Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Nanjing Forestry University, Nanjing 210037, China.
Bamboo Research Institute, Nanjing Forestry University, Nanjing 210037, China.
Ying Yong Sheng Tai Xue Bao. 2023 Jan;34(1):83-91. doi: 10.13287/j.1001-9332.202301.040.
Bamboo nodes play a key role in the hollow structure and the rapid growth of bamboo culm. Studying on the anatomical structure of bamboo is helpful to understand its growth mechanism. Taking the noninvasive, high-resolution and accurate technical advantages of magnetic resonance imaging (MRI), we conducted cross-sectional high-resolution MRI scanning on the tip of young Moso bamboo culm (removed shoot sheath) and extracted the gray value of the MRIs by using MATLAB software to explore the differences of water distribution in nodes, proximal nodes, and internodes. The results showed that numerous vascular bundles were repeatedly twisted and rotated horizontally at the nodal diaphragms and inner wall near the nodal diaphragms of the young bamboo, forming an intricate and highly connected network. The structure protected important tissues from mechanical stress by allocating axial loads, and enabled to laterally transport water and nutrients, which was an important basis for the rapid growth of Moso bamboo in relatively short term. The signal value (also known as brightness value) of MRIs indicated that water content of vascular bundles in young bamboo culm was much higher than that of surrounding parenchyma tissues. The mean value and standard deviation of water content between pixels of internodes were significantly higher than that of nodes, and the values of that in the proximal nodes were intermediate. The development of MRI would play a significant role in the studies of bamboo anatomy, physiology, and biochemistry.
竹节在竹子的中空结构和快速生长中起着关键作用。研究竹子的解剖结构有助于了解其生长机制。磁共振成像（MRI）具有非侵入性、高分辨率和精确的技术优势，我们对幼竹（去掉叶鞘）的梢端进行了横截面高分辨率 MRI 扫描，并使用 MATLAB 软件提取 MRI 的灰度值，以探讨节点、近节和节间中水分分布的差异。结果表明，大量的维管束在节点隔膜和节点隔膜附近的内墙上反复水平扭曲和旋转，形成了一个错综复杂、高度连接的网络。该结构通过分配轴向载荷来保护重要组织免受机械应力，并且能够横向运输水和营养物质，这是毛竹在相对较短的时间内快速生长的重要基础。MRI 的信号值（也称为亮度值）表明，幼竹茎维管束的含水量远高于周围的薄壁组织。节间像素之间的含水量的平均值和标准差明显高于节点，而近端节点的值则介于两者之间。MRI 的发展将在竹子解剖学、生理学和生物化学的研究中发挥重要作用。
