不同叶色青钱柳叶片色素、多酚含量及光合特性的差异

【目的】青钱柳是多功能树种,通过比较分析两种不同叶色青钱柳叶片色素、黄酮和单宁两类多酚含量及其光合特性的差异,为青钱柳良种选育提供理论依据。【方法】按照季节动态分别采集红叶青钱柳和绿叶青钱柳的新叶和成熟叶,测定其花色素苷、叶绿素、类胡萝卜素、单宁和黄酮含量,定期测定4种类型叶的净光合速率(P_n)和PSⅡ最大光化学效率(F_v/F_m),并采用单因素方差分析比较不同类型叶间的差异。【结果】红叶青钱柳的新叶花色素苷含量显著高于其他3种类型叶(P<0.05),但叶绿素和类胡萝卜素含量显著低于红叶青钱柳和绿叶青钱柳的成熟叶片(P<0.05);红叶青钱柳和绿叶青钱柳的成熟叶片中的黄酮和单宁含量在多数采样时间均无显著差异(P> 0.05),但在秋季,红叶青钱柳成熟叶片的单宁含量显著高于绿叶青钱柳的成熟叶片(P<0.05);由于红叶青钱柳的新叶积累高花色素苷含量而使总叶绿素含量下降,但其P_n与绿叶青钱柳的新叶不存在显著差异(P> 0.05),红叶青钱柳和绿叶青钱柳成熟叶片的P_n也不存在显著差异(P> 0.05)。【结论】较高浓度的花色素苷是红叶青钱柳新叶呈现红色的主要原因;红叶青钱柳和绿叶青钱柳叶中单宁与黄酮的含量存在一定差异,但总体上差异不显著;红叶青钱柳新叶阶段叶多酚类物质含量较高,但在成熟叶阶段与绿叶青钱柳无显著差异(P> 0.05)。因此,红叶这一表型性状可为青钱柳药用优良单株的筛选提供一定参考,红叶青钱柳在7—8月叶片仍保持较高花色素苷含量而呈现红色,比绿叶青钱柳具有更高的观赏价值。

Variations in the contents of leaf pigments and polyphenols and photosynthesis traits in Cyclocarya paliurus with different leaf colors

【Objective】Cyclocarya paliurus is a multi-functional tree species. To provide a theoretical basis for the breeding of C. paliurus, we examined differences in leaf pigments, flavonoid, and tannin concentrations and photosynthetic traits in two types of C. paliurus with different leaf colors.【Method】Based on seasonal dynamics of leaf growth, young and mature leaves of red-leafed C. paliurus and green-leafed C. paliurus were collected to determine anthocyanin, chlorophyll, carotenoid, tannin, and flavonoid concentration, and net photosynthetic rate (P_n) and PSII maximum photochemical efficiency (F_v/F_m) of the four leaf types. The collected data were analyzed and compared across different leaf types using one-way analysis of variance.【Result】 Anthocyanin concentrations were significantly higher in red fresh leaves (RF) than that in three other leaf types (P < 0.05). However, the content of chlorophyll and carotenoid was significantly lower in RF than those in red mature leaves (RM) and green mature leaves (GM) (P < 0.05); however, the differences between RF and green fresh leaves (GF) were not significant. There were no significant differences between RM and GM regarding flavonoid and tannin content at most sampling times (P > 0.05), whereas the tannin content was significantly higher in RM than in GM in autumn (P < 0.05). RF had a lower total chlorophyll content due to pronounced accumulation of anthocyanins, however, no significant difference in net photosynthetic rates (P_n) between RF and GF (P > 0.05) and between RM and GM were observed (P > 0.05). 【Conclusion】 High anthocyanin concentrations were the main reason for red coloration of RF. There were some differences regarding tannin and flavonoid concentrations between red and green leaves of C. paliurus, but generally no significant difference was observed between them. During the RF phase, the polyphenol content was higher, however, there was no significant difference between red-leaf C. paliurus and green-leaf C. paliurus during most of the mature leaf phase (P > 0.05). Therefore, the phenotypic characteristics of red leaves can only provide a reference for screening superior individuals of C. paliurus for medicinal use. However, in July and August, anthocyanin contents in C. paliurus leaves remained relatively high, and the leaves showed a red coloration, thus showing a higher and relatively stable ornamental value compared with green-leaved C. paliurus.