Effects of Mixed Salt Stress on Germination Percentage and Protection System of Oat Seedling

In order to determine the effect of mixed salt stress on the germination rate of naked oat and protective enzymes of its’ seedling, in this study, using artificial culture box of climate, oat varieties (Yanke 1, Canadian 9, Big oat, Canadian 8, Canadian 6 and Baoluo) were cultivated in mixed salts solution. The results showed, with the increasing of concentration of double salts, the germination ratio and plant height decreased, semi-lethal concentration was between 1.5% and 2.6, utmost concentration was between 2.3 and 3.8%, respectively; the CAT activity of Big oat decreased, but that of other varieties increased first and then decreased, the peak value appeared when concentration of double salts was between 0.4 and 0.6%, respectively. And with the increasing of the concentration of double salt, POD activity and SOD activity of six oat varieties increased first and then decreased and its highest value appeared when concentration of double salts was between 1.2 and 1.8% respectively; the proline contents of all varieties increased, while the MDA contents decreased first and then increased and its minimum value appeared when concentration of double salts was 0.2%. To sum up, under the condition of salt stress, it was likely because of increasing of protective enzyme activity and proline contents to make salt tolerance of oats higher and salt tolerance of different varieties showed significant difference. The salt tolerance order showed that Yanke 1>Canadian 9>Baoluo>Big oat>Canadian 8>Canadian 6.