Effects of cold hardening on cold resistance of Spathiphyllum floribundum tissue-cultured plantlets

ObjectiveIn order to provide reference basis for study on physiological and biochemical mechanism relat-ed to cold resistance of Spathiphyllum floribundum,effects of cold harding on physiological and biochemical indexes of S. floribundum tissue-cultured plantlets were studied. MethodWith S. floribundum tissue-cultured plantlets as materials, activities of antioxidant enzymes and contents of soluble protein(SP),proline(Pro),soluble carbohydrates(SS) and malon-aldehyde (MDA) were determined before and after cold harding, in order to analyze cold resistance of S. floribundum tissue-cultured plantlets. ResultResults showed that, activities of superoxide dismutase(SOD),peroxidase(POD),ascor-bic acid peroxidase(APX) and catalase(CAT) in tissue-cultured plantlets increased by 43.0%,47.0%,33.0% and 61.0%after cold hardening(3 ℃) of 72 h,respectively,resulting in improvement of cold resistance of tissue-cultured plantlets. Furthermore, contents of osmotic regulators viz., SP, Pro and SS in leaf increased by 2.0,5.0 times and 70.0%, respec-tively. Meanwhile,cold hardening increased MDA content, resulting in damage of leaf cytomembrane of tissue-cultured plantlets. Activities of antioxidant enzymes and contents of SP, Pro and SS all declined slightly after deacclimation for 1 d, but were higher than those of tissue-cultured plantlet that did not suffered from cold harding. ConclusionCold resistance and transplanting survival rate of S. floribundum tissue-cultured plantlets can be improved by cold harding in actual pro-duction.