Arid Zone Research ›› 2024, Vol. 41 ›› Issue (2): 272-283.doi: 10.13866/j.azr.2024.02.10

• Plant Ecology • Previous Articles     Next Articles

Effects of soil microbial films on the photosynthesis and fluorescence characteristics of psammophyte seedlings

WU Weiting1,2,3,4(), WANG Yu1,2,3,4, GAO Guanglei1,2,3,4,5(), ZHANG Ying1,2,3,4, DING Guodong1,2,3,4, CAO Hongyu1,2,3,4   

  1. 1. School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
    2. Yanchi Ecology Research Station of the Mu Us Desert, Yanchi 751500, Ningxia, China
    3. Engineering Research Center of Forestry Ecological Engineering, Beijing 100083, China
    4. Key Laboratory of State Forestry and Grassland Administration on Soil and Water Conservation, Beijing 100083, China
    5. State Key Laboratory of Efficient Production of Forest Resources, Beijing 100083, China
  • Received:2023-05-23 Revised:2023-10-20 Online:2024-02-15 Published:2024-03-11

Abstract:

This study investigated the impact of soil microbial film sand fixation on the photosynthetic and fluorescence characteristics of seedlings from two psammophyte species, Ammopiptanthus mongolicus and Astragalus laxmannii. A pot experiment was conducted utilizing different application methods (spray, mix) and application amounts (0, 1, 3, 5, 7, and 10 g·kg-1). After soil microbial biofilm formation, the characteristics of plant gas exchange and chlorophyll fluorescence were analyzed. The results showed that: (1) An application of bacteria exceeding 3 g·kg-1 notably increased the hardness and thickness of the consolidated layer, alongside higher soil urease and sucrase activities compared to the control group (P < 0.05). (2) The net photosynthetic rate of Astragalus laxmannii in 3-7 g·kg-1 treatment was significantly higher than that of the control (P < 0.05). Additionally, its transpiration rate, net photosynthetic rate, and intercellular CO2 concentration surpassed those of Ammopiptanthus mongolicus (P < 0.05). (3) Astragalus laxmannii treated with over 5 g·kg-1 displayed significantly higher Fv/Fm values compared to the control group (P < 0.05). Except for the 3 g·kg-1 treatment, Ammopiptanthus mongolicus exhibited higher Fv/Fm and QP values than Astragalus laxmannii. (4) Soil properties, photosynthetic gas exchange, and chlorophyll fluorescence were partially mediated models. Changes in soil characteristics can directly affect the chlorophyll fluorescence characteristics of Ammopiptanthus mongolicus and Astragalus laxmannii. The soil microbial film increased consolidation layer hardness and thickness by 3.84% and 152.85%, respectively, and enhanced catalase, urease, and sucrase activities by 93.37%, 170.68%, and 256.03%, respectively. This improvement in soil quality and leaf stomatal conductance enhanced photosynthetic efficiency and capacity in both plants. The net photosynthetic rate and Fv/Fm increased by 28.48% and 0.84%, respectively.

Key words: soil microbial films, psammophyte, photosynthesis, chlorophyll fluorescence