Effects of selenium as a beneficial element on growth and photosynthetic attributes of greenhouse cucumber

Selenium (Se) is an essential element for human and livestock with antioxidant and anticancer characteristics. Although Se is not an essential element for plants, it has been reported that it can improve plant growth. This experiment was conducted at the Isfahan University of Technology in winter 2010. The experiment was factorial based on a completely randomized design (CRD) with four replications. Se was added to nutrient solution in four concentrations 2, 4, and 6mg/L sodium selenite (Na2SeO3). Root volume, fresh and dry weights of shoots and roots, number and weight of fruits, chlorophyll content, and photosynthesis traits [photosynthesis rate, stomata internal carbon dioxide (CO2) concentration, stomata conductance] were measured. Results showed that Se increased root dry weight. Fresh and dry weights of shoot increased in the 2mg/L Se treatment and decreased at the higher level of Se. Chlorophyll content and photosynthesis rate were not affected by Se. Stomata internal CO2 concentration and stomata conductance decreased by Se addition. Overall, Se at 2mg/L application rate was effective in some physiological characteristics of cucumber.