Induction effect of mineral fulvic acid on seedling growth and heat resistance in sweet pepper

Sandy culture method was conducted to examine the effects of mineral fulvic acid( MFA) on the seedling growth,lipid peroxidation,electrolyte leakage,reactive oxygen species and antioxidant enzyme activities,such as catalase( CAT),superoxide dismutase( SOD) and peroxidase( POD),in sweet pepper( Capsicum tetragonum) seedlings under heat stress. The growth of seedlings were hastened by MFA obviously. The growth of the seedling irrigated with 500 mg·L-1MFA was promoted by 12.22%( height) or 24. 90%( weight). The efficiency of H 2 O 2 eliminating was increased,and the concentration of malondialdehyde( MDA) was reduced. As a result,the harm of the membrane was mitigated. The activities of antioxidant enzymes such as SOD, CAT and POD in the leaves of the seedling irrigated with 500 mg·L-1MFA were increased by 74. 49%,122.08% and 16.27% separately. It was confirmed that MFA could induce the heat resistance of sweet pepper seedlings and the effective concentration was intervenient between 175 mg·L-1and 500 mg·L-1.