枫香秋季变色期叶色变化及其生理基础

为探究秋季枫叶呈色的关键生理因素,该文以转色期叶色为绿色、黄色和红色的枫香单株为试材,研究了L^*、a^*、b^*值变化与叶片色素、可溶性糖及可溶性蛋白质含量变化的相关性。结果表明:(1)在变色期,3种色彩枫香叶片叶绿素a、叶绿素b、总叶绿素和类胡萝卜素均大量降解,花色素苷不同程度积累。(2)绿色叶单株叶绿素和类胡萝卜素始终保持较高含量,花色素苷含量上升4.2倍,叶片内色素含量比值始终保持稳定; 黄色叶单株叶绿素和类胡萝卜素含量最低,花色素苷含量上升4.4倍,b^*值与叶绿素含量极显著负相关,与类胡萝卜素含量显著负相关,与花色素苷/类胡萝卜素含量比值极显著正相关; 红色叶单株叶绿素和类胡萝卜素含量略高于黄色叶单株,花色素苷含量上升27.2倍,a^*值与叶绿素含量、类胡萝卜素含量极显著负相关,与花色素苷含量显著正相关,与色素含量比值无显著相关性。(3)红色叶单株具有较高的可溶性糖含量和可溶性蛋白质含量。因此,在枫香叶片变色期,保持较高的叶绿素和类胡萝卜素含量,维持色素含量比值稳定使叶片呈现绿色; 叶绿素和类胡萝卜素的大量降解,以及花色素苷/类胡萝卜素含量比值的升高使叶片呈现黄色; 叶绿素的降解和花色素苷的大量合成使叶片呈现红色。

Physiological basis of Liquidambar formosana leaves during leaf color transformation in autumn

To investigate the key physiological mechanisms of leaf colorization of Liquidambar formosana in autumn, the plants with three leaf colors(green, yellow and red)were used as the experimental material. The contents of leaf-color parameters(L^*, a^*,b^*), pigment, soluble sugar and soluble protein were determined, and their correlations were analyzed. The results were as follows:(1)During leaf discoloration period, the contents of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids were greatly decreased, and anthocyanin content was accumulated in large quantities.(2)The contents of chlorophyll and carotenoids remained high in the green-colored leaves, and the anthocyanin content increased by 4.2 times, and the proportion of pigment remained stable. The contents of chlorophyll and carotenoid were the lowest in yellow-colored leaves, and the anthocyanin content increased by 4.4 times. The leaf-color parameters b^* content was significantly negatively correlated with the contents of chlorophyll and carotenoid, but significantly positively correlated with the ratio of anthocyanin to carotenoid. The contents of chlorophyll and carotenoid in the red-colored leaves was slightly higher than the yellow-colored leaves, and the anthocyanin content increased by 27.2 times. The leaf-color parameters a^* content was significantly negatively correlated with contents of chlorophyll and carotenoid, and significantly positively correlated with anthocyanin content, but not significantly correlated with the ratio of pigment.(3)The contents of soluble sugar and soluble protein were higher in the red-colored leaves. The contents of chlorophyll and carotenoid were kept high to keep the green leaves during the discoloration period, and the pigment ratio remained stable. Extensive degradation of chlorophyll and carotenoids, and the increasing ratio of anthocyanin to carotenoid results in yellow leaves. Chlorophyll degradation and anthocyanin synthesis results in red leaves.