荒漠植物通过协同调控叶片形态结构与光合生理适应干旱环境。以四合木、沙冬青、蒙古扁桃与绵刺为研究对象,综合测定叶片形态结构指标与光合生理参数,采用相关性分析和冗余分析解析二者的关系,探究影响光合生理的关键形态调控因子,探讨其在干旱环境下的适应策略。结果表明:1)4种植物叶片形态结构差异显著(P<0.05)。2)4种植物净光合速率日变化均表现出明显的光合午休现象;胞间CO₂浓度随气孔导度减小而降低,气孔调控在环境适应中起主导作用。3)叶片形态结构与光合生理密切相关,叶干物质含量为驱动光合变化的主要形态因子,并对光能利用与水分调控表现出抑制效应。4)不同物种通过差异化的结构与功能协同形成独特适应干旱策略。四合木依赖较高水分利用效率,沙冬青在光能获取与水分保持间达成平衡,蒙古扁桃强化色素体系以增强抗逆性,绵刺则通过利用小的叶面积与高比叶面积实现资源的高效获取。西鄂尔多斯荒漠植物表现出多样化的干旱适应机制,叶干物质含量在调控光合生理中发挥关键作用。

Desert plants adapt to arid environments through the synergistic regulation of leaf morphological structures and photosynthetic physiology.To elucidate the relationship between leaf morphological structures and photosynthetic physiological characteristics and to explore the drought adaptation strategies of typical relict plants in Western Ordos,4 representative species(Tetraena mongolica,Ammopiptanthus mongolicus,Prunus mongolica,and Potaninia mongolica)were investigated.Leaf morphological traits and photosynthetic physiological parameters were comprehensively quantified,and correlation analysis and redundancy analysis(RDA)were employed to elucidate their relationships and identify key morphological factors regulating photosynthetic performance.The results showed that:1)Significant differences in leaf morphology were observed among the 4 species(P<0.05).2)The diurnal variation of net photosynthetic rate in the four species exhibited a pronounced midday depression,and intercellular CO₂ concentration decreased in response to reduced stomatal conductance,indicating that stomatal regulation plays aprimary role in environmental adaptation.3)leaf morphology was intricately correlated with photosynthetic physiology,with leaf dry matter content(c_LDMC)identified as the core driver of photosynthetic variation,exerting an inhibitory effect on both light utilization and water regulation.4)The distinct species have formulated unique drought-adaptation strategies through the differential synergy of structural and functional traits.Specifically,Tetraena mongolica relies on high water-use efficiency,Ammopiptanthus mongolicus strikes a balance between light acquisition and water conservation;Prunus mongolica enhance its pigment system to strengthen stress resistance;and Potaninia mongolica utilizes small leaf area and high specific leaf area to achieve efficient resource acquisition.In conclusion,desert plants of western Ordos exhibit diverse drought-adaptation mechanisms,with c_LDMC playing a pivotal role in regulating photosynthetic physiology.