两个牡丹品种开花过程中花色变化的研究

采用英国皇家园艺学会比色卡（RHSCC）、色差仪、组织切片法及高效液相色谱-二极管阵列检测技术（HPLC–PAD）对牡丹品种‘金衣花脸’和‘霞光’开花过程中花色变化、色素的分布及组成和含量的变化进行研究。从两个品种花瓣（不含色斑部位）中共检出4种花青素和14种黄酮类色素，主要分布在花瓣表皮细胞内，中部栅栏组织无或仅有少量黄酮类色素。两个品种开花过程中花色明度增加，彩度降低，红色减退，分别由红黄复色和红色变为浅黄色和橙黄色。开花过程中色素组成不变，色素含量变化明显，总花青素和总黄酮含量均呈逐渐降低趋势，且总花青素含量降低幅度更大。开花过程中花青素和黄酮的降解速率不同，使得花色逐渐由红色向橙色至黄色变化。

Preliminary Studies on the Changes of Flower Color During the Flowering Period in Two Tree Peony Cultivars

In this paper，we explored the flower color variation，pigments distribution and content during the flowering period in tree peony cultivars named‘Jinyi Hualian’and‘Xiaguang’respectively using Colour Chart of the Royal Horticultural Society（RHSCC）and colorimeter，tissue sections，and high performance liquid chromatography with a photodiode array detector. Four kinds of anthocyanins and 14 kinds of flavonoids were detected from two tree peony cultivars. They are mainly distributed in epidermal cells，whereas no or only a few flavonoids were found in palisade tissue. Our results suggested that the flower lightness（L*）of the two cultivars increase，whereas the chroma（C*）and redness decrease during flowering period with the flower color changing from red yellow bi-color and red to light yellow and orange yellow respectively. The pigments composition of two cultivars remained unchanged during this period；but there was a significant change in pigment content. Total anthocyanins（TA）and total flavonols （TF）decreased sharply；And the content of TA decreased sharper compared with TF. Overall，the results indicated that the difference in anthocyanins and flavonoids degradation rates during the flowering periodhad caused the color to change from red to orange and yellow，and could be the main contributing factor for changes in flower color.