Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (12): 1365-1379.DOI: 10.17521/cjpe.2021.0164

• Research Articles • Previous Articles     Next Articles

Diurnal transpiration of bamboo culm and sheath and their potential effects on water transport during the bamboo shoot stage

LI Tang-Ji1, WANG Mao-Lin1,2, CAO Ying1,*(), XU Gang1, YANG Qi-Qi1, REN Si-Yuan1, HU Shang-Lian1,2,*()   

  1. 1School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan 621010, China
    2Engineering Research Center for Biomass Resource Utilization and Modification of Sichuan Province, Mianyang, Sichuan 621010, China
  • Received:2021-04-28 Accepted:2021-07-15 Online:2021-12-20 Published:2021-09-18
  • Contact: CAO Ying,HU Shang-Lian
  • Supported by:
    14th Five-Year Key Project of Sichuan Province(20zs2172);Key Research and Development Projects of Sichuan Province(2019YFN0005);Sichuan’s Training Program of Innovation and Enterpreneurship for Undergraduate(19xcy056)


Aims Water transport is of critical impact on the growth of bamboo shoots. The mechanism of diurnal water transpiration by bamboo shoots, and its effect on water transport was not yet fully comprehended. The objectives of this study include: 1) to characterize the structure of bamboo shoots that influence transpiration; 2) to examine the ability of the structure in transporting water; 3) to examine the structure of culm sheath for understanding water transfer in bamboo shoots.

Methods Bambusa emeiensisshoots of different elongation stages were used to characterize the stomata, for examining stomatal conductance (Gs), transpiration rate (Tr) and other physiological features of culm sheaths and shoot body. Water transport rate of shoots in vitro was also examined.

Important findings The results showed that: 1) there are a large number of small and concave stomata on the surface of culm sheath and bamboo shoot of different development states, their net photosynthetic rate (Pn), chlorophyll (Chl) a, and Chl b content were extremely low, but Gs and Tr were significantly higher than that of the mature leaves. These indicated that culm sheath and bamboo shoot play important roles in transpiration and respiration. 2) The tracing results of safranine solution in vitro showed that shoots of higher daily elongation rate had stronger transpiration, and were higher rising rate of safranine solution in the bamboo shoots. When culm sheaths of bamboo shoots were separated, the safranine solution could still diffused and transported in the shoot bodies, indicating that the shoot body itself carried some transpiration. However, compared with the intact bamboo shoots wrapped by culm sheaths, the rising safranine solution decreased significantly after the culm sheaths were separated, indicating that the culm sheath could make important contribution for the water transportation. 3) Anatomical analysis showed that some longitudinal vascular bundles of the internodes formed a plate-like structure (PLS) at the bamboo nodes, and the ends of PLS gradually bent and stretched into the bamboo sheath. The PLS may be an important structural basis for water transport of bamboo sheath.

Key words: diurnal transpiration, water transport, stomata, culm sheath, bamboo shoot