Efficacy Of Chemicals On The Resistance Of Vegetables To Anthracanose And The Physiological Mechanism Of Induced Resistance

Efficacy of chemicals on the resistance of vegetables to anthracanose and the biochemical mechanism of induced resistance The efficacy of chemicals on the induced resistance of vegetables to anthracanose and the mechanism of induced resistance were studied. The results showed that among the eight chemicals, salicylic acid (SA) ferulic acid(FA>~ dipotassium phosphate(K2HPO4) and root activator all can induced resistance of cabbages to anthracanose. The effects of induced resistance were different according to the cultivators of cabbage. The resistant cultivator was more easily induced resistance to anthracanose. coumaric acid (CA>. 5K K2HPO4.. FA and root growth promoting agent also could induce resistance of cucumber to anthracanose. But the effects of induced resistance were different according to the concentration of chemicals and the intensity of challenged inoculation. Three chemical such as K2HPO4. CA. each in concentration of 100Mm 5mM can effectively induced systemic resistance of cucumber to anthracanose. Induced treatment could increase resistance by changes of POD PPO. PALS Chitinase~ 13-1 ,3glucnase~ SOD~CAT activities and lignin content. All treatments could increase resistance by increasing PO17PPO~ PAL activities in the first and second true leaf. However, the extent and the time course of increase varied according to the enzymes and inducers during induction and challenge. POD activities treated with K2HPO4 and CA reached a maximum in the third day. After K2HPO4 treatment, PPO activities reached the maximum in the first and fifth day, while the second maximum after CA treatment in the first true leaf was not obvious. PAL activities treated with K2HPO4 and CA reached the maximum in the first day. Induce treatment could induce resistance by increase Iignin content. 47 Ligwn cc~ent in ~ list and aecond mae leaf after iwkictiou was higher than the control. After chalenged inoculation, lignin content in each treatment was higher than before. The increase of lignin content in the induced cucumber was the highest, but the extent was different. K2HPO4 and CA could increase resistance by inducing the activities of chitinase am! bate-i, 3-glucanase systen~cal1y. After induction treatment, the activities of both eni~imes increased in both the first leave and the second third~ fowih leaves. After inoculation, activities increased higher an the control, the activities in the induced cucumber wet-c lower than ~e comror. Both inckacticin treatments could induced resistance by affect Superoxide dismutase (SOD) and catalase (CAT) activities. How they induced resistance of cucimiber to anthracanoae by active oxygen need ~mher te~fied.