Abstract:

Objective: This study aims to investigate the structural differences of the leaves of the main Bambusa and Phyllostachys species in Nanjing, to understand the three-dimensional images of the internal anatomical structures of the leaves of those bamboo plants, and construct the three-dimensional morphological structure maps of the leaves of 52 bamboo species. Method: Six species in Bambusa and 46 species in Phyllostachys collected from Nanjing area were used as test materials, and three-dimensional sections of the leaves were prepared by paraffin section method. The anatomical structures of each section of the leaves of 52 bamboo species were observed and measured by an optical microscope imaging system, and the three-dimensional structure diagram of the leaves of 52 bamboo species were reconstructed by Photoshop. Result: 1) The results showed that the thickness of leaf cuticle and the number of lower epidermal papillae were the markers to distinguish Bambusa from Phyllostachys. The leaf thickness and cuticle thickness of Phyllostachys were significantly greater than those of Bambusa, and the number of lower epidermal papillae was significantly greater than that of Bambusa. 2) Usually, 2 to 6 vesicular cells made up a group, and the morphology and number of vesicular cells were not fixed between species, and there were obvious differences in the number of vesicular cells in a group between genera. The vesicular cells in each group in the genus Bambusa were arranged in a fan-shaped (obtuse) pattern, while those in the genus Phyllostachys were arranged at a right angle or an acute angle pattern. 3) Each vascular system consisted of main vein, parallel lateral vein, secondary parallel lateral vein and minor transverse vein. The gap of spindle cells on both sides of the bundle of Bambusa was developed, while the spindle cells and gaps on both sides of the bundle of Phyllostachys were generally undeveloped and discontinuous. 4) There were 3–4 mesophyll cell layers between the parallel lateral veins of Bambusa, while there were 4–6 mesophyll cell layers between the parallel lateral veins of Phyllostachys. The mesophyll cells of Phyllostachys were more compact than those of Bambusa. Conclusion: The leaf thickness and cuticle thickness of Phyllostachys are greater than those of Bambusa, and the finger-like arm cells and plum cells of Phyllostachys are denser than those of Bambusa, while the cellular space of Phyllostachys is smaller than that of Bambusa, and the number of papillae in the lower epidermis of Phyllostachys is obviously greater than that of Bambusa. Therefore, the cold resistance of Phyllostachys may be stronger than that of Bambusa. This study is an important supplement to establish and improve the observation method of bamboo leaf structure, and provides a basis and reference for the classification of bamboo with the characteristics of plant anatomy and morphology.

Key words: bamboo leaves, Bambusa, Phyllostachys, anatomical characteristics, three-dimensional structure