Improving Drought Resistance of Pepper (Capsicum annuum L.) through Drought Hardening

In order to ascertain physiological reaction of the pepper (Capsicum annuum L.) under water stresses, we conducted cycling drought hardening on pepper seedlings raised on floating trays by the circle of "water control-half wilting-rehydration-recovery". The results showed that short period drought stress could inhibit the formation of the chlorophyll in pepper leaves. However, the activities of protective enzyme system (SOD, POD) were gradually strengthened and especially the content of MDA increased obviously. Meanwhile, short period drought stress could obviously increase the content of soluble sugar in leaves and decrease cell osmotic potential in leaves. Compared with control, the drought-hardened seedlings could accumulate more soluble sugar and maintain higher pressure potential through decreasing osmotic potential in leaves than seedlings without drought hardening, when they were subjected to subsequent drought. Thus, drought hardening can increase drought resistance of pepper.