不同叶色三叶海棠叶片成色色素分析

Pigment analysis on different colors of leaves from Malus sieboldii

三叶海棠秋季叶色丰富,观赏价值良好。该研究以三叶海棠叶色差异明显的绿色、黄色、红色系的叶片为材料,利用紫外—可见分光光度法、高效液相色谱法对色素进行了定性定量检测,并分析了叶色变化的原因。结果表明:三叶海棠叶片中的色素主要有叶绿素、类胡萝卜素和花青苷,其中花青苷主要是矢车菊素半乳糖苷。绿色系叶片中的叶绿素含量与所占比例显著高于红色和黄色系叶片,而花色素苷和类胡萝卜素所占比例均最小;红色系叶片中的花青苷含量高于其它色系的叶片,花青苷所占比例高于叶绿素与类胡萝卜素所占比例;黄色系叶片中类胡萝卜素含量相对较高,花色素苷和叶绿素所占比例位于绿色与红色系之间。该研究结果表明三叶海棠秋季叶色变化最直接的原因是色素含量与比例发生变化;叶片含有的原花青素B1、芦丁、绿原酸等单体酚作为辅色素对叶片成色起到辅助作用;三种色系叶片中的总黄酮含量由高到低依次为红色、黄色、绿色。

Malus sieboldii is a kind of plant with great ornamental value for its abundant colors in the autumn. Green,yellow and red leaves of M. sieboldii with obvious difference in leaf color were taken as experimental materials. The species and contents of pigments were detected by UV photo-spectrometer and HPLC-DAD and the relevant causes of leaf color change were analyzed afterwards. The experimental results indicated that the main pigments in the leaves of M. sieboldii were chlorophyll,carotenoid and anthocyanin（ mainly Cyanidin-3-galactoside）. In red leaves of M. sieboldii,the coloration was significantly related to the changes in anthocyanin content,whereas the coloration of yellow leaves was closely related to changes in chlorophyll content,as well as changes in the chlorophyll and carotenoid ratio. On the other hand,green coloration in the green leaves of M. sieboldii was attributed to extremely high chlorophyll content. Color changes of M. sieboldii leaves during fall could be attributed to multiple factors,and the most direct factor was the change of pigment content and ratio. As auxiliary pigments,mono-phenols were found to play a supporting role in the fineness of leaves. Furthermore,the total flavonoids content（ from high to low） were red,yellow and green in three species of leaves of M. sieboldii.