Study On The Effects And Mechanism Of Chemical Elicitors Induced Resistance To Honeysuckle Powdery Mildew

The effects on the growth of spore germination of Microsphaera linicerae by different chemical elicitor were tested in the room. The name and concentration of medicament tested are as follows: oxalic acid (1g/LX SA (0.5g/LX chitosan (1g/L), dextran (2g/L), ferrous sulfate (5g/L). K₂HPO₄ (5g/L), sodium silicate (1.5g/L), Trifluralin(5ml/L).These elicitors at above concentration have less inhibition to spore germination of Microsphaera linicerae.The effects of induced resistance of eight chemical elicitors to powdery mildew on Honeysuckle were investigated in different growth ages Honeysuckle. The experiment results show that the chitosan can induce Honeysuckle resistance primely; oxalic acid , ferrous sulfate, sodium silicate can induce the resistance in some degree too; the SA had some effect on the special growth age Honeysuckle, but it was not invariableness. dextran and K₂HPO₄ had inferior effect, or, could make disease severe. Trifluralin could make disease severe on every growth ages Honeysuckle. Anyhow, the chemical elictors can induce the resistance on one-year Honeysuckle better, the effects of the chitosan, SA, ferrous sulfate, oxalic acid and sodium silicate were 82.3%, 70.0%, 68.8%, 54.9% and 52.3% respectively, and on the four-year Honeysuckle, the effects of oxalic acid, chitosan and sodium silicate were 74.1%, 72.1% and 54.8% respectively. The effects of all the chemical elicitors on the two-year Honeysuckle were worst.The physiobiochemical activities after induced treatment by chemical elicitors in Honeysuckle were tested. The results showed that activities of phenylalanine aminolyase(PAL) , peroxidase(POD) and Polyphenol Oxidase(PPO) changed in different degrees. The PAL, POD, PPO all increased or reached the peak after chitosan treated one day and they would keep a stable level after they reached the other peak. However, the other treatment were not like this. Seen from PAL, the activity reached a peak with 10.05U/g.h and reached another peak with 14.03 U/g.h on the fifth day after a degressive stage. At the same time, the activity keep changeless and was better than other treatment and CK. But other treatment and CK were approximate; from the PPO, only the activity of chitosan treatment was better...