Effect of Ca2+ on seed germination and seedling physiological characteristics of cucumber.

The effect of different Ca2+ concentration on the seed germination and seedling growth of cucumber (Cucumis sativus L.) had been studied.The results showed that Ca2+ of lower concentration(0-0.05 mg/L) could promote the seed germination and seedling growth of cucumber.It was beneficial to seed germination and seedling growth of cucumber by using 0.05 mg/L Ca2+ concentration,and the germination rate,germination index,vigor index,length of root,length of hypocotyls,diameter of hypocotyls and water content of seedlings were higher than those of control and other Ca2+ concentration,and the MDA content,soluble sugar content,plasma membrane relative permeability,proline content and POD activity of cucumber seedling were decreased.But after 0.5 mg/L,the physiological indicators of seed germination decreased with the increase of Ca2+ concentration and those of seedling growth increased.The high concentration of Ca2+ had an inhibition effect on the seed germination and seedling growth and had the largest inhibition effect at 2.0 mg/L.