Effects of five phenolic allelochemicals on growth and enzymes activity of Chuzhou chrysanthemum cutting seedling

An experiment with nutrient solution hydroponics was conducted to study effects of p-hydroxybenzoic acid,cinnamic acid,ferulic acid,vanillin and salicylic acid on growth and enzymes activity of cutting seedlings of Chuzhou chrysanthemum.The results showed that five phenolic allelochemicals at 100 μmol·L-1 concentrations had significant inhibitory effects on root length,and the contents of soluble sugar,soluble protein,chlorophyll a and chlorophyll b in root tissue.The results indicated that POD activity was inhibited,and CAT and SOD activity increased at 10 and 50 μmol·L-1 concentrations of five phenolic allelochemicals,and then decreased at 100 μmol·L-1 concentration,significantly.The content of MDA increased with higher concentrations of phenolic allelochemicals.Compared with the control without phenolic acids,the phenylanlanine ammonialyase(PAL)activity increased at 10 and 50 μmol·L-1,and by contrast,it was inhibited by five phenolic allelochemicals at 100 μmol·L-1.It proved that the poisoning effect of the five phenolic allelochemicals on Chuzhou chrysanthemum growth was caused by the way of inhibiting root length,and it decreased POD,CAT,SOD and PAL activities,and the content of chlorophyll a,chlorophyll b,soluble sugar and soluble protein,whereas increased the content of MDA in root tissue under high concentration.