5种野牡丹属植物花色素成分及影响花色呈色因子分析

为明确野牡丹属(Melastoma L.)植物花瓣的色素成分和呈色机理，为花色育种提供参考。以野牡丹(M.candidum)、白花野牡丹(M.candidum f.albiflorum)、印度野牡丹(M.malabathiricum)、白花印度野牡丹(M. malabathricumvar.alba)、毛稔(M.sanguinrum)5种野牡丹属植物材料，采用目测法、RHSCC比色法和色差仪测定花瓣表型，应用化学显色法、紫外分光光度法对花色素成分及含量进行初步分析与测定，通过徒手切片组织切片法观察花瓣表皮细胞的显微结构和分布特点，测定花瓣pH值、可溶性糖及可溶性蛋白含量等生理指标分析对花色的影响。结果显示，野牡丹属植物花瓣不含叶绿素和类胡萝卜素，紫罗兰色系主要含花青素苷和黄酮类化合物，白色系主要含黄酮类化合物。野牡丹和毛稔花色素分布于上、下表皮，印度野牡丹花色素分布于上、下表皮和栅栏组织，白花野牡丹和白花印度野牡丹花瓣没有发现色素积累；紫罗兰色系野牡丹上表皮细胞呈圆锥形突起，白色系野牡丹上表皮细胞呈不规则的扁平状，它们下表皮细胞全呈不规则的扁平状。野牡丹属植物花色明度L*随花瓣颜色变深而降低，明度L*与红度a*呈极显著负相关、与蓝度b*呈极显著的正相关。花瓣中花青素苷含量与其明度L*和蓝度b*呈显著负相关，pH值与花瓣红度a*呈现显著的负相关。研究表明，野牡丹属植物花色主要由花青素苷决定，花青素苷含量、色素分布、上表皮细胞形状等是引起花色呈现多样的主要因子。

Analysis of Anthocyanin Composition and Color Factors in Five Species of Melastoma

Abstract: This article in order to clarify the pigment composition and color mechanism of flower petals of Melastoma L., and to provide reference for flower color breeding. We analyzed the anthocyanin pofiles With M.candidum, M.candidum f.albiflorum, M.malabathiricum, M. malabathricumvar.alba, M.sanguinrum 5 cultivars of Melastoma L.The phenotypes of petals were determined by visual method, RHSCC colorimetry and chromaticity analyzer. The components and contents of anthocyanidins were analyzed by chemical colorimetry and ULTRAVIOLET spectrophotometry. The microstructure and distribution of petal epidermal cells were observed by freehand sectioning, and the effects of pH value, soluble sugar and soluble protein content on flower color were analyzed. The results showed that chlorophyll and carotenoids were not contained in the petals of the Melastoma L., anthocyanin and flavonoids were mainly contained in the violet color Melastoma and flavonoids in the white color. The anthocyanins of M.candidum and M.sanguinrum were distributed in the upper and lower epidermis ,and aslo palisade tissue of M.malabathiricum, and no pigment accumulation was found in the petals of M.candidum f.albiflorum and M. malabathricumvar.alba. The upper epidermal cells of violet color Melastoma are conical, and the white color Melastoma are irregular and flat, and the lower epidermal cells are irregular and flat. The color lightness L* decreased with the darker petal color, and was negatively correlated with the redness a* and positively correlated with the blueness b*. There was a significant negative correlation between anthocyanin content and brightness L* and blueness b*, and a significant negative correlation between pH value and redness a*. Research shows, anthocyanin content, pigment distribution and shape of upper epidermis cells are the main factors that cause the variety of flower color.