不同耐旱性甘薯不同类型根系的抗氧化特性分析

Antioxidant Characteristics of Different Sweetpotato Root Types with Different Drought Tolerance

为研究大田条件下甘薯不同类型根的抗氧化物质和抗氧化酶变化特性,揭示甘薯耐旱生理机制。本试验以耐旱性强的‘济薯21’(JS21)和耐旱性弱的‘济紫薯1’(JZS1)为材料,在遮雨棚中开展根系抗氧化特性动态变化研究。结果表明:在干旱条件下,JS21三类根系中的H_2O_2含量、O_2^-生成速率、Vc和多酚含量降幅均比JZS1大;在栽后70天前,JS21三类根系中SOD、CAT、POD、APX和PPO活性增幅比JZS1大,在栽后70天后,其根系中CAT、POD、APX和PPO活性降幅比JZS1小。纤维根中的H_2O_2含量和O_2^-生成速率最低,SOD、POD、CAT、APX和PPO活性最高;块根中H_2O_2含量最高,Vc和多酚含量及CAT、APX和PPO活性最低;柴根中O_2^-生成速率、Vc、多酚含量最高,SOD、POD活性最低。总之,栽后70天左右根系抗氧化能力最强,柴根中抗氧化物质含量最高,纤维根中抗氧化酶活性最高,耐旱性越强的品种抗氧化酶增加越快而降低越慢。

In order to research the variation characteristics of antioxidants and antioxidative enzymes in different sweetpotato root types in the field,and reveal the physiological mechanism of drought tolerance in sweetpotato,’Jishu21’（JS21）with strong drought tolerance and’Jizishu1’（JZS1）with weak drought tolerance were chosen as the experimental materials under normal and drought treatments in rain-shelter.The results showed that the decreasing range of H2O2 content,O2-generation rate,Vc and polyphenol content in three root types of JS21 was respectively larger than those of JZS1 under drought condition.The increasing range involving the activities of SOD,CAT,POD,APX and PPO in three root types of JS21 was lager than those of JZS1 within 70 days after transplanting（DAT）,but the decreasing range of CAT,POD,APX and PPO in three root types of JS21 was smaller than JZS1 70 days after transplanting（DAT）.H2O2 content and O2-generation rate were the lowest in fibrous root,and activities of SOD,CAT,APX and PPO were the highest in fibrous root of the two varieties.The H2O2 content was the highest in storage root,but Vc and polyphenol content and activities of CAT,APX and PPO were the lowest in storage root.Indexes of O2-generation rate,Vc and polyphenol content were the highest in thick root,but activities of SOD and POD were the lowest in thick root.The 70 DAT might be the time of the highest antioxidative capacity,and antioxidants content was higher in thick root,but antioxidantive enzymes were higher in fibrous root,antioxidative enzymes of the variety with stronger drought tolerance increased faster and decreased slower under drought condition.