Effects of waterlogging stress on the physiological response and grain-filling characteristics of spring maize (Zea mays L.) under field conditions

A field experiment was implemented to discuss the effects of waterlogging and subsurface waterlogging stress on the grain yield, grain-filling characteristics, superoxide anion (O2·-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{O}}_{2}^{ \cdot - }$$\end{document}) content, hydrogen peroxide (H2O2) content, malondialdehyde (MDA) content, antioxidant enzyme activity, proline, soluble protein content and SPAD value of the spring maize (Zea mays L.) hybrids “Demeiya1” (DMY1) and “Keyu16” (KY16). The waterlogging and subsurface waterlogging treatments were conducted for different durations (3, 6, and 9 days and 5, 10, and 15 days, respectively) at the seedling (V3), jointing (V6), and tasseling (VT) stages. The results showed that the most significant effects of waterlogging and subsurface waterlogging stress occurred at the V3 stage, followed by the V6 stage and then VT stage. Waterlogging and subsurface waterlogging caused a decline in grain filling, which resulted in a decline in grain weight and ultimately caused an obvious decrease in yield. The content of O2·-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{O}}_{2}^{ \cdot - }$$\end{document} and H2O2 as well as MDA increased with the prolongation of the duration of waterlogging and subsurface waterlogging, which caused an up-regulation of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities, as well as increased proline and soluble protein contents and decreased SPAD value. In addition, we also demonstrated that KY16 is more sensitive than DMY1 to waterlogging and subsurface waterlogging.