scholarly journals Drought exerts a greater influence than growth temperature on the temperature response of leaf day respiration in wheat (Triticum aestivum)

2021 ◽  
Author(s):  
Liang Fang ◽  
Xinyou Yin ◽  
Peter E. L. van der Putten ◽  
Pierre Martre ◽  
Paul C. Struik
Keyword(s):  
Climate Change ◽  
Triticum Aestivum ◽  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Growth Temperature ◽  
Temperature Response ◽  
Popular Method ◽  
Water Regimes ◽  
Fluorescence Measurements ◽  
Fitting Method

We assessed how the temperature response of leaf day respiration (Rd) in wheat responded to contrasting water regimes and growth temperatures. In Experiment 1, well-watered and drought-stressed conditions were imposed on two genotypes; in Experiment 2, the two water regimes combined with high (HT), medium (MT) and low (LT) growth temperatures were imposed on one of the genotypes. Rd was estimated from simultaneous gas exchange and chlorophyll fluorescence measurements at six leaf temperatures (Tleaf) for each treatment, using the Yin method for non-photorespiratory conditions and the non-rectangular hyperbolic fitting method for photorespiratory conditions. The two genotypes responded similarly to growth and measurement conditions. Estimates of Rd for non-photorespiratory conditions were generally higher than those for photorespiratory conditions but their responses to Tleaf were similar. Under well-watered conditions, Rd and its sensitivity to Tleaf slightly acclimated to LT but did not acclimate to HT. Temperature sensitivities of Rd were considerably suppressed by drought, and the suppression varied among growth temperatures. Thus, it is necessary to quantify interactions between drought and growth temperature for reliably modelling Rd under climate change. Our study also demonstrated that the Kok method, a currently popular method for estimating Rd, underestimated Rd significantly and should be abandoned.

Seedling mortality during biphasic drought in sandy Mediterranean soils

2014 ◽  
Vol 41 (12) ◽  
pp. 1239 ◽  
Author(s):  
Stephen M. Benigno ◽  
Kingsley W. Dixon ◽  
Jason C. Stevens
Keyword(s):  
Climate Change ◽  
Gas Exchange ◽  
Water Potential ◽  
Soil Water ◽  
Future Climate Change ◽  
Individual Species ◽  
Seedling Mortality ◽  
Deep Soil ◽  
Xylem Water Potential ◽  
Fluorescence Measurements

Climate change is increasing the frequency and intensity of drought, and seedling response to a recurrent pattern of drought stress is necessary to understand vegetation establishment patterns in particularly for ecological restoration and conservation projects. A controlled environment study investigated seedling physiological response of framework Mediterranean tree species to simulated successive droughts. Six-month-old seedlings were grown in 1.0 m tall pots to emulate deep soil profiles and subjected to a well watered treatment and a drought treatment consisting of an initial 60 day drought (water withholding), followed by 120 days of re-watering and a subsequent 60 day drought. Soil water access, soil water content, maximum root depth and xylem water potential were assessed through successive harvests. To assess seedling response to multiple droughts, gas-exchange and chlorophyll fluorescence measurements were taken every 15 days after each drought, and multiple times throughout re-watering. No seedling mortality was observed during the initial drought, whereas 100% mortality of all species occurred within 48 days of the second drought. Seedling gas exchange and water potential decreased with decreasing water availability but was dependent on the isohydric or anisohydric behaviour of individual species. An absence of sustained photoprotection during the second drought phase heightened photodamage to foliar tissues resulting in a more rapid decrease of gs and leaf water potential. Therefore, biphasic drought proved detrimental to seedling establishment by reducing physiological resilience, highlighting the severity of future climate change predictions towards the regeneration capacity of Mediterranean ecosystems.

Laser-Induced Chlorophyll Fluorescence Measurements for Detecting the Nitrogen Status of Wheat (Triticum aestivum L.) Canopies

2005 ◽  
Vol 6 (2) ◽  
pp. 143-156 ◽  
Author(s):  
J. Sch�chtl ◽  
G. Huber ◽  
F.-X. Maidl ◽  
E. Sticksel ◽  
J. Schulz ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Chlorophyll Fluorescence ◽  
Triticum Aestivum L ◽  
Nitrogen Status ◽  
Fluorescence Measurements
Sign in / Sign up

Export Citation Format

Share Document