Abstract: Pretreatment of maize (Zea mays L.,Qing No.3 and Da Huang) seeds with CaCl2 solution could increase survival rate of maize seedlings under chilling,heat,drought and salt stress.In contrast to this,pretreatment with the Ca2+chelator EGTA decreased survival rate of the seedlings under these stresses.The results demonstrated that the exogenous Ca2+ can improve maize seedlings multiresistance mentioned above.In addition,Ca2+ treatment of the seeds enabled the seedlings to keep relatively higher activity of glutathione reductase (GR) than that of Ca2+deficient treatment (control).EGTA treatment of the seeds led to more less of GR activity in the seedlings under these stress.It is obvious that GR is involved in the Ca2+enhanced the mutli resistance or the stress tolerances of the maize seedlings.

Key words: Ca2+