外源烯效唑对干旱胁迫下马铃薯叶片抗氧化能力及渗透调节的影响OA

To study the effect of exogenous Uniconazole on physiological parameters of potato leaves under drought stress,a pot experiment was carried out in the potting field of Keshan Branch of Heilongjiang Academy of Agricultural Sciences in 2022 using drought-sensitive variety Atlantic as the experimental material.Uniconazole and drought treatments were carried out during the tuber expansion period(the second inflorescence flowering).Four treatments were set up as follows:normal water management(CK),normal water management + Uniconazole spraying(CK+S),drought stress(D)and drought stress + Uniconazole spraying(D+S).Samples were collected after 15 days of Uniconazole spraying.The effect of exogenous Uniconazole on the growth,active oxygen accumulation,antioxidant enzyme activity,ascorbate-glutathione(ASA-GSH)cycle and osmotic adjustment substance content of potato leaves under drought stress were analyzed by correlation analysis and principal component analysis.Results showed that exogenous Uniconazole could significantly improve the growth of potato leaves.Compared with D treatment,the contents of chlorophyll a(Chl a)and total chlorophyll(Chl a+b)in leaves treated with D+S increased significantly by 16.52%and 13.85%,respectively.Uniconazole spraying reduced MDA,O2-production rate and H2O2 content in leaves,but increased antioxidant enzyme activity and ASA,GSH,DHA and GSSG content in ASA-GSH cycle,result in a removal of excessive accumulation of ROS and reduced membrane lipid peroxidation.In addition,exogenous Uniconazole could significantly increase the content of soluble protein and proline in leaves,and also alleviate the inhibitory effect of drought stress on leaf growth.Furthermore,exogenous Uniconazole can promote the synergistic effect between antioxidant enzymes,ASA-GSH cycle and osmotic regulation in potato leaves,thereby improving the level of reducing power and antioxidant capacity in leaves,reducing the damage caused by reactive oxygen species to cell membranes,and improving potato drought tolerance.This study provides more scientific basis for drought-resistant cultivation of potato and application of Uniconazole.