2种光强下生长的4种木本植物叶片的光保护物质积累能力与光合能力的关系

摘要:本文研究了两种不同光强下生长4种南亚热带森林优势树种:木荷（Schima superba）、黧蒴（Castanopsis fissa）、黄果厚壳桂（Cryptocarya. concinna）和肖蒲桃（Acmena acuminatissima）幼叶和成熟叶的光保护物质积累能力和其光合能力的关系，结果表明:无论是全光照还是遮阴下生长，4种木本植物成熟叶的叶绿素（Chl）含量和光合作用速率显著高于幼叶，而花色素苷、类黄酮、总酚、总抗氧化能力和类胡萝卜素/叶绿素（Car/Chl）比值都显著低于幼叶. 全光照下生长幼叶的花色素苷、类黄酮、总酚、总抗氧化能力和Car/Chl比值比遮阴高. 显示幼叶的光保护能力很大程度上是依赖于其较高的光保护物质来实现的，如高的花色素苷含量、类黄酮含量、总酚含量以及Car/Chl比值等；随着幼叶的发育成熟这些光保护物质含量逐渐减少而光合能力逐渐增加，因此在幼叶和成熟叶中光保护物质积累能力与光合能力呈现负相关关系.

Relationship between the Accumulation Ability of Photoprotective Substances and the Photosynthetic Capacity in Leaves of Four Woody Plants Grown under Two Light

Abstract: Relationship between photoprotective substances accumulation ability and photosynthetic capacity was studied in leaves of four dominant tree species(Schima superba, Castanopsis fissa, Cryptocarya. Concinna, Acmena acuminatissima) of subtropical forests under two light intensities. Results showed that compare to the young leaves,, the mature leaves exhibited higher chlorophyll (Chl) content and photosynthesis rate but lower anthocyanins content, flavonoids content, phenols content, total antioxidant capacity and carotenoids/chlorophylls (Car/Chl) ratio in four dominant tree species regardless of light intensity. And the young leaves grown under full light conditions exhibited higher total antioxidant capacity and Car/Chl ratio, and contents of anthocyanins, flavonoids, phenols than young leaves grown under shading. The photoprotective ability of young leaves was largely dependent on their higher photoprotective substances, for instance, anthocyanins, flavonoids, phenols, total antioxidant capacity and Car/Chl ratio etc; as the young leaves maturing, these photoprotective substances were gradually reducing and photosynthetic capacity was gradually increasing. Thus, there was a negative correlation between photoprotective substances accumulation ability and photosynthetic capacity in young and mature leaves.