深圳7种园林植物叶绿素荧光特性及其对大气SO2浓度的响应

叶绿素荧光信号能快速灵敏地反映植物生理状态及其与环境的关系,是一种理想光系统探针。测定了深圳市7种园林植物叶片的叶绿素荧光参数和叶绿素含量,并对这些生理参数与大气污染物SO₂的相关性进行了分析。结果表明,7种植物叶片的叶绿素含量具有明显的种间差别,生境的差别远小于种间差别。所测定的7种园林植物的F_v/F_m相差不大,平均为0.78,低于理想条件下的最大值,说明存在一定的生长胁迫。叶绿素荧光的光化学淬灭qP的种间差别不明显。非光化学猝灭系数qN的种类差别较大,白兰Michelia alba和短穗鱼尾葵Caryota mitis具有较高的非光化学淬灭能力,说明这两个种具有一定的光保护能力。7种植物中,白兰的ΦpsⅡ要明显地较低于其它植物。深圳大气污染对城区植物的生理生化特性尚未构成不良影响,在深圳市区的环境中,短穗鱼尾葵、勒杜鹃Bougainvillea spectabilis和阴香Cinnamomum burmanii的叶绿素荧光参数可以作为大气污染物的指示指标;大红花Hibiscus rosa-sinensis、九里香Murraga paniculata、白兰和黄叶假连翘Duranta cv Golden Leaves具有相对较高抗污染物的能力。植物的叶绿素荧光参数也在一定程度上受到叶绿素的影响,阴香、短穗鱼尾葵、大红花和九里香的部分叶绿素荧光参数与植物叶片叶绿素含量呈正相关。

Chlorophyll fluorescence of seven species of gardens plants and their responses to atmospheric SO2 concentration in Shenzhen

In this study,sulfur content of the leaves and chlorophyll fluorescence of 9 garden plant species from Shenzhen were measured in November 2005 to evaluate effect of atmospheric SO₂ in order to select bio-indicators for atmospheric SO₂ monitoring. These plant species include Excoccaria cochinchinensis,Sanchezia nobilis,Codiaeum variegatum,Saruma henryi,aryota mitis,Ficus microcarpa var.pusillifolia,Ficus altissima,Pittosporum tobira and Duranta repens cv.'Dwarf Yellow'. Leaves from the 9 plant species were treated with distilled water and NaHSO₃,their sulfur contents and chlorophyll fluorescence were measured under light or dark conditions at temperature of 25℃. In the natural condition,the sulfur content in leaves of Sanchezia nobilis was the highest,and that for Codiaeum variegatum was the lowest. The sulfur contents of leaves treated with distilled water from the 9 species showed small change. When treated with NaHSO₃,the sulfur contents in sevenof the 9species increased,especially in the leaves of C.variegatum. The same 9 species were collected from two gardens where the atmospheric SO₂ concentration is different: Small Nan Hills with high air SO₂ and World Exhibition Park with low air SO₂. Except for P.tobira,the other 8 species had higher sulfur contents and lower F_v/F_m in Small Nan Hills than in the World exhibition Park. This result demonstrates that F_v/F_m of the 9 plant species is a suitable parameter to indicate pollution from atmospheric SO₂.