外源Ca~(2+),ALA,SA和Spd对盐胁迫下紫苏种子萌发及幼苗生理特性的影响

目的:通过对紫苏种子萌发及幼苗生理特性的研究,寻找提高紫苏种子及幼苗在盐胁迫条件下抗性能力的途径。方法:测定NaCl胁迫下紫苏种子在不同浓度的外源钙离子(Ca2+)、5-氨基乙酰丙酸(ALA)、水杨酸(SA)和亚精胺(Spd)处理后,发芽势(Gv)、发芽率(Gr)、发芽指数(Gi)和活力指数(Vi)的变化。并对紫苏幼苗总生物量以及叶片丙二醛(MDA)含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性进行测定。结果:100 mmol.L-1的NaCl胁迫下的紫苏种子萌发受到显著抑制,但是经过Ca2+,ALA,SA,Spd处理后,萌发指标均有升高。外施Ca2+(10 mmol.L-1),ALA(100mg.L-1),SA(50 mg.L-1)或Spd(0.25 mmol.L-1)都能够有效的缓解NaCl对紫苏种子及幼苗造成的胁迫伤害,其中经过100 mg.L-1的ALA处理后,效果最为显著,各项指标均达到最大值,发芽势为65.3%,发芽率为89.7%,发芽指数为15.2,活力指数为为0.123 8。各处理均提高了幼苗的总生物量,降低了叶片的MDA含量,显著的提高了SOD,POD,CAT的活性,经过100 mg.L-1的ALA处理后3种酶的活性分别达到最大值(0.72,6.82,5.64 U.mg-1)。结论:适宜浓度的Ca2+,ALA,SA,Spd都能够有效的减缓NaCl胁迫对紫苏种子及幼苗产生的伤害,提高种子及幼苗的抗盐能力。

Effect of exogenous Ca2+, ALA, SA and Spd on seed germination and physiological characteristics of Perilla frutescens seedlings under NaCl stress

Objective : To find a method for improving the salt resistance of seeds and seedlings for Perilla frutescens under NaCl stress, seed germination and physiological characteristics of P. frutescens seedlings were studied. Method : Several physiological indexes of P. frutescens seeds treated with different concentrations of Ca²⁺, 5-aminolevulinic acid (ALA), salicylic acid (SA) and spermidine (Spd) under NaCl stress like the germination vigor, germination rate, germination index and vigor index were measured. And other indexes like the biomass of the seedlings, the content of malondialdehyde (MDA) in leaves, the activities of superoxide (SOD), peroxidase (POD) and catalase (CAT) were also measured. Result : The germination of P. frutescens seeds under NaCl stress (100 mmol·L^-1) was inhibited obviously. But after the treatment with Ca²⁺, ALA , SA and Spd, all germination indexes were increased. Ca²⁺ (10 mmol·L^-1), ALA (100 mg·L^-1), SA (50 mg·L^-1) and Spd (0.25 mmol·L^-1) could obviously alleviate the damage of salt stress to the seeds of P. frutescens. ALA (100 mg·L^-1) significantly increased all indexes. The germination vigor was 65.3%, the germination rate was 89.7%, the germination index and vigor index were 15.2 and 0.123 8, respectively. All treatments decreased the content of MDA in leaves. The activities of three enzymes including SOD, POD and CAT were all increased. ALA (100 mg·L^-1) had the enzymes activity reach the maximum with 0.72, 6.82 and 5.64 U·mg^-1, respectively. Conclusion : Ca²⁺, ALA , SA and Spd with appropriate concentration could significantly alleviate the damages to the seeds and seedlings of P. frutescens under NaCl stress and promote the salt resistance of the seeds and seedlings.