Arid Zone Research ›› 2024, Vol. 41 ›› Issue (7): 1177-1184.doi: 10.13866/j.azr.2024.07.09

• Plant Ecology • Previous Articles     Next Articles

Physiological, biochemical and morphological responses of Haloxylon ammodendron and Calligonum caput-medusae to drought stress

ZHANG Bin1,2(), LI Congjuan1(), Yi Guangping3, LIU Ran4   

  1. 1. National Technical Research Centre for Desert-Oasis Ecological Construction Engineering, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
    3. Altay Regional Forecasting and Control Center for Locusts and Rodents, Xinjiang Uygur Autonomous Region, Altay 836500, Xinjiang, China
    4. State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China
  • Received:2023-12-09 Revised:2024-04-18 Online:2024-07-15 Published:2024-08-01

Abstract:

Desertification and drought have emerged as global ecological issues, which pose significant difficulties for plant adaptability and survival. Consequently, it is crucial to investigate the adaptation mechanisms of plants to drought stress to preserve and grow sustainably artificial ecosystems in desert regions. This study examined the physiological, biochemical, and morphological responses of Haloxylon ammodendron and Calligonum caput-medusae in the Taklimakan Desert shelterbelt by employing two treatments: irrigation (20-day irrigation cycle) (CK) and drought (D). The findings demonstrated that under drought stress, the assimilatory branches of both plants were noticeably shorter in terms of morphological traits. The branches of both were also significantly thinner. Regarding physiological reactions, there were no notable distinctions between the two in terms of the photosynthetic gas exchange parameters and the leaf dry mass during drought stress. Additionally, the carboxylation processes, metabolic reaction rates, chlorophyll a, chlorophyll b, total chlorophyll, and photosynthetic enzyme contents of both did not exhibit any appreciable alterations under drought stress. However, both showed substantially reduced Fm and Fo values. The Fv/Fm values of H. ammodendron were noticeably greater, but those of C. caput-medusae did not change much. According to our study, H. ammodendron and C. caput-medusae were able to adapt to drought by reducing the assimilate-branch growth, excitation capacity, and photosynthetic pigment activity, thereby preserving photosynthetic capacity. The photochemical system of C. caput-medusae was less vulnerable to damage due to a stable chlorophyll concentration.

Key words: drought stress, photosynthetic fluorescence characteristics, morphological features, non-isohydric behavior