等离子体处理对紫云英种子萌发和生理特性的影响

Effects of dialectric barrier discharge plasma treatment on seed germination and physiological characteristics of Astragalus sinicus

为打破紫云英种子硬实,提高种子活力和发芽一致性,本研究以赣紫75-3-51和信紫1号为供试材料,采用室内发芽试验探讨了不同剂量等离子体处理(7、8、9 kV电压分别处理1、3、5、10 min)对紫云英种子活力、幼苗生长、抗氧化酶活性以及渗透调节物质含量的影响,以期为紫云英种子播前处理技术提供参考。结果表明:等离子体处理对2种紫云英种子的发芽率和发芽势没有显著影响,但提高了紫云英种子活力。不同品种紫云英对等离子体处理的响应存在差异。等离子体处理对赣紫75-3-51生长存在低促高抑的现象,幼苗鲜重以及胚芽长度均随处理时间增加呈单峰曲线变化。信紫1号幼苗鲜重在高剂量(9 kV处理10 min)等离子体处理条件下显著降低,较对照降低了20.5%。赣紫75-3-51幼苗的超氧化物歧化酶和过氧化物酶的活性随处理电压和时间的增加均表现为先升高后下降的变化趋势。信紫1号的两种抗氧化酶活性在低电压下(7 kV)随处理时间增加呈上升趋势,而在高电压下无显著变化。此外,低剂量等离子体处理提高了2种紫云英幼苗渗透调节物质含量。虽然等离子体处理对供试紫云英萌发无显著影响,但适宜的等离子体处理可激发紫云英种子抗氧化酶活性,促进大分子糖类和蛋白质的溶解,从而提高紫云英种子活力,促进幼苗生长。

Poor seed germination and seedling performance when germinated in commonly encountered osmolyte concentrations are major constraints to expansion of Astragalus sinicus cultivation.The objective of this study was to test the potential use of an electrical discharge plasma treatment as a low-cost technology for sustainable A.sinicus cultivation.Two cultivars of A.sinicus(Ganzi 75-3-51 and Xinzi 1)were investigated in an indoor germination experiment in order to investigate the influences of various dielectric barrier discharge plasma treatments(7,8 or 9 kV for 1,3,5 or 10 min)on A.sinicus seed germination,seedling growth,antioxidant enzyme activity and osmolyte concentrations.It was found that plasma treatments had no significant effects on the germination rate or germination potential of A.sinicus seed,but did raise the germination index and seed vigor index of both cultivars.Significant interactions between plasma and cultivar effects were observed for most traits indicating that the response patterns of the cultivars across the imposed plasma treatments were different.The growth of Ganzi 75-3-51 seedlings was promoted with lower-dose plasma treatment and inhibited with higher-dose plasma treatment.Xinzi 1 seedlings were sensitive to plasma treatment and high dose plasma treatment(9 kV with 10 min duration)significantly reduced the fresh weight of Xinzi 1 seedlings(the decrease,as compared with the controls was 20.5%).The activities of superoxide dismutase and peroxidase of Ganzi 75-3-51 tended to rise initially and then decline with increase in voltage and treatment time.The antioxidant enzyme activity of Xinzi 1 showed a trend of increase with increased exposure time in the low-voltage plasma treatment(7 kV),but wasn’t significantly changed by high-voltage plasma treatment.In addition,low dose plasma treatment enhanced the contents of soluble sugar and protein in seedlings of both A.sinicus cultivars.Though plasma treatment didn’t significantly affect the germination of tested A.sinicus cultivars in the current study,some plasma treatments did stimulate antioxidant enzyme activities,and promote starch and protein hydrolysis,thereby improving the seed vigor and growth of A.sinicus seedlings.