抗旱性藜麦幼苗对干旱胁迫的生理响应OA

To investigate the response of drought-resistant quinoa seedlings to drought stress,the strongly drought-resistant quinoa variety Longli No.1(LL1)and the new breeding line LQ18 were selected as experimental materials.PEG-6000 solution was used to simulate drought environment.Three treatments were set:normal irrigation(CK),mild drought stress(5%PEG-6000),and severe drought stress(20%PEG-6000).We investigated quinoa seed germination rate,germination potential,germination index;seedling plant height,leaf area,root length,aboveground and underground dry weights;soluble protein and proline contents;superoxide dismutase(SOD)and peroxidase(POD)activities;and malondialdehyde(MDA)content.The results showed that severe drought stress reduced plant height,leaf area,and aboveground dry weight in both varieties(lines),but increased root length,underground dry weight,and root-shoot ratio.Specifically,the reductions in leaf area and aboveground dry weight,as well as the increases in root length,underground dry weight,and root-shoot ratio were all smaller in LQ18 than in LL1.Under drought stress,the soluble protein content of LL1 gradually decreased,while that of LQ18 first increased and then decreased to a level with no significant difference from CK.Under severe drought stress,the proline content of both varieties(lines)significantly increased,and the proline content of LQ18 was significantly higher than that of LL1.Drought stress influenced the activities of SOD and POD and increased MDA content in both varieties(lines).Under severe stress,the SOD activity of LQ18 decreased slightly,whereas its POD activity increased significantly;furthermore,its MDA content remained significantly lower than that of LL1.