华南地区六种蕨类植物耐旱性研究

利用盆栽控水法研究了华南毛蕨、蜈蚣蕨、线羽凤尾蕨、毛叶铁线蕨、长叶肾蕨和普通针毛蕨6种华南地区常见蕨类的耐旱性,测定了植株在自然干旱下的土壤绝对含水量、叶绿素SPAD值、叶片相对含水量和气体交换参数等指标变化。结果表明:随干旱胁迫加剧,叶片相对含水量总体呈下降趋势,其中普通针毛蕨、蜈蚣蕨和长叶肾蕨下降不明显,华南毛蕨降幅最大。叶绿素SPAD值随干旱加剧显著下降,其中华南毛蕨和长叶肾蕨下降幅度较小,蜈蚣蕨下降幅度较大。净光合速率、气孔导度和蒸腾速率随干旱加剧而不断下降,其中普通针毛蕨和蜈蚣蕨下降幅度较小,华南毛蕨下降幅度较大。然而,胞间CO2浓度随着干旱的加剧而不断上升,其中线羽凤尾蕨上升幅度最大,蜈蚣蕨和普通针毛蕨上升幅度较小。以各指标的平均变化速率为原始数据进行隶属函数法分析得出,六种参试蕨类植物的耐旱能力大小依次为蜈蚣蕨普通针毛蕨长叶肾蕨毛叶铁线蕨华南毛蕨线羽凤尾蕨。

Drought-resistance capability of six ferns from South China

The drought-resistance capability of Cyclosorus parasiticus, Pteris vittata, P. linearis, Adiantum pubescens, Nephrolepis biserrata and Macrothelypteris torresiana in South China was studied under the condition of artificial soil desiccation in this paper, and indexes of absolute water content, relative water content, chlorophyll content SPAD value and photosynthetic parameters were measured under drought-stress condition. The results showed that as drought stress increased, the absolute water content of six ferns decreased generally, Macrothelypteris torresiana, Pteris vittataand, Nephrolepis biserrata decreased slightly, and Cyclosorus parasiticus decreased the most. SPAD value decreased as drought stress increased, C. parasiticus and Nephrolepis biserrata decreased slightly, the reduction of Pteris vittata was significantly larger than that of the others. Net photosynthetic rate, leaf transpiration rate and stomatal conductance decreased as drought stress increased. With the increase of intercellular CO₂ concentration, Macrothelypteris torresiana and Pteris vittata decreased less, Cyclosorus parasiticus decreased largely, while Pteris linearis increased, Macrothelypteris torresiana and Pteris vittata increased slightly. The drought resistance of six ferns was evaluated by membership function method based on the average rate of change in indexes. The drought resistance order was Pteris vittata > Macrothelypteris torresiana > Nephrolepis biserrata > Adiantum pubescens > Cyclosorus parasiticus > Pteris linearis.