Effect of sodium selenate spraying on seed selenium content and some physiological indices of rapeseed genotypes (Brassica napus L.)

Selenium is a non-metallic element that has an effect on the growth and development of plants and, due to its presence in antioxidant systems, improves the growth and physiological traits of plants. For this purpose, an experiment was conducted based on a randomized complete block design with split-plot split plot with three replications during two years of cultivation 2014-15 and 2015-16 in research farm of Seed and Plant Improvement Research Institute, Karaj, Iran. Selenium spraying (from sodium selenate source) in main plots in two levels of control (without spraying) and spraying 30 g/L in two stage  in pre-flowering and six genotypes of autumn rapeseed in sub plots were compared. The effect of year, selenium spraying, and genotype were significant on proline content, soluble carbohydrate, photosynthetic pigmentation, selenium content, seed oil and grain yield. Application of selenium resulted in increased proline (6.68%), carbohydrate (7.26%), chlorophyll a (8.65%), total chlorophyll (7.44%), selenium grain (79.87%), seed oil (0.89%), and grain yield (8.1%) compared to the control treatment. The proline content of leaf in 2014-15 year was significantly higher and equal to 69.63% more than in 2015-16 year. The highest oil content and grain yield were observed in SW102 genotype with average of 7.47% and 2060.6 kg/ha, respectively. Generally, the results showed that cultivating SW102 and Elvis genotypes under selinum sparying conditions caused the optimal content of oil and grain yield, which is recommended for the area under test.