Study on the variations in growth and photosynthetic characteristics of Paspalum notatum Flugge in response to water stress in arid-hot valley regions
2025
Yuxiao He | Siyu He | Lu Yang | Yufei Liu
A pot-controlled watering approach was employed to reveal the effect of soil water stress on photosynthetic physiology of Paspalum notatum Flugge under special climatic conditions in arid-hot valley region. Four treatments were set up: control (CK), low stress (LS), moderate stress (MS), and high stress (HS). Physiological measurements were taken to assess indices such as absolute plant height, canopy area, leaf area, leaf water content, and leaf water potential. Additionally, photosynthetic parameters were measured, including net photosynthetic rate, intercellular CO2 concentration, stomatal conductance and chlorophyll fluorescence. The results indicate that under water stress, as the duration of stress increases, the growth of Paspalum notatum Flugge was inhibited, the water available in the body of Paspalum notatum Flugge gradually decreased. Photosynthesis was inhibited and PS II reaction center was disrupted to some extent. To improve water retention, Paspalum notatum Flugge initiated self-protective mechanisms, diminishing leaf water potential and enhancing ability to absorb water from the soil. In the meantime, Paspalum notatum Flugge adjusted to adversity by reducing the stomatal aperture to inhibit water loss, lowering Tr, and increasing WUE. The experiment showed that after rehydration, damaged photosynthetic apparatus of Paspalum notatum Flugge retained a certain self-recovery capability. This phenomenon suggests the reversible deactivation of the photosynthetic apparatus in response to water stress.
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