Response of Avena Species leaf photosynthesis and stomatal conductance to water stress

Effect of water stress on photosynthesis was evaluated in seven Avena species under pot culture environment. Imposed water stress decreased photosynthetic rates and stomatal conductance. A. sativa L. maintained higher photosynthetic rate, stomatal conductance and P_N/C_i ratio under water stress during vegetative and flowering stages of crop growth indicating its suitability for moisture stress environment as compared to other species. However, the reduction in photosynthetic rates was low in A. brevis followed by A. strigosa at vegetative stage and A. abyssinica followed by A. strigosa and A. sativa at flowering stage indicating their relative drought tolerance potential. Significant correlations were observed between P_N and stomatal conductance and P_N and leaf water potential indicating the interdependence of these traits.