2种刺柏属彩色树叶色参数与色素变化

  目的  研究刺柏属Juniperus彩色树叶色参数与色素变化规律。  方法  以欧洲刺柏‘金叶疏枝’Juniperus communis ‘Gold Cone’ (JC)和鹿角桧‘金叶’Juniperus×media ‘Pfitzeriana Aurea’ (JM) 2年生扦插苗为对象，测定不同季节叶色参数(L*、a*、b*)、光合色素(叶绿素a、叶绿素b、类胡萝卜素)质量分数和花色素苷相对含量，并进行相关分析，建立叶色参数和色素含量的回归方程。  结果  ①不同季节欧洲刺柏‘金叶疏枝’和鹿角桧‘金叶’的叶色参数变化趋势不同。‘金叶疏枝’的L*、b*值变化趋势相同，始终为正值，a*值秋冬季显著升高，由负变正；‘金叶’的L*值春夏显著上升，a*值波动幅度不明显，色相始终偏绿，b*值春夏显著上升，秋冬季无波动，色相始终偏黄；春夏秋季‘金叶疏枝’的L*、b*值显著高于‘金叶’。②‘金叶疏枝’的花色素苷相对含量与L*、b*值呈极显著负相关，与a*值呈极显著正相关；‘金叶’的光合色素与b*值呈极显著负相关。③逐步回归结果表明:a*值与b*值可以准确预估‘金叶疏枝’花色素苷相对含量的年变化和秋季变化，b*值和L*值可以准确预估‘金叶’光合色素质量分数的年变化和夏季色素变化。  结论  2种刺柏属彩色树的叶色参数与色素含量关系显著相关，不同树种不同时期存在差异；‘金叶疏枝’叶色观赏性整体好于‘金叶’。建立的叶色参数与色素含量回归方程，可以实现以叶色参数精确预估叶片色素含量。图2表4参32

Change of color parameters and pigment content of colored leaves of two Juniperus cultivars

[Objective]Aimed at a study of the color parameters and the pigment content of Juniperus colored leaves.[Method]Two-year-old cutting seedlings of Juniperus communis‘Gold Cone’(JC)and Juniperus×media‘Pfitzeriana Aurea’(JM)were used to determine the leaf color parameters(L*,a*,b*),relative content of photosynthetic pigments(chlorophyll a,chlorophyll b,carotenoids)and anthocyanins,with a correlation analysis conducted to establish the regression equation of leaf color parameters and pigment content.[Result](1)The changing trends of leaf color parameters of JC and JM are different in different seasons:the L*and b*values of JC have the same changing trend and are always positive,and the a*value increases significantly in autumn and winter from negative to positive.The L*value of JM rises significantly in spring and summer,with the fluctuation of a*value unobvious,the hue always greenish whereas the b*value rises significantly in spring and summer with no fluctuation in autumn and winter,and the hue always yellow.The L*and b*values of JC in spring,summer and autumn are significantly higher than those of JM.(2)The relative content of anthocyanin in JC has a very significant negative correlation with L*and b*values,and a very significant positive correlation with a*value while JM photosynthetic pigments have a very significant negative correlation with b*value.(3)The results of the stepwise regression equation show that the a*and b*values can accurately predict the annual and autumn changes of the anthocyanin content of JC,and the b*and L*values can accurately predict the annual and summer changes in the photosynthetic pigment content of JM pigment changes.[Conclusion]The relationship between leaf color parameters and pigment content of the two color trees of Juniper genus is significantly correlated with differences in different tree species during in different periods and the leaf color of JC generally better than that of JM.The established regression equation of leaf color parameters and pigment content can help make an accurate estimation of leaf pigment content based on leaf color parameters.