金桂及其芽变花色表型及色素成分分析

Flower Color and Pigment Composition in the Petals of Bud Mutation and its Stock Plant of Osmanthus fragrans ‘Jingui’

以金桂及其芽变花为试验材料,利用英国皇家园艺学会比色卡(Royal Horticultural Society Color Chart,R.H.S.C.C.)和色差仪测量两种花的颜色表型,通过显色法和紫外—分光光度计初步确定了两种花的主要色素类型,并且利用高效液相色谱—光电二极管阵列(HPLC–DAD)测定花瓣中类胡萝卜素和总黄酮含量,利用高效液相色谱—大气压化学电离源—质谱联用技术(HPLC–APCI–MS)和标准品鉴定主要类胡萝卜素成分。结果发现,芽变枝条上的花色由母本的黄色(R.H.S.C.C.12B^13A)变为橙红色,且花瓣边缘和内部颜色不同(内侧R.H.S.C.C.23B,花瓣外缘R.H.S.C.C.N25A);两种花瓣中均含黄酮类化合物,不含花青素苷,且两者的类胡萝卜素含量存在一定差异;从两种花瓣中分离鉴定出主要的类胡萝卜素成分为α–胡萝卜素和β–胡萝卜素,这两种组分和类胡萝卜素总量在芽变花瓣中极显著高于母本,而两种花瓣的总黄酮含量无显著性差异。因此,最终可以确定引起芽变花色变化的主要色素成分为类胡萝卜素。

The flowers from stock plant and bud mutational branches of Osmanthusfragrans ＇Jingui＇ were used for this research. First, the Royal Horticultural Society Color Chart（R.H.S.C.C. ）and colorimeter was used for the measurement of the phynotype parameters. The pigment types were preliminary identified with the method of color reaction and UV - Vis analysis. The HPLC - DAD was used to measure the contents of carotenoids and total flavonoids. The dominate carotenoid components were further identified by the HPLC- APCI- MS and standards. The results showed that the flower color of the mutational branches became into reddish orange （inside： R.H.S.C.C. 23B; outside： R.H.S.C.C. N25A）, which was different from the yellow color （R.H.S.C.C. 12B - 13A） of the flowers from stock plant. Furthermore, it was comfirmed that both of these two kind petals contained flavonoids, but without anthocyanins, and different content of carotenoids. Finally, α-carotene and β-carotene were detected as the main carotenoid components in the petals of the two kind flowers. The content of α-carotene, β-carotene and total carotenoids in the petals of the mutational branches were significant higher than those in the petals of stock plant, whereas there was no significant difference between the total flavonoid content of two samples. Therefore, carotenoids were considered as the dominate pigments which led to the change of flower color of mutant.