Alterações fisiológicas nas sementes armezenadas de Butia capitata e seus impactos na germinação de embriões cultivados in vitro

Abstract

Seed storage can lead to both dormancy breaking and seed deterioration. However, this topic remains understudied in tropical species. We evaluated physiological changes in seeds of Butia capitata (a native fruit species of the Brazilian Cerrado) over time under different storage conditions. Freshly dispersed pyrenes (endocarp+seed) of B. capitata were stored in shade and monitored for 150 days for water content, germination, emergence speed index (ESI), malondialdehyde (MDA) content, electrical conductivity (EC), and operculum resistance. In another study, pyrenes stored in sand, shade, and refrigeration for 270 days had their embryos excised, cultured in vitro, and evaluated for cotyledonary petiole elongation, sheath emission, and root development. Water content decreased throughout storage until stabilization after 120 days. Germination rate, emergence speed index (ESI), and operculum resistance remained stable until 90 days, showing significant reduction at 120 and 150 days. Conversely, malondialdehyde (MDA) content and electrical conductivity (EC) increased over time, particularly after 90 days of seed storage. Refrigerated storage promoted significantly greater elongation rates compared to other treatments, enabling over 75% of embryos to exhibit petiole growth after 210 days of storage. Sheath emission and root development were reduced during the storage period, particularly after 90 days, regardless of storage conditions. Storage promoted dormancy reduction in B. capitata seeds but simultaneously decreased viability and vigor, particularly after 90 days of storage. While refrigeration extended seed longevity, it reduced sheath emission and root development capacity during in vitro cultivation.