Effects of Drought Pretreatment on Physiological Characteristics of Peanut Seedlings under Salt Stress

Gao Rongrong; Guo Feng; Zhang Yi; Yang Sha; Zhang Jialei; Tang Zhaohui; Geng Yun; Meng Jingjing; Li Xinguo; Wan Shubo

doi:10.14083/j.issn.1001-4942.2018.06.013

Abstract：In order to explore the effects of drought pretreatment on physiological characteristics of pea-nut (Arachis hypogaea),the cultivars HY25 and HY22 with high and low salt resistance respectively were used as experimental materials.Indoor sand culture experiments were conducted to study the effects of drought pretreatment on the relative water content,photosynthetic performance,protective enzyme activity and osmotic adjustment substance contents of leaves and root activity under salt stress with pretreatment of rehydration after drought treatment.The results showed that salt stress increased the contents of malondialdehyde (MDA),pro-line and soluble sugar in leaves of the two cultivars seedlings,reduced the relative water content,chlorophyll content,maximum photochemical efficiency and photochemical quenching coefficient.With the time of stress going on,the superoxide dismutase (SOD)activity,peroxidase (POD)activity and root activity increased firstly,then decreased and finally lower than those of control.Compared with no drought pretreatment, drought pretreatment increased the relative water content,antioxidant enzyme activity and osmotic regulation substance content of leaves and root activity,reduced the content of MDA and weakened the influences on chlorophyll fluorescence parameters of the two cultivars seedlings under salt stress.These results showed that drought pretreatment could improve the leaf relative water content and photosynthetic rate of peanut,enhance the role of osmotic adjustment,improve the activities of protective enzymes,decrease cell membrane lipid per-oxidation and ensure the integrity of cell membrane to maintain normal cell metabolism,thus effectively re-duced the damage of salt stress to peanut seedlings.