Combined effects of high temperature and waterlogging on yield and stem development of summer maize

The purpose of this study was to identify the physiological mechanism underlying the effects of high tem-perature and waterlogging on summer maize. The stem development and yield of the maize hybrid Denghai 605 in response to high-temperature stress, waterlogging stress, and their combination applied for six days at the third-leaf, sixth-leaf, and tasseling stages were recorded. The combined stresses reduced lignin biosynthetic enzyme activity and lignin accumulation, leading to abnormal stem develop-ment. Reduction of the area and number of vascular bundles in stems led to reduced dry matter accumu-lation and allocation. Decreased grain dry weight at all three stages reduced grain yield relative to a control. In summary, high temperature, waterlogging, and their combined stress impaired stem develop-ment and grain yield of summer maize. The combined stresses were more damaging than either stress alone. (c) 2022 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).