Studies On Resistance Of Poplar Induced By Methyl Jasmonate

Jasmonic acid plays an important role in induced resistance in plant. Methyl jasmonate(MeJA) solution were sprayed on one-year-old Populus deltoides 895, and assayed the contents of chemical, the activity of enzyme, nutrition metabolism and growing and development of Clostera feeding on treaed leaves, The results are as follows:1. Effects on leaf chemicals of Populus deltotoids treated by MeJAThe content of soluble sugar of treated leaves decreased significantly from 12h to 72h, the free amino acids of treated leaves increased significantly from 4h to 24h, the soluble protein of treated leaves at 24,72h increased significantly. The content of tannins of treated leaves and contra lateral leaves at 4,12,48h increase significantly, the content of phenolic acids of the treated leaves at 24,48h increased significantly. and reaced the peak at 48h, the same changed in contra lateral leaves. The content of Flavonoids of treated leaves increased significantly from4h to 24h, but lateral leaves increased slightly at 4h.2,6-Octadien-1-ol,Pentadecane,Cyclopentane were detected in the volatiles of treated leaf. compared with the contrast. the content of Hexadecanel,2-Benzenediol,2-hydroxy-Benzaldehyde in treated leaves increased to some extent.2. Effects on protective enzyme of leaves of P. deltotoids treated by MeJAAfter MeJA were sprayed on one-year-old P. deltotoids, polyphenol oxidase increased first and then decreased, treated leaves reached the highest at 12h, the lateral leaves increased was not obvious. The lipoxygenase of treated leaves increased significantly at 12,24,72h, the lateral leaves also has an increasing trend and increased significantly at 24,72h. The activity of trypsin inhibitor of treated and lateral leaves increased significantly from 12h to 72h, and the activity chymotrypsin inhibitor of treated leaves only increase significantly at 4h.3. Effects on protective enzymes and detoxifying enzymes of Clostera anastomosis feeding on leaves of P. deltotoids treated by MeJAFeeding on the trated leaves, the POD activity of C. anastomosis have been increasing, increased obviously at 4,24,36h and reached the peak at 36h. CAT activity increased obviously at 12h and then descreased at 36h, The activity has been lower than control at 36,48h., the difference is significantly. SOD activity increased significantly at 36,48h and reached the peak at 48h. GarE activity increased obviously at 4,24,36h and decrease at 48h, but the difference was not significant. MFO activity increased from 4h to 24hand the difference is significantly at 12h. then decreased at 36h, activity has been lower than control at 48h. GST activity increased obviously at 4,12h, the rate of increased is smaller at 48h and the level of activity is similar to the level of control.4. Effects on host selection, nutrition index and growth and development duration of Clostera anastomosis feeding on leaves treated by MeJAAfter feeding on treaed leaves, lavae prefer to health leaves under choice situation. The relative growth rate(RGR) relative consumption rate(RCQ) and the efficiency of conversion of digested food(ECD) reduced significantly, while the efficiency of ingested food(ECI) and approximate digestibility(AD) increased although no significant different between treaed leaves and controls. The development duration of larvae and pupae prolonged, and pupae weight declined, emergency rate and numbe of egg-laying of adults decreased.