Effects of plant growth regulators on cold tolerance of Zamioculcas zamiifolia

The effects of paclobutrazol and uniconazole on the cold tolerance of Zamioculcas zamiifolia were studied through pot experiment. The results showed that two plant regulators could increase the width, thickness and weight of leaf. They could increase the soluble sugar content, promote the activity of antioxidant enzymes and increase the cellular reactive oxygen scavenging capacity. After being exposed to low temperature stress of 4 to 5 ℃ for 2 days, the differences were found between treated and untreated plants in terms of leaf membrane permeability and Fv/Fm (fluorescence variable/fluorescence maximum). Treated plants had significantly lower leaf membrane permeability and smaller variation of Fv/Fm. It was concluded that paclobutrazol and uniconazole could improve the cold tolerance of Z. zamiifolia.