Morphological and physiological changes in Acer velutinum Boiss seedlings under drought stress

Water is needed for numerous metabolic functions and its loss can modify all characters of plant life. Acer velutinum is a fast-growing species and significant diffuse-porous hardwood in afforestation and reforestation. However, the impact of water stress on A. velutinum has not yet been studied. In this study, the impacts of water deficit on growth, biomass, leaf area, pigment contents, relative water content, free proline, malondialdehyde, superoxide dismutase, and peroxidase activities were studied to describe the morpho-physiological mechanisms related with their drought resistance. One-year Seedlings were exposed to four drought treatments (100, 75, 50, and 25% of the field capacity). The Drought treatments had negative impacts on A. velutinum growth, biomass, and physiological characteristics, as exhibited by decreased plant height, basal diameter, biomass, relative water content, and pigments level, while Proline, MDA concentration, SOD and POD activities multiplied. Drought increased SLA and LAR at mild and moderate treatment, while decreased SLA and LAR at severe treatment, also the growth declining in aboveground biomass was more than the root under severe treatment, so the Root mass ratio (RMR) and Root: Shoot ratio (R/S) expanded. Our data demonstrate that A. velutinum seedlings have the capacity to adapt to water deficit and can develop some experimental advice for velvet maple afforestation and reforestation.