甘薯茎叶中花青素的定位及含量测定 Location and Relative Quantity of Anthocyanidin in the Aboveground Parts of Sweetpotato

花青素是植物体内一类重要的次生代谢产物，有着显著的生理活性与营养保健功能。本实验通过徒手切片制作临时装片在光学显微镜下观察了甘薯栽培品种徐紫薯3号地上各部位花青素的分布情况，并测定和比较了20种不同甘薯品种地上部分的花青素相对含量及对DPPH·自由基的清除能力。结果表明花青素主要分布于叶的表皮细胞、茎和叶柄的表皮细胞及韧皮部的薄壁细胞中，在茎的髓部薄壁细胞中也有分布；茎叶中花青素含量在基因型间存在一定差异。甘薯茎叶部可作为人们获取抗氧化活性物质的重要来源之一。 Anthocyanidin is one of the most important groups of secondary metabolites in plants with prominent physiological activity and healthcare function. In this study, distribution of anthocyanidins in blade, petiole and stem in sweetpotato cv. Xuzishu 3 was observed through light microscope. Relative contents of anthocyanidin and free radical scavenging activity were also measured in 20 varieties sweetpotatos. The results indicated that anthocyanidins located mainly in epidermic cells of leaves, epidermic cells and phloem parenchymal cells of petioles and stems, parenchymal cells of piths. The data of anthocyanidins contents revealed that difference existed among the aboveground parts of different cultivar sweetpotatos. This study provided the reliable scientific material for exploitation of the aboveground parts of sweetpotato.