基于叶性状的蕨类植物生理生态策略分析

Analysis of Eco-physiological Strategies of Fern Species Based on Leaf Traits

摘要:

为阐明蕨类植物对环境变化的适应性，该研究选择热带、亚热带30种典型地生蕨类植物，测定叶(羽片)形态结构、机械抗性和水分关系性状，并以同区域54种木本被子植物的相关性状为参照，结合系统发育和性状网络分析蕨类植物叶性状的相关关系。结果表明，与木本被子植物相比，蕨类植物穿刺力(F_p)较小，抗栓塞能力(P50_leaf)较弱，膨压丧失点(Ψ_tlp)较高，说明蕨类植物对机械伤害和水分胁迫的抵御能力较低。蕨类植物叶片饱和含水量(SWC)与Ψ_tlp和P50_leaf显著正相关，说明蕨类植物通过提高叶贮水能力权衡其较弱的耐旱能力；被子植物SWC与P50_leaf不相关。被子植物叶片F_p与比叶质量、叶厚度以及最大导水率均显著正相关；蕨类植物F_p仅与叶厚度显著正相关，且两者协同进化。因此，不同植物类群对环境适应策略具有多样性。

Abstract:

To clarify the adaptability of ferns to environmental changes, thirty typical terrestrial fern species were selected from tropical and subtropical regions, measured their leaf (pinna) morphological structure, mechanical resistance and water relationship traits, and used the corresponding traits of 54 woody angiosperms in the same region as a reference. Combined with phylogenetic and trait network analysis, the correlations of leaf traits in ferns were analyzed. The results showed that compared with woody angiosperms, ferns had lower puncture force (F_p), weaker embolism resistance (P50_leaf), and higher turgor loss point (Ψ_tlp), indicating that ferns had lower resistance to mechanical damage and water stress. The saturated water content (SWC) of fern leaves was significantly positively correlated with Ψ_tlp and P50_leaf, suggesting that ferns balanced their relatively weak drought tolerance by increasing leaf water storage capacity; the SWC of angiosperm leaves was not correlated with P50_leaf. The F_p of angiosperm leaves was significantly positively correlated with leaf mass per area, leaf thickness and maximum leaf hydraulic conductance; the F_p of ferns was only significantly positively correlated with leaf thickness, and the two evolved in concert. Therefore, different plant groups have diverse strategies for adapting to the environment.