Abstract:

【Objective】 The aim of this study was to elucidate the morphology and anatomical structures of moso bamboo (Phyllostachys edulis) culm neck. 【Method】 Morphological statistics, paraffin sections and sliding sections were used to analyze the morphology and anatomical structures.【Result】 The culm neck of mature bamboo shoots was about 3.22 cm long and had an average of 14 bud scales. The diameters in the top, middle and base of the culm neck were 1.2, 1.4, and 1.9 cm, respectively. The anatomical analysis showed that the moso bamboo culm neck had a solid structure with epidermis, hypodermis, cortex, vascular tissue and ground tissue distributed from outside to inside. There were seven layers of cells in the hypodermis, 25 layers of cells in the cortex, and approximately 672 vascular bundles on the cross section of the culm neck. The vascular bundles of the moso bamboo culm neck can be divided into six types based on the morphology. The fiber-cap closed vascular bundles with only a single metaxylem vessel were the main ones, which was significantly different from the moso bamboo culm with typically open vascular bundles. The parenchyma cells were arranged irregularly in the longitudinal direction, and there was no clear distinction between long and short cells. The longitudinal section showed that the lignification degree and the density of vascular bundles of the culm neck were the highest at the bottom, followed by the middle, and the lowest at the top. The anatomical observation of culm necks in the bamboo shoots at different growth stages showed that the number of bud scales, length, and diameter of the culm neck in the bamboo shoot at the late developmental stage were similar to those of the culm neck in the mature moso bamboo shoot. Further, the culm neck in the bamboo shoot at the early developmental stage had the same number of bud scales as the culm neck in the mature moso bamboo shoot. The length of the culm neck in the bamboo shoot at the early development stage was significantly shorter than that of the bamboo shoot at the middle and late development stages. 【Conclusion】 The anatomical structure of the moso bamboo culm neck was significantly different from that of the bamboo culm. The differentiation of the basic structures of the culm neck was completed in the bamboo shoot at the early developmental stage. There was a distinct elongation and growth process between the culm necks in the bamboo shoots during the early and later development stages.

Key words: Phyllostachys edulis, culm neck, vascular bundles, anatomy, morphology, development