Morphological and photosynthetic characteristics of Cenchrus fungigraminus under different waterlogging stress

Global climate change has significantly altered precipitation patterns, leading to more widespread and severe waterlogging events, which have become a major obstacle for the development of industrial crops in riparian areas. Cenchrus fungigraminus , a crucial biomaterial and super energy plant in China and Africa is renowned for its high biomass, resilience, and excellent adaptability. Based on field observations in the Upper Yellow River Basin, this study simulated 30 days of waterlogging stress by artificially controlling water levels and analyzed the growth, root anatomy, biomass, photosynthesis, and changes in non-structural carbohydrates (NSC) of C. fungigraminus under root waterlogging (W r group) and above-ground waterlogging (Wa group) conditions. The results showed that the depth and duration of waterlogging significantly ( P < 0.05) reduced the growth characteristics and photosynthetic efficiency of C. fungigraminus . The plant mitigated the stress effectively by loosening cortical cells and forming xylem dissolution-type tissues to enhance oxygen pathways, generating adventitious roots to improve ventilation, increasing the ratio of root-to-shoot, and boosting the soluble sugars, starch, and NSC content in the leaves and underground roots. Under waterlogging conditions, the growth strategies of C. fungigraminus underwent staged changes, initially exhibiting characteristics of the Low-O 2 Escape Strategy (LOES), transitioning to the Low-O 2 Quiescence Strategy (LOQS), and re-exhibiting LOES traits in specific tissues. These adaptive responses confer exceptional tolerance to waterlogging stress, particularly root waterlogging. This study provides scientific evidence for the sustainable development of industrial crops and the ecological restoration of economic forest-grass systems in riparian lake basins, highlighting the potential of C. fungigraminus as a high-quality biological resource. • Waterlogging stress affected Cenchrus fungigraminus growth and photosynthetic traits. • The effects of waterlogging varied substantially with duration and depth. • Above-ground waterlogging had faster and more severe impacts on C. fungigraminus than root waterlogging. • C. fungigraminus showed stronger adaptation to root waterlogging than to above-ground waterlogging. • C. fungigraminus adopted different growth strategies with waterlogging duration and depth.