Abstract: A germination test was conducted  to understand the effects of seed priming on seed germination and early seedling growth of sweet sorghum (M-81E). The hydrationdehydration processes of M81E were analyzed with KCl or CaCl₂ solution (50, 100, or 200 mmol·L^-1) or isosmotic PEG solution being used for pretreatment, and the germination percentage, germination rate, seedling growth, biomass allocation, and Na⁺, K⁺ and Ca²⁺ contents in different NaCl solutions were determined after seed priming. The results showed that the first 3 hours of hydration and dehydration processes of M81E were the quick water absorption period and quick dehydration period. The germination percentage and germination rate were not significantly different when the NaCl stress was lower than 200 mmol·L^-1. The different priming conditions had no significant effects on the germination percentage and germination rate except the positive effect of CaCl₂ pretreatment to the germination rate in 50 and 200 mmol·L^-1 NaCl solutions. However, the seed priming significantly affected the radical length, hypocotyl length and the whole seedling length. Seed priming had negative effects on seedling growth in nonsalt treatments but significantly improved the seedling growth with the increase of salt concentration, and the different pretreatment reagents had different effects on seedling growth. The contents of Na⁺ and Ca^2+ in seedlings were significantly increased with the increase of salt concentration, but not for the content of K⁺. Seed priming significantly decreased the content of K⁺, with the exception of KCl pretreatment. In conclusion, the different pretreatment reagents increased the seedling growth, biomass accumulation and the capacity of ion adjustment to different extents. The seed priming effect of CaCl₂ solution was better than that of the other two solutions.

Key words: water use efficiency, chlorophyll fluorescenceSymbol characteristics, micro-sprinkling hose length and width, wheat, water characteristics, grain yield