Alleviation Effect of Exogenous Nitrate Fertilizers on Maize Seedlings under Waterlogging Stress
Here we explored the alleviation effect of exogenous nitrate fertilizers by foliar application on maize seedlings under waterlogging stress using the cultivar Zhengdan 958 as material.The results showed that the plant height(PH),fresh weight(FW)and dry weight(DW)of maize seedlings were significantly re-duced under waterlogging stress(T1)for 7 days compared to the control(CK).After spraying KNO3 solution under waterlogging stress(T2),the FW and DW of shoots and roots of seedlings were significantly increased by 21.7%and 45.5%,and 32.9%and 49.6%,respectively,compared with T1.A slight increase in FW and DW of seedlings was found after spraying Ca(NO3)2 solution under waterlogging stress(T3)compared with T1.Compared with CK,the contents of MDA and H2 O2 under T1 treatment increased significantly after the 5 days,and also increased before.External application of nitrate nitrogen fertilizers significantly reduced oxida-tive stress.On the 5th day,the contents of MDA and H2 O2 under T2 treatment were 9.1%and 14.9%lower than those under T1 treatment respectively,and those under T3 treatment were 2.1%and 14.6%lower.The soluble sugar and soluble protein contents decreased slightly,but proline content increased significantly under T1 treatment compared to CK.The soluble sugar content on the 1st and 5th days of T2 treatment increased sig-nificantly by 44.5%and 23.8%compared with T1 treatment,and the proline content was also significantly en-hanced.The soluble sugar content on the 1st day of T3 treatment increased significantly by 36.5%compared with T1 treatment.Compared with CK,the activity of antioxidant enzymes under T1 treatment decreased,and most reached significant level.The external application of nitrate nitrogen fertilizers increased the activities of antioxidant enzymes under waterlogging stress.The SOD,POD and CAT activities in maize leaves under T2 treatment for 5 days increased by 25.1%,12.4%and 22.1%respectively compared with T1 treatment.The SOD and POD activities under T3 treatment for 5 days increased by 6.4%and 52.9%respectively,but the CAT activity decreased slightly compared with T1 treatment.Taken together,the alleviation effect of spraying KNO3 on waterlogging stress was stronger than that of spraying Ca(NO3)2.
万方数据
维普
