Cooperative Inducing Effects of Three Plant Growth Regulators on the Chilling Resistance of Sweet Pepper (Capsicum annuum) Seedlings

To study the cooperative inducing effects of coronatine(COR) ,abscisic acid(ABA) ,and mineral fulvic acid(MFA) on the chilling resistance of plants,the sandy culture method was used to identify the effects of mepiquat chloride on the lipid peroxidation,electrolyte leakage,reactive oxygen species and antioxidant enzyme activities in sweet pepper(Capsicum annuum) seedlings under cold stress. Sweet pepper seedlings were irrigated with 10mL per plant of COR,ABA,MFA,and their mixture,respectively. The seedlings were planted at temperature of 10～15℃ for 60d,and then cold stress under 5℃ for 48h. The growth of seedlings and the development of lateral roots were promoted by the mixture. The cooperative inducing effects of three plant growth regulators on the chilling resistance is remarkable. Under cold stress,the activities of antioxidant enzymes such as superoxide dismutase(SOD,EC 1.15.1.1) ,catalase(CAT,EC 1.11.1.6) and peroxidase(POD,EC 1.11.1.7) in leaves were increased. As a result,the efficiency of reactive oxygen species elimination was enhanced. With the higher content of proline and sugar as the effect of abscisic acid in the leaf,the harms of the membrane were relieved by the mixture.