外源水杨酸缓解西葫芦幼苗低温胁迫的效应

摘要

Seedlings of summer squash were sprayed on leaves with different concentration levels of exogenous salicylic acid.Effect of SA on relative electric conductivity,soluble sugar content,CAT activity,free water/bound water ratio in summer squash leaves under low temperature stress (15℃ and 5℃) were studied.The results showed that relative electric conductivity and free water/bound water ratio in summer squash leaves were decreased,soluble sugar content and CAT activities were increased in treatments of different concentrations of SA,which indicated that exogenous salicylic acid can relieve low temperature stress of summer squash seedlings.The treatment of 250 mg· L-1 SA had the best effect on relieving 5℃ low temperature stress of summer squash seedlings,but the treatment of 350 mg·L-1 SA had the best effect on relieving 15℃ low temperature stress of summer squash seedlings.%以四叶一心期西葫芦幼苗为试材,研究了外源水杨酸(SA)对低温(15℃和5℃)胁迫下西葫芦幼苗叶片相对电导率、可溶性糖含量、过氧化氢酶(CAT)活性、自由水/束缚水比值的影响.结果表明,西葫芦幼苗喷施150,250和350 mg·L-1 SA后,叶片相对电导率和自由水/束缚水比值降低,可溶性糖含量和CAT活性升高,外源SA能缓解低温对西葫芦幼苗的胁迫.5℃低温下,以250 mg· L-1 SA效果最好,而15℃低温下,以350 mg·L-1 SA效果最好.