不同品种三角梅开花过程中苞片色彩参数和色素含量的变化特征

Variation characteristics of color parameters and pigment content in bracts at different flowering stages among various cultivars of Bougainvillea spectabilis

【目的】探究不同花色三角梅开花进程中的苞片色彩参数和色素含量的变化特征及其苞片色彩淡化机制。【方法】以橙色系和粉色系三角梅中5个苞片色彩淡化程度明显的品种为材料,利用英国皇家园艺学会比色卡(RHSCC)和色差仪对花蕾期(S1)、盛花期(S2)和末花期(S3)的苞片色彩参数进行测量,采用分光光度计法对其开花过程中苞片色素含量进行测定,并对苞片色彩参数与色素含量变化进行相关性分析。【结果】在开花进程中,5个三角梅品种苞片色彩呈现不同程度的淡化现象,其中橙色系品种‘变色龙’和‘金色光辉’的苞片色彩总淡化程度相对较大,粉色系品种‘中国丽人’‘金边重粉’和‘金发女郎’的苞片色彩淡化程度较小;定量分析结果表明,在开花过程中除‘变色龙’苞片中总黄酮含量高于甜菜色素外,其他4个品种苞片中色素含量从高到低依次为:甜菜色素、总黄酮、叶绿素、类胡萝卜素;苞片色彩参数与色素含量相关性分析结果表明,甜菜色素是影响三角梅苞片色彩变化的主要色素,其中以甜菜红素的影响最大;总黄酮和甜菜黄素是影响橙色系三角梅苞片色彩淡化的主要色素,甜菜红素和总黄酮是影响粉色系三角梅苞片色彩淡化的主要色素。【结论】不同品种三角梅在开花过程中的苞片色彩变化规律存在一定的差异;三角梅苞片色彩参数与色素含量具有一定的相关性,其中,苞片色素的成分变化是影响三角梅苞片呈色和淡化的关键因素。

【Objective】The research was conducted to explore the variation characteristics of color parameters and pigment content and the mechanism of color dilution of bracts at different flowering stages in Bougainvillea spectabilis cultivars with different flower colors.【Method】Five varieties of B.spectabilis with obvious degree of bracts color dilution in orange and pink series were used as materials.The color parameters of bracts at bud stage(S1),fully blooming stage(S2)and final flowering stage(S3)were measured using the Royal Horticultural Society Colour Chart(RHSCC)of the United Kingdom and color difference instrument.The pigment content of bracts during flowering was determined by spectrophotometer,and the correlation between the color parameters and the pigment content of bracts was analyzed.【Result】During the flowering process,the bract color of five varieties of B.spectabilis showed varying degrees of dilution.Among them,orange varieties‘Chameleon’and‘Golden Glow’had relatively large degree of dilution of the bract color,while pink varieties‘China Beauty’,‘Jinbian Chongfen’and‘Blonde Girl’had a relatively small degree of dilution of the bract color.The results of quantitative analysis showed that the total flavonoid content in the bracts of‘Chameleon’was higher than that of sugar beet pigment during the flowering process,and the pigment content in the bracts of the other four varieties was in the order of sugar beet pigment,total flavonoids,chlorophyll and carotenoid from high to low.The correlation analysis between the color parameters and the pigment content of bracts showed that the sugar beet pigment was the main pigment that affected the color change of the bracts of B.spectabilis,and the influence of betacyanin was the largest.Total flavonoids and betaxanthin were the main pigments that affect the color fading of the bracts of orange B.spectabilis,while betacyanin and total flavonoids were the main pigments that affect the color fading of the bracts of pink B.spectabilis.【Conclusion】There are certain differences in the color changes of bracts during the flowering process of different varieties of B.spectabilis.There is a certain correlation between the color parameters and the pigment content of B.spectabilis bracts.The changes in the pigment composition of the bracts are the key factors affecting the color and fading of B.spectabilis bracts.