NaCl胁迫下西瓜种子对蛭石引发的响应

Response of Watermelon Seed to Solid Matrix Priming under NaCl Stress

以西瓜品种“小皇冠”和“早佳8424”种子为试验材料,采用种子萌发袋发芽的方法,研究在不同浓度(0,50,75,100,125 mmol/L) NaCl溶液胁迫下,蛭石引发处理对西瓜种子发芽指标及幼苗生理特性的影响,探讨引发处理对缓解西瓜盐胁迫伤害的可行性。结果表明,随着NaCl浓度增加对西瓜种子萌发的抑制作用逐渐加剧,引发处理提高了NaCl胁迫下西瓜种子发芽势和发芽率;NaCl胁迫下,西瓜胚根超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性升高,过氧化氢(H_(2)O_(2))、丙二醛(MDA)和可溶性糖含量增加;引发处理下胚根的SOD、POD、CAT活性增强,MDA和H_(2)O_(2)含量减少,可溶性糖含量增加。研究表明,引发处理能促进NaCl胁迫下西瓜种子萌发,促进可溶性糖的积累,诱导抗氧化酶活性,降低MDA和H_(2)O_(2)的积累,增强西瓜幼苗的耐盐性。

In order to explore the feasibility of priming treatment to alleviate the damage of watermelon seedlings under salt stress,the seeds of watermelon varieties"Xiaohuangguan"and"Zaojia 8424"were used as experimental materials,and the seed germination bag method was used to study the effects of vermiculite priming treatment on seed germination and physiological characteristics of watermelon seedlings under different concentrations(0,50,75,100,125 mmol/L)NaCl stress.The results showed that under salt stress,the inhibition of germination of watermelon seed was aggravated with the increase of salt concentration,and the priming treatment increased the germination potential and germination rate of watermelon seeds under salt stress.Under salt stress,the activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)in radicles of watermelon increased,and the contents of hydrogen peroxide(H_(2)O_(2)),malondialdehyde(MDA)and soluble sugar increased.The activities of SOD,POD and CAT in radicles of priming treatment increased.The content of MDA and H_(2)O_(2) decreased,while the content of soluble sugars increased.Study indicated that priming could promote the germination of watermelon seeds under salt stress,promote the accumulation of soluble sugar,induce antioxidant enzyme activity,reduce the accumulation of MDA and H_(2)O_(2),and enhance the salt tolerance of watermelon seedlings.