Chin J Plant Ecol ›› 2023, Vol. 47 ›› Issue (8): 1159-1170.DOI: 10.17521/cjpe.2022.0173

Special Issue: 全球变化与生态系统 光合作用

• Research Articles • Previous Articles     Next Articles

Sexual divergence of Populus deltoides seedlings growth and ecophysiological response to drought and rewatering

SHI Meng-Jiao, LI Bin, YI Li-Ta, LIU Mei-Hua*()   

  1. College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300, China
  • Received:2022-04-29 Accepted:2022-09-28 Online:2023-08-20 Published:2022-09-28
  • Contact: *LIU Mei-Hua(
  • Supported by:
    Natural Science Foundation of Zhejiang Province(LY19C160005)


Aims Global climate change has aggravated the effects of drought which is one of the major factors restricting the sustainable development of agriculture and forestry. It is important to study the growth performance and the changes of physiological mechanism of dioecious plants during drought and rewatering process, which could help to understand the difference of adaptability and stress tolerance to the unfavorable environment in dioecious plants. And this paper also provides a theoretical basis for the selection of tree species for afforestation in the context of global climate change.

Methods Male and female cuttings of Populus deltoides were planted in the pots in a greenhouse, and were treated by drought stress and rewatering. The growth, leaf water parameters, and photosynthetic parameters were measured to analyze the physiological adaptability and stress tolerance of males and females under drought-rewatering conditions.

Important findings Drought stress showed negative effects on plant growth by reducing the growth of plant height and basal diameter, with decreased relative water content, water potential, net photosynthetic rate, stomatal conductance, transpiration rate, photosynthetic electron yield, photochemical quenching coefficient and electron transfer rate of leaves of males and females. There were no significant sexual differences in all parameters between males and females under sufficient water supply. Under drought stress, the growth of male plants was better than that of females, with higher growth rate of plant height and more root biomass accumulation in males. Drought resulted in the decrease of the maximum photochemical efficiency and the potential activity of photosystem II (PSII), and the increase of the intercellular CO2 concentration of females. PSII of male plants was less damaged under drought conditions, and the photosynthetic reaction center still maintained a high light-harvesting efficiency. Meanwhile, alternating oxidase (AOX) activity was significantly increased in roots and leaves of male seedlings, which could alleviate the effect of photoinhibition. All indexes recovered after 30 days of rewatering. However, the growth rate of plant height and ground diameter, and net photosynthetic rate of males and females under drought stress were significantly lower than those of the control group without drought stress. The results showed that the growth of male and female seedlings of P. deltoides was inhibited by drought stress, and the females were more likely affected by water deficit. Water stress induced a series of adaptive physiological effects in males, including decreased leaf relative water content, decreased photosynthetic and chlorophyll fluorescence parameters, and increased activity of alternating oxidase. Therefore, males had a more effective protective mechanism than females, which was also conducive to the recovery of various functions after rewatering.

Key words: drought, rewatering, dioecious, growth physiology, Populus deltoides