RESUMO
Nodule cultures are formed through an intermediate morphogenetic route that lies between organogenesis and somatic embryogenesis. Although well described in many species, different aspects of the morphological and histological development of nodules remain to be clarified. Based on their threatened status and high ornamental value, Billbergia alfonsi-joannis and Billbergia zebrina, two epiphytic bromeliad species endemic to the South American Atlantic Forest, were studied. Nodular cultures were induced to grow from nodal segments taken from etiolated seedlings grown in vitro for 12 weeks in the dark on MS medium supplemented with 1 µM TDZ. Samples were taken for analysis weekly over 8 weeks of growth and analyzed under light, transmission electron, and scanning electron microscopes. Morphological and histological analysis showed that nodular clusters originated from stem pericycles and consisted of a polycenter, cambial tissue, cortical parenchyma, and a covering tissue. The polycenter consisted of an organizational center dispersed in parenchymal tissue. Each organizational center was formed by a vascular system surrounded by a bundle sheath. A cambial tissue surrounded these polycenters, promoting the regeneration of new nodules and leading to the formation of buds and roots. Primary nodules could generate secondary nodules in a repetitive process. Thus, histological analysis revealed the origin and formation of nodular cultures. These new data will support the establishment of micropropagation protocols and regeneration on a large scale for these species.
Assuntos
Bromeliaceae/anatomia & histologia , Bromeliaceae/citologia , Diferenciação Celular , Técnicas de Cultura de Tecidos/métodos , Bromeliaceae/ultraestrutura , Modelos Biológicos , Especificidade da EspécieRESUMO
Sturnira lilium was colected from December 2006 to May 2009, in remainder of restinga vegetation in Santa Catarina state. In three opportunities we observed the presence of seeds of Billbergia zebrina in feces of S. lilium. The fruits of Bromeliaceae are rare as part of the diet of bats in the Neotropical area. This is the first record of B. zebrine in the diet of S. lilium.
Durante as amostragens de morcegos que ocorreram de dezembro de 2006 a maio de 2009, em remanescente de vegetação de restinga sul de Santa Catarina, em três oportunidades foi observada a presença de sementes de Billbergia zebrina em fezes de indivíduos de Sturnira lilium. O registro de utilização de frutos de bromeliáceas como parte da dieta de morcegos frugívoros na região Neotropical é raro. Este é o primeiro registro de consumo de frutos B. zebrina por S. lilium.
RESUMO
Sturnira lilium was colected from December 2006 to May 2009, in remainder of restinga vegetation in Santa Catarina state. In three opportunities we observed the presence of seeds of Billbergia zebrina in feces of S. lilium. The fruits of Bromeliaceae are rare as part of the diet of bats in the Neotropical area. This is the first record of B. zebrine in the diet of S. lilium.
Durante as amostragens de morcegos que ocorreram de dezembro de 2006 a maio de 2009, em remanescente de vegetação de restinga sul de Santa Catarina, em três oportunidades foi observada a presença de sementes de Billbergia zebrina em fezes de indivíduos de Sturnira lilium. O registro de utilização de frutos de bromeliáceas como parte da dieta de morcegos frugívoros na região Neotropical é raro. Este é o primeiro registro de consumo de frutos B. zebrina por S. lilium.