Relationship Between the Activity of Four Defense Enzymes in Leaf and Phytophthora-resistant of Pepper

Taking three near-isogenic lines with different phytophthora resistance as the experimental material,the activities of four enzymes(β?1,3-glucanase,chitinase,PAL,POD)were detected after induced by race 3of Phytophthora capsici.The relationship between the activity of four defense enzymes in leaf and phytophthora-resistant of pepper was studied.The results showed that the activities of four defense enzymes in pepper's leaves were increased by infection of Phytophthoracapsici,the rate of enzyme activity forβ?1,3-glacanase,chitinase,PAL,POD in resistant lines after infection of Phytophthora capsici was 164.4%,99.1%,173.7%,107.6%;but in susceptible lines was 91.8%,48.1%,93.1%,64.0%,the increase in activities was faster and higher,and lasted longer in a resistant lines than that in susceptible lines.The activities of enzymes in mid-resistant lines were between two of above.The results suggested thatβ?1,3-glacanase,chitinase,PAL and POD could be induced by Phytophthora capsici and the relationship between the activities of the four enzymes and the resistance of pepper was positive.In the resistant line,the rate of enzyme activity forβ?1,3-glacanase was1.66 times higher than chitinase;PAL was 1.61 times higher than POD.The inhibition ofβ?1,3-glacanase and chitinase to mycelia growth and sporangia formation were observed.β?1,3-glacanase was significantly higher than that of control,chitinase showed no clear inhibition to Phytophthora capsici.