北美红枫秋季呈色的生理机制研究

为明确3种北美红枫秋季变色期呈色生理差异,进一步阐释北美红枫呈色生理机制,为北美红枫引种选择及适应性栽培提供参考,特对其叶色参数、色素质量比、可溶性糖质量比、可溶性蛋白质量比、相关酶活性、叶片pH值等进行测定,通过单因素方差分析比较三者间差异,并通过相关性分析探寻北美红枫转色关键作用因子.结果表明,色素质量比、可溶性糖质量比、可溶性蛋白质量比、多酚氧化酶(PPO)活性、叶片pH值等是影响北美红枫转红的重要作用因子.苯丙氨酸解氨酶(PAL)活性在北美红枫秋季变色期对色素质量比及色素比例并无明显影响,不是影响其叶色转变的重要影响因子.叶绿素和类胡萝卜素质量比下降是北美红枫转红的原因,但花色素苷质量比迅速增加、m_(Chl)/m_(Ant)值和m_(Car)/m_(Ant)值的迅速降低才是北美红枫转红更为重要的直接原因.北美红枫叶色a值与可溶性糖质量比显著正相关(p0.01),整个秋季变色期,可溶性糖质量比呈不断上升趋势,但可溶性糖过量积累可能会抑制花色素苷合成,进而影响北美红枫叶片转红.北美红枫叶色a值与叶片pH值显著正相关(p0.01),整个秋季变色期,叶片pH值不断升高.

Study of the Mechanism of Physiological Discoloration of North American Red Maple (Acer rubrum L.)

In order to clarify the physiological differences among three varieties of North American red maples (Acer rubrum L.) and further explain the physiological discoloration mechanism so as to provide a reference for the introduction and adaptive cultivation of red maples in southwestern China, a study was conducted in which the leaves of the three varieties were collected to measure their leaf color parameters, pigment contents, soluble sugar contents, soluble protein contents, the related enzyme activities and leaf pH values. Finally, one-way ANOVA was used to analyze their differences, and correlation analysis was used to explore the key factors of autumn color change of A. rubrum. The results showed that pigment, soluble sugar, soluble protein, PPO activity, and leaf pH were important factors influencing the leaf color of A. rubrum in autumn. PAL had no significant effect on pigment content, pigment ratio and leaf color parameters, so it was not an important factor affecting leaf color transformation of A. rubrum. While the decrease of chlorophyll content and carotenoid content was one reason, the rapid increase of anthocyanin content, the rapid decrease of Chl/Ant value and Car/Ant value had a much more direct influence on leaf discoloration. The "a" value of red maple leaf color was in a highly significant positive correlation with soluble sugar content (p<0.01). The soluble sugar content increased continuously during the autumn discoloration period, however, excessive accumulation of soluble sugar might inhibit anthocyanin synthesis. The leaf pH value increased continuously throughout the autumn discoloration period. There was a highly significant positive correlation between "a" value and leaf pH value (p<0.01).