Determination of Physiological Stress Thresholds for Improved Selection of Drought Resistant Wheat Genotypes
2022
Sharma, Gopal | Brar, Gurcharn | Knipfer, Thorsten
Non-Peer Reviewed
显示更多 [+] 显示较少 [-]Drought induced water stress leads to dehydration of wheat plants affecting performance and productivity. However, the underlying physiological stress thresholds remain elusive across wheat genotypes which limits our ability for drought selection. We performed our study on Superb (rated as 'drought susceptible' in terms of yield potential), Stettler and AAC Viewfield (both rated as 'drought tolerant'). Plants were grown in large cylindrical pots to minimize root growth restrictions. A drought-stress treatment was imposed at early anthesis. Over the drydown period wheat water relations were assessed by measurement of water potential at predawn and midday, leaf relative water content, and solute potential of leaf sap. This was combined with visual quantification of the onset of leaf rolling. Our data highlights that osmotic adjustment (OA) occurred in AAC Viewfield which was linked to a genotype-specific si gnature of soil moisture thresholds. In contrast, OA was absent and several soil moisture thresholds coincided in Stettler and Superb. In conclusion, our data point to genotype-specific physiological signature and water requirements to maintain hydration status.
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