymes and Resistance of Tomato to Grey Mold

喷施不同浓度(5 0～6 0 0mg/L)的拟康氏木霉的胞外多糖后,番茄灰霉病的发病率明显降低.与植物系统抗性相关酶苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)的活性显著升高,上升幅度随多糖的浓度增加而递增,多糖浓度达到2 0 0mg/L以上时增加趋缓.酶活性在3～4d达到最高,之后有所下降,但仍高于对照.当多糖浓度为2 0 0mg/L时,3种酶的最高活性分别比对照高出12 3%、14 6 %和10 2 % .体外试验未发现该多糖对灰霉菌的生长有抑制作用。

After the tomato seedlings were treated with the polysaccharides (TPS) from Trichoderma pseudokoningii in different concentrations (50～600 mg/L) , the effect of TPS on the activities of defense enzymes and the efficacy in controlling grey mold of tomato were researched. The results indicated that the activities of phenylalanine ammonialyase (PAL ), peroxidase (POD), polyphenoloxidase (PPO) increased and the disease rate of grey mold of tomato decreased after the treatment with TPS. The enzymes activities reached a peak on the 3rd or 4th after the treatment. The enzymes activities rose with the increasing of TPS concentration. When the concentration was 200 mg/L, the highest activities of PAL, POD, PPO increased by 123%, 146%, 102% compared with CK. TPS could significantly protect tomato seedlings against grey mold. As the TPS did not inhibit the growth of mycelial of Botrytis cinerea in vitro, it was inferred that the disease controlling effects of TPS were attributed to induced resistance of plant.