彩叶桂叶色变化及生理特征分析

Color change and physiological characteristics in Osmanthus fragrans Colour Group

【目的】探讨彩叶桂Osmanthusfragrans Colour Group在生长过程中叶色变化及相关生理特征,为彩叶桂的品种分类、筛选和改良提供理论依据。【方法】选取29份彩叶桂种质材料,运用量化标准并结合聚类分析方法对其进行分类。同时,从中选择2个代表性品系(‘罗彩3号’‘Luocai 3’和‘罗彩28号’‘Luocai 28’)进行色素分布观察、组分定性、质量分数测定以及生理指标测定。【结果】基于叶片变色30%的叶色参数进行聚类分析,将彩叶桂品系分为两大类共3个色系,即红棕色系(第Ⅰ类第1亚类)、橙棕色系(第Ⅰ类第2亚类)和紫粉色系(第Ⅱ类)。解剖结构显示:花青素主要分布在幼嫩叶片的上下表皮细胞中,并随着叶片生长逐渐减退。同时,花青素质量分数逐渐下降,叶绿素质量分数持续上升,而类胡萝卜素质量分数虽逐渐上升但变化不显著。在叶片生长过程中,2个品系可溶性蛋白和可溶性糖质量分数的变化无明显规律,但在叶片变色为0时相对较高;过氧化物酶(POD)活性不断增加,但‘罗彩3号’在每个时期均高于‘罗彩28号’;叶片pH无显著变化且始终处于酸性范围。【结论】基于叶片变色30%的叶色参数可对彩叶桂进行色系划分。彩叶桂叶色变化主要受花青素质量分数减少和叶绿素质量分数增加的影响,而POD在其中发挥了重要作用。红棕色系和橙棕色系之间的区别在于花青素和类胡萝卜素的质量分数及其比值。图7表1参29.

[Objective]This study,with an investigation of the classification of Osmanthus fragrans Colour Group and the changes of leaf color and related physiological characteristics during its growth,is aimed to provide theoretical basis for the classification,selection and improvement of Colour Group.[Method]With a total of 29 germplasm materials of Colour Group selected and classified by quantitative criteria and cluster analysis,two representative lines(‘Luocai 3’and‘Luocai 28’)were selected to observe the pigment distribution,component qualitative analysis,content determination and physiological index determination.[Result]Based on the cluster analysis at the stage of 30%leaf discoloration(S2),the cultivars were divided into two categories and three color series,namely the reddish brown series(the first subclass of ClassⅠ),the orange brown series(the second subclass of Class I),and the purple pink series(the second subclass of ClassⅡ).The anatomical structures of the two strains showed that anthocyanins were mainly distributed in the upper and lower epidermal cells of young leaves,and gradually decrease with leaf growth with the content of anthocyanins gradually decreasing,the content of chlorophyll continuing to rise and the content of carotenoids gradually increasing insignificantly.During the growth process of leaves,there was no significant pattern in the changes of soluble protein and soluble sugar content between the two,but they were relatively high in the S1 stage.The POD activity continued to increase,with‘Luocai 3’being higher than‘Luocai 28’at each stage and the pH value of the leaves showed no significant change and remained within the acidic range.[Conclusion]Based on the leaf color parameters of the S2 period,a detailed color scheme division can be carried out for Colour Group.The color change of Colour Group leaves is mainly affected by the decrease in anthocyanin content and the increase in chlorophyll content,in which POD plays an important role.The difference between the reddish brown and orange brown series lies in the content and ratio of anthocyanins and carotenoids.[Ch,7 fig.1 tab.29 ref.]