Ananas comosus var.bracteatus is an important ornamental plant because of its green/white chimeric leaves.The accumulation of anthocyanin makes the leaf turn to red especially in the marginal part.However,the red fade...Ananas comosus var.bracteatus is an important ornamental plant because of its green/white chimeric leaves.The accumulation of anthocyanin makes the leaf turn to red especially in the marginal part.However,the red fades away in summer and winter.Light intensity is one of the most important factors affecting leaf color along the seasons.In order to understand the effects of light intensity on the growth and coloration of the chimeric leaves,Ananas comosus var.bracteatus was grown under full sunlight,50%shade and 75%shade for 75 days to evaluate the concentration of pigments,the color parameters(values L^(*),a^(*),b^(*))and the morpho-anatomical variations of chimeric leaves.The results showed that a high irradiance was beneficial to keep the chimeric leaves red.However,prolonged exposure to high irradiance caused a damage,some of the leaves wrinkled and even burned.Shading instead decreased the concentration of anthocyanin and increased the concentration of chlorophyll,especially in the white marginal part of the leaves.Numerous chloroplasts were observed in the mesophyll cells of the white marginal part of the chimeric leaves under shading for 75 days.The increase in chlorophyll concentration resulted in a better growth of plants.In order to balance the growth and coloration of the leaves,approximately 50%shade is suggested to be the optimum light irradiance condition for Ananas comosus var.bracteatus in summer.展开更多
基金This work was funded by the National Natural Science Foundation of China(Grant Nos.31971704,31770743).
文摘Ananas comosus var.bracteatus is an important ornamental plant because of its green/white chimeric leaves.The accumulation of anthocyanin makes the leaf turn to red especially in the marginal part.However,the red fades away in summer and winter.Light intensity is one of the most important factors affecting leaf color along the seasons.In order to understand the effects of light intensity on the growth and coloration of the chimeric leaves,Ananas comosus var.bracteatus was grown under full sunlight,50%shade and 75%shade for 75 days to evaluate the concentration of pigments,the color parameters(values L^(*),a^(*),b^(*))and the morpho-anatomical variations of chimeric leaves.The results showed that a high irradiance was beneficial to keep the chimeric leaves red.However,prolonged exposure to high irradiance caused a damage,some of the leaves wrinkled and even burned.Shading instead decreased the concentration of anthocyanin and increased the concentration of chlorophyll,especially in the white marginal part of the leaves.Numerous chloroplasts were observed in the mesophyll cells of the white marginal part of the chimeric leaves under shading for 75 days.The increase in chlorophyll concentration resulted in a better growth of plants.In order to balance the growth and coloration of the leaves,approximately 50%shade is suggested to be the optimum light irradiance condition for Ananas comosus var.bracteatus in summer.
