Growth and physiological responses of Canavalia maritima seedlings to water stress

Abstract

[Objective] The study aims to explore the growth and physiological response of Canavalia maritima seedlings to water stress, and provide a reference for water management during the seedling stage and for the cultivation of high-quality plants in coastal sandy lands. [Methods] One-year-old C. maritima seedlings were subjected to simulated drought stress (soil relative water content at 20%, 40%, and 60%), suitable water condition (80%, control), and waterlogging (100%) with water control experiment in pots. Their growth and physiological indices were analyzed. [Results] Under both drought and waterlogging stress, leaf dry weight was decreased, while leaf relative water content was increased. Seedling height and leaf area were increased under waterlogging but decreased under severe drought stress. Total root length, total root surface area, total root volume, and mean root diameter were increased under drought stress and decreased under waterlogging. The content of malondialdehyde and the activities of catalase (CAT) and peroxidase (POD) were increased, while the activity of superoxide dismutase (SOD) was relatively stable. Soluble protein content was decreased, whereas soluble sugar and proline contents were increased under water stress. The chlorophyll content was decreased under severe drought stress. Initial fluorescence was increased, while maximum fluorescence, maximum photochemical efficiency, and maximum quantum yield were decreased under water stress. [Conclusion] C. maritima seedlings demonstrate strong tolerance to drought and waterlogging stress by altering water accumulation and distribution patterns, increasing the activities of CAT and POD, and enhancing soluble sugar and proline contents.

Keywords

• canavalia maritima
• water stress
• growth
• physiological indicators