植物生态学报 ›› 2023, Vol. 47 ›› Issue (8): 1159-1170.DOI: 10.17521/cjpe.2022.0173

所属专题: 光合作用

• 研究论文 • 上一篇    下一篇

美洲黑杨幼苗生长和生理生态指标对干旱-复水响应的性别差异

施梦娇, 李斌, 伊力塔, 刘美华*()   

  1. 浙江农林大学林业与生物技术学院, 杭州 311300
  • 收稿日期:2022-04-29 接受日期:2022-09-28 出版日期:2023-08-20 发布日期:2022-09-28
  • 通讯作者: *刘美华(mhliu@zafu.edu.cn)
  • 基金资助:
    浙江省自然科学基金(LY19C160005)

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(mhliu@zafu.edu.cn)
  • Supported by:
    Natural Science Foundation of Zhejiang Province(LY19C160005)

摘要:

研究雌雄异株植物在干旱-复水过程中的生长表现和生理机制变化有助于了解不同性别植物对环境的适应以及抗逆能力差异, 可为全球气候变化背景下造林树种的选择提供理论依据。该研究以美洲黑杨(Populus deltoides)为研究对象, 采用盆栽控水实验, 通过测定干旱-复水条件下幼苗的生长、叶片水分参数、光合参数等指标, 分析雌雄植株对不同水分处理的生理响应差异。结果显示: 干旱对雌雄植株生长均产生不利影响, 植株株高和地径生长减缓, 叶片的相对含水量、水势、净光合速率、气孔导度、蒸腾速率、光合电子产量、光化学猝灭系数以及电子传递速率均显著降低。干旱胁迫下, 雄株的生长情况优于雌株, 表现为雄株有更高的株高生长速率、地下生物量分配和水分利用效率。干旱胁迫下, 雌株最大光化学效率与光系统II (PSII)的潜在活性显著降低, 胞间CO2浓度显著增加; 雄株PSII受损伤较小, 但根和叶的线粒体交替氧化酶活性显著升高。复水30天后, 植株的各指标均有不同程度的恢复, 但雌雄株的株高、地径增长率和净光合速率等显著低于未经过干旱胁迫的对照组, 且不存在性别差异。干旱胁迫下, 美洲黑杨雌雄株幼苗的生长均受到不同程度的抑制, 雌株较雄株受影响更大。雄株通过降低叶片相对含水量、光合速率和叶绿素荧光参数, 增加交替氧化酶活性等一系列生理响应来提高植株干旱适应性。因此, 雄株比雌株具有更有效的保护机制, 有利于复水后各生理活动的恢复。

关键词: 干旱, 复水, 雌雄异株, 生长生理, 美洲黑杨

Abstract:

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