三角梅苞叶色彩参数和色素含量分析及蓝色转基因受体的筛选

Screening of Blue Transgenic Receptor Varieties in Bougainvillea spectabilis Based on the Analysis of Color Parameters and Pigment Content

三角梅作为重要的观赏植物颜色繁多,但缺乏稀有的蓝色。为筛选适合的蓝色转基因受体,明确不同品种三角梅苞片吸收利用DHM(二氢杨梅素)合成甜菜色素途径竞争产物(类黄酮色素)的潜在能力,该研究对红色、白色、黄色和紫色4大花色6个品种的三角梅苞片进行离体诱导培养,测定诱导培养后苞片色彩参数及色素含量变化,并进行相关性分析。结果显示:(1)三角梅苞片红绿色相值(a*)是决定苞片呈色的主要色彩参数,其色彩主要由甜菜色素和黄酮类色素决定,并以甜菜红素的影响最大。(2)除白色品种三角梅苞片中黄酮类色素含量大于甜菜色素含量外,其余品种苞片发育中甜菜色素含量均呈上升趋势,黄酮类色素呈下降趋势。(3)甜菜色苷含量与苞片a*值呈显著正相关关系,同时与苞片黄蓝色相值(b*)呈显著负相关关系;总黄酮含量与苞片b*值呈显著正相关关系,与苞片a*值呈极显著负相关关系。(4)经DHM体外诱导培养后,苞片总黄酮含量及占比在4个品种三角梅(‘新加坡大白’、‘宝老橙’、‘中国丽人’、‘黄蝶’)中明显升高,但各品种苞片总甜菜色素含量及占比均下降,并以‘新加坡大白’苞片中总黄酮含量上升幅度最大(65.77%),含量占比变化(增加26.91%)也为6个品种中最大。(5)灰色关联度综合分析显示,白色品种‘新加坡大白’与灰色关联度分析拟定的参考品种关联度最高(0.7444),表明三角梅品种中‘新加坡大白’可考虑作为蓝色转基因三角梅的受体品种。

As an important ornamental plant,Bougainvillea spectabilis has many colors but lacks the rare blue color.In order to select a suitable host of genetic transformation that would be suitable for the exclusive accumulation of flavonoid pigment by absorbing dihydromyricetin(DHM)and the resulting color change toward blue,we carried out in vitro induction culture experiment on the Bougainvillea bracts of 6 varieties of red,white,yellow and purple with 4 common colors;The changes of color parameters and pigment content of bracts were measured after induction culture,and the correlation was analyzed.The result showed that:(1)the red green phase value(a*)of bracts is the main color parameter that determines the color of bracts.Its color is mainly determined by beet pigment and flavonoid pigment,and betacyanins has the greatest influence.(2)Except that the content of flavonoids in the bracts of white varieties is higher than that of betacyanins,the content of beet pigment in the bracts of other varieties shows an upward trend,and the content of flavonoids pigment shows a downward trend.(3)The content of betalain is significantly positively correlated with the a*value and negatively correlated with the b*value of bracts,and the content of total flavonoids is significantly positively correlated with b*value and extremely significantly negatively correlated with a*value of bracts.(4)After being fed and cultured in vitro by DHM,the content and proportion of total flavonoids in the bracts of four varieties(‘Singapore White’,‘Baolao Cheng’,‘Chinese Beauty’,‘Ratana Yellow’)increased significantly,and which of total beet pigment in the bracts of all varieties decreased.The increase of total flavonoids content in the bracts of‘Singapore White’(+65.77%)is the largest,and its change of content proportion(26.91%)is also the largest among the six varieties.(5)Through the comprehensive analysis of grey correlation degree,the white variety‘Singapore White’has the highest correlation degree(0.7444)with the reference variety proposed by grey correlation degree analysis.Based on the results,Singapore White was the most appropriate transgene host for blue Bougainvillea ssp.The results of this study provide a reference for the directed breeding of blue Bougainvillea ssp..