叶色退化的紫叶狼尾草生理变化特征

Characteristics of physiological changes of the leaf color degeneration of the Pennisetum setaceum ‘Rubrum’

为探索紫叶狼尾草叶色退化的生理特征,以自然光照(CK)、叶色退化(T_D)及长期遮阴(T_S)的3种紫叶狼尾草(Pennisetum setaceum‘Rubrum’)为试材,对其叶色参数及生理指标进行分析测定.结果表明:长期遮阴及退化的紫叶狼尾草叶色为黄绿级别,而对照为红色级别;3组紫叶狼尾草光合色素含量存在显著差异;长期遮阴及叶色退化的花色素苷和类黄酮含量显著高于对照组;对照组的类胡萝卜素和总叶绿素含量占比低于其他两组;3组紫叶狼尾草PAL和CHI活性差异显著且对照组最高;叶色参数L、a、b值与光合色素、花色素苷、类黄酮含量、PAL和CHI活性均存在显著或极显著相关.研究表明:对照组的叶色表现最佳,长期遮阴和叶色退化均为绿色叶,且遮阴和退化的色素占比相近,但光和色素含量差异显著;光合色素、花色素苷、类黄酮含量、PAL和CHI活性是影响紫叶狼尾草叶色的重要原因.

In order to explore the physiological characteristics of leaf color degradation for Pennisetum setaceum‘Rubrum',3 types of Pennisetum setaceum‘Rubrum',which were naturally grown(CK),degraded leaf color(TD)and long-term shade(TS)were studied.Leaf color parameters and physiological indexes were analyzed.The results showed that leaf color of TS and TD P.setaceum‘Rubrum'was yellow-green,while the control was red.The photosynthetic pigment content of 3 groups varied significantly.Contents of glucosinolates and flavonoids,the percentages of carotenoids and total chlorophyll content were significantly higher in TS and TD P.setaceum‘Rubrum'than those of the control group.PAL and CHI activities varied significantly among 3 groups and higher than CK.Leaf color parameters of L,a and b values were significantly or extremely significantly correlated with photosynthetic pigment,anthocyanin,flavonoid content,PAL and CHI activity.To summarize,the leaf color of the control group was the best.TS and TD groups were all green leaves,and the ratio of shaded and degraded pigments was similar,but the difference of light and pigment content was significant.Photosynthetic pigments,anthocyanins,flavonoids,PAL and CHI activity synthetically determined leaf color.