Effects of Chitosan Coating on Seed Germination and Salt-tolerance of Seedlings in Hybrid Rice(Oryza sativa L.)

Seeds of two hybrid rice combinations, Shanyou 10 and Eryoupeijiu, which were film-coated with 1.5% chitosan, 1.5% chitosan +10 mmol/L proline, and non-coated seeds were germinated in H 2O, 50 mmol/L, 100 mmol/L or 150 mmol/L NaCl solutions at 30℃. Germination percentage, activities of α, β-amylase, tolerance index, tolerance ratio and content of compatible solutes, proline, total soluble sugar, fructose and sucrose were determined. The results showed that chitosan coating significantly improved germination percentage and activities of β-amylase under normal (H 2O) or salt stress conditions, and decreased activities of α-amylase under salt stress conditions as compared with the control (non-coating treatment). Under salt stress conditions, activities of α, β-amylase increased in Coated or non-coated seeds with enhancement of NaCl concentrations, Chitosan coating also improved the tolerance index and tolerance ratio of seedlings, and increased the content of proline, total soluble sugar, fructose and sucrose in stressed seedlings. It was suggested that Chitosan coating was able to improve the salt tolerance of seedlings in hybrid rice. Coating with chitosan +10 mmol/L proline had little increasing effects on seed germination and the salt tolerance of seedlings. Shanyou 10 had higher salt-tolerance of seedlings than Eryoupeijiu.