摘要
The effects of major veins severing on morphological and physiological features of sweetgum （Liquidambar styraciflua L.） leaves were investigated by observing leaf color change and measuring leaf temperature, green/luminance （G/L） value of half-lobes, leaf stomata conductance, and water content in Yamaguchi University, Japan. The palmately veined leaves of sweetgum （Liquidambar styraciflua L.） were found more sensitive to the major vein severing than that of other species Major veins severing resulted in serious water stresses, as indicated by the persistent reddening and/or advanced reddening of local leaf, lower leaf stomatal conductance, and higher leaf temperature, etc. Severed leaf can be clearly divided into non-severed area, transitional area, and stressed area, which the three areas have different colours and temperature. The major vein barrier can also be seen clearly. The persistent reddening and advanced reddening seem consistent with the phenomenon of red crown top of some sweetgum trees and may have similar mechanism.
通过观察叶色变化和测定叶片温度、G/L值、气孔导度、水分含量等,调查了日本山口大学北美枫香叶叶脉切断对其形态、生理学的作用。与其他形状的叶片比较,具有掌状叶脉的北美枫香叶片对主脉切断更加敏感。主脉切断造成严重的水分胁迫,表现出叶色永久变红或局部早红、低气孔导度和高叶温等。主脉切断的叶片可以分成未受胁迫区、过渡区和胁迫区,这三部分分别呈现出不同的颜色和叶温。主脉防御界线清晰可见。主脉切断形成的永久变红或早红似乎与一些北美枫香树冠红顶现象相近,可能具有相似的机制。
