遮荫对高山羊齿光合生理特性的影响

Effect of Shading on Photosynthetic Physiological Characteristics of Davallia mariesii

摘要:

为揭示高山羊齿（Davallia mariesii）的光响应机制，对5种不同遮荫处理的盆栽高山羊齿的生长状态、光合特性和叶绿素荧光参数进行测定。结果表明，随着遮荫水平的增加，高山羊齿叶形不断变大、叶色不断加深。在70%遮荫下，高山羊齿生长势好，叶片硬脆有光泽，且产孢率低，孢子成熟延迟。叶绿素a、叶绿素b和叶绿素a+b随遮荫水平的提高而增加，但在90%遮荫时下降；而叶绿素a/b、光饱和点、光补偿点和暗呼吸速率的变化则与之相反，且遮荫程度较深与无遮荫间的光饱和点有极显著差异。在5种遮荫处理下，70%时叶绿素荧光参数Fm、φ_Po、ψ_O、φ_Eo、TR_O/RC、ABS/RC、ET_O/RC都达到最大。因此，70%遮荫的光抑制最小，光能利用率最大，光合能力最强，最有利于高山羊齿的生长。

Abstract:

In order to reveal the light response mechanism of Davallia mariesii, the growth, photosynthetic characters and chlorophyll fluorescence parameters were measured under five shading treatments, including 0, 25%, 50%, 70% and 90% shading. The results showed that the leaf type became large and leaf color deepened with the increment of shading. Under 70% shading, the growth vigor of D. mariesii was good with hard glossy leaves, low sporulation rate, and spore maturation delay. The contents of chlorophyll a, chlorophyll b and Chlorophyll a+b increased with increment of shading, but decreased under 90% shading, the chlorophyll a/b, the changes in light saturation point, light compensation point and dark respiration rate were opposite, there was significant difference in light saturation point between deep shading and nature light. Among five shading levels, the chlorophyll fluorescence parameters, such as Fm, φ_Po, ψ_O, φ_Eo, TR_O/RC, ABS/RC, and ET_O/RC, reached up to the maximum under 70% shading. Therefore, D. mariesii had the smallest light inhibition, the largest light energy utilization, and the strongest photosynthetic capacity under 70% shading, so that it was helpful for the growth of D. mariesii.