| The seed germination characteristics of Sophora flavescens Ait as well as the physiological and growth and development changes under water and salt-alkaline stress are carried out in this paper, which can provide us the knowledge of water and salt-alkaline tolerance mechanism and the optimum condition for seed germination.The major results were as follows:1. As far as the germination rate was concerned, the treatment of 98% concentrated sulfuric acid treatment(30min) was the best and the germination rate reached 82.0%; the second effective method was the way of dipping in water of 60℃, was 65.3%; the last was the way of destroying the seed-coat by sandpaper rubing, the germination rate was 55.3%. Compared to the control treatment (16.0%), the above treatments all had significant higher germination rate (p<0.05).2. Seed hardness declined significantly after being treated by 98% concentrated sulfuric acid while the germination rate increased with the treated time prolonged. However, the optimum treated time was 40 minutes as a result of the best seedling growth and germination rate was 86.7%.3.The seed germination of Sophora flavescens Ait is sensitive to temperature.The germination rate was 57.3%,68.0%,80.0% and 85.3% when the temperature was settled as 15℃,20℃,25℃and 30℃. The average fresh weight per seedlings was 115.5㎎,139.2㎎,171.2㎎ and 182.5㎎ after 10 days treatment.Combined with seedling morphology evaluation, 25℃was considered as the optimum temperature of Sophora flavescens Ait seed germination. At the same temperature and different illumination conditions, there was no significant difference among the germination rate, which means illumination is not essential to Sophora flavescens Ait seed germination.4.The status of seed germination and seedling growth of Sophora flavescens Ait were studied under different concentrations of NaCl stress in this paper. The results showed thatcompared to the CK, the germination potential as well as germination rate was higher under low NaCl concentrations(<0.5%),while lower under high NaCl concentrations(>0.7%).With NaCl concentrations increasingboth seed germination index and vigor index of seedling were decreased gradually. NaCl inhibited the seedling of Sophora flavescens Ait via decreasing the radicle length, hypocotyls length and seedling fresh weight.5. Pot experiment was carried out to study the variations of physiological and plant growth response to water stress. The results showed that water deficit had different influences on the seedling growth of Sophora flavescens Ait. The seedling height,leaflet number,leaf area,the fresh weight of aboveground as well as dry weight all decreased with the soil moisture decreased based on the control treatment. The mild stress had a little influence, while moderate and severe stress both had significantly influence. The root growth as well as root activity of Sophora flavescens Ait dropped with soil moisture decrement, and the root activity reduced 19.5%,36.8% and 51.9% respectively under mild,moderate and severe strees treatment. But the proline and MDA in leaves showed contrary, which increased with soil moisture decrement.6. The tolerance of Sophora flavescens Ait seedlings to saline-alkali was studied by pot experiment with applying 1.0g/L,3.0g/L,5.0g/L and 7.0g/L NaCl neutral salt and alkaline salt Na2CO3. The results showed that Sophora flavescens Ait seedlings to the maximum concentration of NaCl-resistant was 3.0g/L, and the maximum tolerance to Na2CO3 was 7.0g/L. leaves osmolyte proline,MDA and soluble sugar content were all increased with the increasing concentration of NaCl and Na2CO3 at certain salt concentration. The neutral salt impact was stronger than that of alkaline salt,that is to say the Sophora flavescens Ait tolerance to alkaline salt is stronger than the neutral salt.
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