关键词: 金叶女贞, 叶结构, 叶绿素, 冠层位置

Abstract: Ligustrum×vicaryi is widely used as a landscaping shrub for horticultural ornamentation. It possesses leaves with two contrasting colors in the upper and lower positions. The upper leaves are golden while the lower leaves tend to be green during the whole growth season due to their positions. Light intensity may play a key role in generating these two types of leaves. In this paper, leaf anatomy in the upper golden leaves and lower green leaves was investigated. The results showed that light intensity did not affect the upper epidermis significantly; but under low light, the lower epidermis cells were smaller, and the stomatal density decreased. Mesophyll tissues in the lower leaves were thinner than those in the upper leaves, and the size of mesophyll cells increased and arranged loosely under low light. Thylakoids arranged more closely and the number of chloroplasts per leaf volume decreased under low light than those under high light. Low position promoted the accumulation of photosynthetic pigments and made leaves dark green. The effects of canopy position on leaf anatomy in the golden-leaf shrubs were similar to other plants, but the content of photosynthetic pigments varied more largely than other plants. Taken together, golden-leaf privet could be an ideal plant to study leaf morphology, structures, development, physiology and biochemistry responses to canopy position.

Key words: Ligustrum×, vicaryi, structure of leaf, chlorophyll, canopy position