Abstract:

In order to investigate the relationship between plant resistance and plant nutrition,this study measured the change pattern of PAL,PPO,TI and CI activity in needles of Larix gmelinii and L.olgensis with different coning grades.The results showed that when the coning less or no,the two larches had higher activities of defense enzymes and more protease inhibitors, and the enzyme activities and the inhibitors were significantly different from that when the coning performance was in middle or above grade(P<0.05).There were no significant differences in the activity of defense enzyme and protease inhibitor between L.gmelinii and L.olgensis(P>0.05).The results indicated that coning number of larches had the direct impact on the resistance to the pest insects.

Key words: Larix gmelinii, Larix olgensis, coning quantity, plant resistance, defense enzymes, protease inhibitor