Photosynthetic characteristics of Yulania denudata with variegated leaf based on anatomy

To reveal the causes of photosynthetic characteristics of Yulania denudata with variegated leaf, the green leaves, variegated leaves and yellow leaves of Y. denudata with variegated leaf were used as experimental materials. The anatomical structure and photosynthetic characteristics in three types of leaves were compared from the aspects of photosynthetic pigment content, leaf anatomical structure and light response curve. The results were as follows:(1)The yellow leaf spots of Y. denudata with variegated leaf were chlorophyll-type leaf spots formed by the decrease of chlorophyll content due to the abnormal structure of chloroplasts.(2)The structure of thylakoids in the yellow region of Y. denudata with variegated leaf was abnormal, and ATP synthesis was blocked, which hindered the progress of photosynthesis.(3)The anatomical structure showed that the palisade tissue of the green leaf was developed, the chloroplast integrity and pigment content were higher than those of the variegated leaf and the yellow leaf, and the net photosynthetic rate was higher.(4)There were significant differences in the maximum net photosynthetic rate and light saturation point between the green leaf and the variegated leaf, and the green leaf could withstand a wider range of bright light than the variegated leaf. This study further elucidates that the chloroplast structure of Y. denudata with variegated leaf affects its photosynthetic characteristics, and provides a reference for the breeding of excellent germplasm of Y. denudata with variegated leaf.