Efeito do condicionamento fisiológico na tolerância ao déficit hídrico e nas características morfofisiológicas de sementes de Solanum paniculatum L.

Abstract

Priming is a pre-germinative treatment used in crop seeds with the aim to accelerate and allow uniform germination. It is know that priming induces membrane and macromolecules repair, expression of genes linked to different stresses, enhanced the oxidant systems, among other improvements. Thus, the aim in this work was to induce tolerance to water deficit and perform a morphophysiological and cytological studies in Solanum paniculatum seeds. During priming treatment the seeds were placed in tubes containing polyethylene glycol (PEG) 8000 solutions with potential of 0.0, -0.4, -0.8. -1.0, -1.2 and -1.4 MPa and no primed seeds (NC), incubated at 15°C during 15 days under continuous light. The water deficit simulation was performed with in the presence of a substratum containing PEG 8000 solutions at the potential of 0.0, -0.2, -0.4, -0.6, -0.8 and -1.0 MPa at 25°C under continuous light. It was observed that priming in the potentials of 0.0 (hydropriming), -0.8, -1.0, -1.2 and -1.4 MPa (osmoprimig) increased the final germination percentage in water deficit at -0.4 MPa as compared with control (NC). However, normal seedlings were observed in the treatments with -1.0 and -1.2 MPa. Therefore, -1.0 MPa was used for morphohysiological and cytological studies before, during and after priming. Thus, we found a significant reduction in the sugar content of sucrose, raffinose, stachyose and fructose during priming. After priming, the main changes were: formation of empty areas in the micropylar region and increased intercellular space. There were also reduction in number and size of lipid bodies and increased content of protein and amyloplast