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Differential root responses in two cultivars of winter wheat (Triticum aestivum L.) to elevated ozone concentration under fully open‐air field conditions
- Kou, T.‐J., Yu, W.‐W., Lam, S. K., Chen, D.‐L., Hou, Y.‐P., Li, Z.‐Y.
- Journal of agronomy and crop science 2018 v.204 no.3 pp. 325-332
- Triticum aestivum, biomass, cell respiration, crop yield, cultivars, filling period, heading, ozone, soil respiration, surface area, troposphere, winter wheat
- The effect of elevated tropospheric ozone concentration [O₃] on root processes in wheat systems of different O₃ sensitivity is not well understood. Two wheat cultivars (cv. Y15 and YN19) with contrasting O₃ tolerance were grown in a fully open‐air O₃ enrichment platform for one season. We found that elevated O₃ (EO₃) (50% above the ambient O₃) significantly decreased the total biomass at all key growth stages and the yield of the O₃‐sensitive cultivar YN19 but did not affect those of the O₃‐tolerant cultivar Y15. EO₃ significantly decreased the root biomass of two wheat cultivars at the jointing and grain‐filling stages. EO₃ significantly decreased the root length, length density, surface area and volume of the two cultivars at the jointing stage but increased those of YN19 at the grain‐filling stage. EO₃ significantly increased the root activities (specific root respiration rates) of Y15 and YN19 at the jointing, heading and grain‐filling stages. EO₃ significantly decreased the contribution of fresh root respiration to soil respiration (CRS) of YN19 at the jointing stage but increased it at the heading stage; however, it did not change the CRS of Y15 at any growth stages. This study indicates that the effects of EO₃ on root morphology and activity varied among wheat cultivars, and suggest that we can breed O₃‐tolerant cultivars to maintain crop yield under higher [O₃] scenarios.