Effect Of Sodium Nitroprusside And Low Temperature Pretreated On Physiological Characteristics Of Oat Seedling Under Salt Stress

This research use Qingyan No.1, Qingyin No.2and Lena as materials,under150mmol/LNaCl stress condition,studied the effect of the different concentractions at0.05,0.10and0.20mmol·L-1Sodium Nitroprusside (exogenous nitric oxide),low temperature(5℃) and combinedSodium Nitroprusside wtih low temperature on the salt stress tolerance of three oat varietiesseedling leaves(1)The effects of different concentrations of NaCl on seed germination ratio,shootlength,root number and root length of three oat varieties were studied. And came to a conclusionthat The low concentration of salt（50mmol/L NaCl）has promoting effect on the germinationof oat, and increasing concentrations exhibited obvious inhibition.Through comprehensiveanalysis and determined that the150mmol/L NaCl is the most suitable concentration of saltstress;（2）The effects of Sodium Nitroprusside in three oat varieties seedling leaves before andafter under150mmol·L-1NaCl stress were studied through measured the contents of chlorophylland MDA and the activities of antioxidant enzymes(SOD、POD and CAT).The results showedthat treatment of NaCl stress with different concentrations of SNP(0.05,0.10and0.20mmol·L-1)increased the activities of SOD、POD and CAT and the contents of chlorophyll and decreasedMDA contents in three oat varieties leaves in different degree compared with salt stresscontrolled seedling leaves. Futhermore the effects of SNP for allevation of150mmol·L-1NaClstress were dose-dependant. The treatment of0.10mmol·L-1SNP is most significant and thiseffect is variental difference, Qingyin No.2was treated best.(3) Through measured the contents of chlorophyll and MDA and the activities of antioxidantenzymes(SOD、POD and CAT) under the salt stress condition after low temperature pretreatedthree oat varieties seedlings,we found that cross-adaptation exists in three oat varietiesseedlings.Furthermore, the low temperature pretreatment caused the change of the activities ofantioxidant enzymes, then improved the salt resistance of three oat varieties,these indicate thatthe improvement of salt stress tolerance is often related to the enhancement of activity ofantioxidant enzyme system in oats, in other words, we suggest that antioxidant enzyme system play an important role in the course of cross-adaptation in oats.(4)The effect of low temperature combined with different concentrations of SNP(0.05,0.10and0.20mmol·L-1) were studied through measured the contents of chlorophyll and MDA and theactivities of antioxidant enzymes.The results showed that combined low temperature withdifferent concentrations of SNP(0.05,0.10and0.20mmol·L-1) could increase the salt stresstolerance of the three oat varieties, and the best effect was observered in the treatment ofcombined0.10mmol·L-1SNP with the low temperature pretreatment,improved the salt stresstolerance of three oat varieties seedlings most obviously.On the other hand,these indicate thatthe nitric oxide may be the signal of the cross-adaptation.(5) Combined0.10mmol·L-1SNP with the low temperature pretreatment is the best effectthrough a comprehensive comparison of the three methods,it could largely increase oatstolerance to salt stress.