Screening and Physiological Analysis of Fresh-eating Corn with Waterlog-ging Tolerance at Seedling Stage
The occurrence of waterlogging in fresh maize seedling stage can cause a relatively large yield reduc-tion,and improving the waterlogging resistance of fresh maize seedling stage through genetic improvement is an effective way to cope with flooding stress.In this study,241 fresh maize inbred lines were used as research materi-als,and the change rate of plant height and plant dry weight of inbred lines at seedling stage under flooding stress was used as the evaluation index to screen the waterlogging-resistant and flooding-sensitive fresh maize inbreds 20 copies each.In addition,under flooding stress,the changes of photosynthetic indexes,stress-related physiological indexes and flood-tolerance-related marker genes ZmP4H4,Sicyp51 and ZmbRI were analyzed in the leaves of the screened varieties at seedlin g stage.The results showed that there were significant differences between the flood-sensitive inbred lines and the flood-resistant inbred lines for photosynthetic indicators.There was no signifi-cant difference in the content of malondialdehyde between the flood-resistant inbred line treatment and the control(P=0.360 3),but there was a significant difference in the content of hydrogen peroxide(P=0.045 6),and there was an extremely significant difference in the content of proline(P=0.016).There were significant differences in the content of malondialdehyde(P=0.047 9)and proline(P=0.036),and the content of hydrogen peroxide(P=6.63E-06)be-tween the flood-sensitive inbred lines and the control.The expression of waterlogging tolerance-related genes changed significantly between the flood-tolerant inbred line treatment and the control,while the waterlogging tol-erance-related gene expression did not change significantly between the flooding-sensitive inbred line treatment and the control.The results of this study have important implications for maize breeding for flood tolerance.