Guangdong nongye kexue (Jul 2022)
Effect of Indole-3-acetic Acid on the Growth of Ornamental Plants and Efficiency of Heavy Metal Remediation
Abstract
【Objective】The effects of indole-3-acetic acid(IAA) on the growth and heavy metal uptake of ornamental plants were investigated to provide theoretical basis for remediation of soil heavy metal pollution.【Method】With three ornamental plants Impatiens balsamina, Marigold and Coreopsis as tested materials, and the tests were carried out in a farmland in Wentang, Dongguan City. The effects of indole-3-acetic acid(IAA) on the plant height, dry weight and fresh weight as well as Cd, Pb and Hg enrichment of the above-mentioned ornamental plants were investigated.【Result】Resultsshowed that 100 μmol/L could promote the growth of I. balsamina, Marigold and Coreopsis and increased their plant height, fresh weight and dry weight, with significant increases in the stem. The stem fresh weights of I. balsamina, Marigold and Coreopsis were 270.04 g, 63.73 g and 20.05 g, which were increased by 66.6%, 70.1% and 99.1% respectively compared with control groups, and the differences were significant. The stem dry weights of I. balsamina, Marigold and Coreopsis were 14.99 g, 11.96 g and 3.20 g, which were increased by 26.7%, 69.9% and 29.6% respectively compared with control groups, and the differences were also significant. IAA could promote the absorption of Cd by I. balsamina, Marigold and Coreopsis, increase the transfer coefficient of Cd by Marigold and reduce the transfer coefficient of Cd by I. balsamina and Coreopsis; IAA could promote the absorption of Pb by Impatiens balsamina while inhibit the absorption of Pb by Marigold and Coreopsis. IAA had no significant effect on the absorption of Hg by the three plants.【Conclusion】These results indicated that IAA promoted the growth and increased the Cd enrichment of the three ornamental plants, reduced the Pb enrichment by Marigold and Coreopsis, while it had no significant effect on the absorption and transfer of Hg.
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