Photosynthetic Diffusional Constraints Affect Yield in Drought Stressed Rice Cultivars during Flowering

摘要: Global production of rice (Oryza sativa) grain is limited by water availability and the low ‘leaf-level’ photosynthetic capacity many cultivars. Oryza sativa extremely susceptible to water-deficits; therefore, predicted increases in frequency duration drought events, combined with future rises global temperatures food demand, necessitate development more productive tolerant We investigated underlying physiological, isotopic morphological responses water-deficit seven common varieties O. sativa, subjected prolonged varying intensities, for phenotyping purposes open field conditions. Significant variation was observed leaf-level photosynthesis rates (A) under both treatments. Yield A were influenced conductance mesophyll layer CO2 (gm) not stomatal (gs). Mesophyll declined during differing extents among cultivars; those that maintained gm sustained yield a greater extent. However, variety highest well-watered conditions (IR55419-04) distinct from most effective cultivar (Vandana). effectively characterises cultivars conditions; however, desired attributes high optimal growth remain constant may be mutually exclusive. Nonetheless, genetic physiological studies aimed at enhancing stress tolerance should investigate biochemistry morphology interface between sub-stomatal pore layer.