The Effects Of Ornamental Plants On Removing The Indoor Pollutant Formaldehyde And Their Tolerance To Formaldehyde Stress

In recent years, with the improvement of people's living standard, more and more people pay attention to improving the environment around them. Among the indoor harmful gases, formaldehyde is classified as a major pollutant and is called invisible killer in living room. Indoor harmful gases can be removed by plants, although the abilities of different species of plants in removing harmful gases and their tolerances to those harmful gases are very different. Therefore, evaluating the abilities of plants in removing indoor harmful gases is of great significance. In this paper, the abilities of 50 indoor ornamental species and 14 Hedera cultivars in purificating formaldehyde pollutant and their tolerance to formaldehyde stress were evaluated by using formaldehyde gas capsule fumigation method. Meanwhile, the effects of different temperatures, light levels, and seasons on the plants' formaldehyde removal ability were investigated. Main results are as follows:1. All the 50 ornamental species had abilities to absorb formaldehyde pollutant, and the removal capacities of different plants were different, which ranked from high to low according to the removal capacities:Dianthus caryophyllus, Lsodon amethystoides, Sansevieria trifasciata'Laurentii', Dendranthema×grandiflorum'Mibaizao', Senecio cruentus, Saivia spp., Ficus elastica, Commelina communis, Dieffenbachia picta'Camilla', Hedera helix, Begonia x hiemalis, Rhododendron hybrida, Scindapsus aureum, Citrus limon, Chamaedorea elegans, Monstera deliciosa. Some plants showed Injury symptoms on leaves after formaldehyde fumigation treatment, while others had no obvious symptoms.The SPAD value and POD ability of most plants showed a different variation after treatment, and the relative conductivity and MDA content were increased to some extent.2. The abilities of 14 Hedera cultivars in absorbing formaldehyde pollutant and their tolerance to formaldehyde stress were different. Among them, the green-leaved cultivars such as'Lady Key'had high removal capacity, and spot-leaved cultivars and'Evergreen'had lower removal capacities. Leaf SPAD values of all Hedera helix cultivars increased with increasing fumigation concentration. The relative conductivity and MDA content increased under formaldehyde fumigation treatments. POD activity increased firstly and then decreased with the fumigation concentration increasing. Cha, Chb and carotenoids content decreased, while the ratio of carotenoid and chlorophyll content increased.3. The formaldehyde removal capacities of 4 Hedera helix cultivars and 20 ornamental species increased with environmental temperature increasing (15℃,20℃,25℃), and light intensity increasing (3.0μmol·m-2·s-1,6.0μmol·m-2·s-1, 9.0μmol·m·-2·s-1). For most of tested species, the formaldehyde removal capacities were significantly higher in summer than that in winter, such as Schefflera arboricola, Neottopteris nidus, Nephrolepis exalata'Bostoniensis'and Zebrina pendula. While there was not significant difference for Lsodon amethystoides, Calathea rotundifolia cv. Fasciata and Dieffenbachia picta'Camilla'whose removal capacities were lower in the summer.The results provide a basis for the sciencific use of ornamental plants to decorate the room environment and clean the indoor air environment.