关键词: 紫叶象草, 紫叶狼尾草, 白茅, 叶色参数, Lab模型, 叶绿素

Abstract: Leaf color is one of the most important ornamental features of ornamental grasses. In this paper,Pennisetum purpureum ‘Red’,Pennisetum setaceum ‘Rubrum’ and Imperata cylindrica with colored leaves in winter were as objects to analyze their leaf color characteristics and the relationship between leaf color and chlorophyll using the Lab model so that it could provide a reference for the key indicators of ornamental grass breeding and color quantification. The results showed that the L value of Pennisetum purpureum ‘Red’ was the lowest and the a value was stable. The a value of Pennisetum setaceum ‘Rubrum’ was the biggest,and the L and b values of Imperata cylindrica were the biggest. On the same leaf,the a value of the base of Pennisetum purpureum ‘Red’ was the biggest and had significantly different from the middle and the top. The L value of the top of Pennisetum setaceum ‘Rubrum’ was the biggest and had significantly different with the other two parts. The L and b value of the base of Imperata cylindrica were bigger. In the same plant,the a value of the top of Pennisetum purpureum ‘Red’ was the biggest and the lower b value was higher. The a value of the top and bottom of Pennisetum setaceum ‘Rubrum’ was bigger. The smallest a value of Imperata cylindrica was the highest. The leaf color parameter had significant or extremely significant negative correlation with chlorophyll content. According to the analysis,the leaf color of each ornamental grass was different,and chlorophyll was one of the main factors affecting the color of the ornamental grass. The leaf color characteristics should be fully considered when plants are planted.

Key words: Pennisetum purpureum ‘Red’, Pennisetum setaceum ‘Rubrum’, Imperata cylindrica, leaf color parameters, Lab model, chlorophyll