Preliminary Selection of Plants with High Resistance to SO2 for Urban Greening

Abstract:

Seventy-two woody plant species of 1 to 2-year old seedlings were potted at non-polluted site in South China Botanical Garden in Guangzhou. One year later, mature leaves of every species from different individuals were used for experiment of simulation of SO2 pollutant by immersing leaf discs in 20 mmol L^-1 NaHSO₃ solution at 25℃ under 20μ is mol m^-2s^-1 light intensity for 20 h, and in distilled water as control. The treated leaves were conducted for chlorophyll fluorometric assay and for buffer capacity for alkali. The resistance of plants was evaluated comprehensively by decreasing amplitude of the values of Fv/Fm and Fv/Fo after the leaves were treated with NaHSO₃ compared to the control, and by pH value in cell saps and buffering capacity of leaves. Results indicate that the resistant species are Ficus microcarpa var. fuyuensis, Artocarpus nitidus ssp. lingnanensis, Heteropanax fragrans, Tutcheria spectabilis, Ormosia pinnata, Artocarpus hypargyreus, ect., the sensitive species being Dillenia indica, Manglietia glauca, Fagraea ceilanica, Garcinia multiflora, Cassia siamea, etc.