Effect of lanthanum on the germination and peroxidase activity in sorghum under acid-rain stress

The effect of lanthanum on the germination, MDA content and peroxidase (POD) activity in sorghum seeds under acid-rain stress were investigated. The objective of the study was to develop a scientific method and technical guide for mitigating acid-rain damage on seed germination. Results show that sorghum seeds germinate best when seed soaked in 12 mg·L^-1 La(Ⅲ) solution, damage on seed germination from acid-rain decreases. Germination rate, germination energy, germination index, vigor index are all higher than untreated seeds. Abnormal germination in treated seeds also tends to be lower than untreated, especially at pH 2.5. Because internal structure of seeds is destroyed by acid-rain with pH 2.0, La(Ⅲ) cannot reverse damage by acid-rain at pH 2.0. MDA content and POD activity of La(Ⅲ) treatment groups are lower than the non-La(Ⅲ) treatments, especially at pH 2.5 and 2.0. This indicates that La(Ⅲ) probably decreases membrane lipid peroxidation induced by acid-rain through POD activity adjustment, which eventually alleviates acid-rain damage on seed germination.