种子引发对高粱幼苗耐盐性的生理效应

Physiological Effects of Seed Priming on Salt Resistance of Sorghum Seedlings

【目的】探讨种子引发对高粱幼苗耐盐性及其生理效应的影响。【方法】用100mmol·L-1NaCl溶液和20%PEG溶液对甜饲1号、Tx623A×89-363、黑30A×05-244和晋杂17共4个高粱杂交种进行引发处理。采用营养沙培试验,设置0、50、100和150mmol·L-1NaCl溶液模拟盐胁迫。研究引发处理对NaCl胁迫下,种子发芽、幼苗耐盐性及其幼苗生理效应的影响。【结果】引发处理不同程度提高了4个品种幼苗的耐盐指数和耐盐比率。提高了盐胁迫下种子的发芽势、发芽率、发芽指数、活力指数,且以NaCl溶液引发效果最明显。在100mmol·L-1NaCl溶液胁迫过程中,特别是在盐胁迫后期,经NaCl溶液引发处理后,4个品种幼苗叶片SOD、POD活性和脯氨酸含量都比未引发处理高。【结论】采用合理的种子引发技术可以有效提高高粱苗期的耐盐性,解决盐渍地种植高粱出苗差、保苗难问题。种子引发通过提高盐胁迫下高粱幼苗保护酶活性及渗透调节物质含量等,增强了幼苗的耐盐性。

【Objective】 Physiological effects of seed priming on salt resistance of sorghum seedlings were studied in this paper. 【Method】 Four sorghum hybrids seeds （Tiansi No. 1,Tx623A×89-363,Hei 30A×05-244 and Jinza 17） were soaked in 100 mmol·L^-1 NaCl and 20%PEG solutions. Different degrees of salt injury were simulated with 0,50,100 and 150 mmol·L^-1 NaCl solution by methods of nutritional sand culture. After seeds priming,germination conditions,salt resistance and physiological effects on seedlings were studied. 【Result】 Priming treatment enhanced the tolerance index and tolerance ratio to some degree. At the same time,the germination potential,germination rate,germination index and activity index were improved obviously,especially for the NaCl priming. In the course of stress of 100 mmol·L^-1 NaCl solution,in particular the late stress,NaCl priming reduced MDA contents,enhanced SOD activities,contents of proline and soluble proteins in sorghum seedlings. 【Conclusion】 Seed priming technology could enhance the salt tolerance of sorghum seedlings which solved the problem of low germination rate and saving seedling rate in saline soil. The salt tolerance of sorghum seedlings was improved by increasing the activities of protective enzymes and contents of osmotic adjustment substances under the condition of salt stress.