Germination of native seeds from Brazilian subtropical grasslands after storage and temperature shock

Abstract

Studies on storage and thermal shocks allow a better understanding of the physiology of the species and possible inferences about natural regeneration, management or recovery of degraded areas. This study analyzed the influence of high temperatures and storage on germination of native species from Brazilian Grasslands (Eupatorium tanacetifolium, Vernonia flexuosa, Schlechtendalia luzulifolia and Desmanthus tatuhyensis). Seeds stored for 36 months were subjected to 5 treatments (thermal shock of 60°C, 80°C and 100°C, light and dark controls) and kept for 60 days in a germination chamber (12/12 h, 20/30°C) and tetrazolium test was performed with non-germinated seeds. Seeds of all species showed low germination, with no significant difference between controls and heat shock treatments. Storage reduced the percentage of germination of E. tanacetifolium and S. luzulifolia, this one is in the list of extinction threatened species. The other species were not affected by storage, indicating that they can be stored in the experimental condition. The species showed different average time required for germination and germination speed index, with low influence of treatments on these parameters.