Memória hídrica (stress imprint) em sementes: impacto ecofisiológico na germinação e no crescimento inicial de Sesbania virgata (Cav.) Poir

Abstract

The present study investigated the effects of hydraulic memory on the eco-physiological aspects of germination and the initial development of S. virgata seedlings. Employing a mixed-method approach that combined quantitative and qualitative methods, along with rigorous statistical analysis including tests such as Tukey, ANOVA, and regression analysis, a randomized experiment with various treatments was conducted. Initially, a literature review was conducted to understand the species' importance and the effects of hydraulic memory. Subsequently, laboratory tests were performed to overcome seed dormancy, determine moisture content, and establish the imbibition curve. Additionally, the germination rate of seeds subjected to polyethylene glycol 6000 (PEG 6000) solution was evaluated to simulate water stress, both with seeds that underwent intermittent hydration cycle (IHC) and those that did not undergo this process. Following laboratory analyses, nursery analyses were conducted with two distinct treatments (seeds subjected to IHC and seeds that did not undergo this process), under different watering regimes. Evaluated parameters included shoot height and diameter, root size, dry and fresh weight, Dickson's quality index, biomass allocation, and seedling survival rate. The results indicated the possible presence of hydraulic memory in the seedlings and demonstrated that water deficit negatively affects germination. However, intermittent hydration showed a positive effect on seed germination under water deficit conditions, offering a promising strategy to enhance plant survival in adverse environments.