Stomatal conductance bears no correlation with transpiration rate in wheat during their diurnal variation under high air humidity

Abstract

A good understanding of the response of photosynthesis rate (PN) and transpiration rate (Tr) to stomatal alteration during the diurnal variations is important to cumulative photosynthetic production and water loss of crops. Six wheat genotypes were studied for 2 years with pot cultivation in rain-shelter. Among different genotypes, stomatal conductance (gs) was significantly correlated with both PN and Tr. But for each genotype, though gs was significantly correlated with PN regardless of relative air humidity (RH) status and it was also significantly correlated with Tr under lower RH (LRH, 15.4%) and moderate RH (MRH, 28.3%), it was not correlated with Tr under higher RH (HRH, 36.7%) during the diurnal changes. The conditional correlation between gs and Tr of wheat evoked new thinking on the relationships among gs, PN and Tr. Path analysis was further carried out to clarify the correlations of gs with the four atmospheric factors, that of Tr with gs and the four factors and the direct and indirect effects of the factors, during their diurnal dynamic variation. The effects of these factors on gs or Tr were related to RH. All the four factors had a much higher correlation with gs under HRH than that under LRH and MRH. Air temperature (T) had a rather higher direct effect than RH and photosynthetically active radiation (PAR). Also, the other factors had a much higher indirect effect on gs through vapor pressure deficit (VPD) and T. Transpiration rate was highly correlated with gs under LRH and MRH, with gs having a higher direct effect on it. In comparison, Tr was not correlated with gs under HRH but highly correlated with the atmospheric factors, with T, RH, and PAR having a higher indirect effect through VPD.

Impacts of Deficit Irrigation on Photosynthetic Performance, Productivity and Nutritional Quality of Aeroponically Grown Tuscan Kale (Brassica oleracea L.) in a Tropical Greenhouse

“…However, in this study, all plants had similar T r (Figure 1D). These results were similar to those reported by Zhang et al [37] in wheat. There was no correlation between stomatal conductance, g s and transpiration rate, T r in wheat during their diurnal variation under high air relative humidity, RH (36.7%), although g s was significantly correlated with T r under lower RH (15.4%) and moderate RH (28.3%).…”

“…There was no correlation between stomatal conductance, g s and transpiration rate, T r in wheat during their diurnal variation under high air relative humidity, RH (36.7%), although g s was significantly correlated with T r under lower RH (15.4%) and moderate RH (28.3%). According to Zhang et al [37], Tr was not correlated with g s under high air RH but highly correlated with other atmospheric factors such as temperature and photosynthetically active radiation (PAR) in wheat. In this study, measurements of A sat g s sat , C i and T r were taken with an average RH of 50% ± 3% and an ambient temperature of 38 ± 1 • C, which were similar to the conditions inside the greenhouse.…”

A Transcriptome Analysis Revealing the New Insight of Green Light on Tomato Plant Growth and Drought Stress Tolerance

“…Furthermore, the g s depends on the aperture, size, and density of stomata in plants (Monda et al, 2016 ). Thus, g s of plants is not always correlated with Tr and stomatal aperture, especially under different abiotic stress conditions (Durand et al, 2019 ; Zhang et al, 2020 ).…”

Assessment of leaf morphological, physiological, chemical and stoichiometry functional traits for understanding the functioning of Himalayan temperate forest ecosystem

“…A has a positive relationship with E 51 for the management of leaf temperature 54 , 55 , and a negative relationship with Gs 35 , 38 . The stomata alter the aperture in response to external conditions in order to maximize the photosynthesis-water loss tradeoff 56 , and are therefore strategically linked to Chl and A. The responsiveness of leaf functional features to environmental variables, i.e.…”