Selenium toxicity in upland field-grown rice: Seed physiology responses and nutrient distribution using the μ-XRF technique

. The highest intensities Kα counts of Se were detected mainly in the endosperm and aleurone/pericarp. μ-XRF revealed the spatial distribution of sulfur, calcium, and potassium in the seed embryos. The seed germination decreased, and the electrical conductivity increased in response to high Se application rates showing clearly an abrupt decrease of physiological quality of rice seeds. This study provides information for a better understanding of the effects of Se toxicity on rice, revealing that in addition to the negative effects on yield, there are changes in the physiological and biochemical quality of seeds.