Aspectos fisiológicos da germinação de sementes de sucupira-preta (Bowdichia virgilioides Kunth)

Abstract

Bowdichia virgilioides is tree specie with broad dispersion in Brazil, being highly used in refloresting prgrams and recovery of the degraded areas. This specie is suffering a reduction in number in its native habitat, due the desordered commercial exploration. Inaddition to this fact, the seedling formation could be limited based in the germination conditions. This research aimed to study the seed physilogy germination of black sucupira, the seed alterations during the embebition and the factors conditing its germination as dormancy, temperature, light and damage in the seeds. There were used lots of seeds from Ceará, harvested in 2001; Roraima and Minas Gerais, both harvested in 2003. The seed embebition process was evaluated for each 6 hours, observing the morphological and biochemical aspects. For the dormancy overcoming, the treatments were sulfuric acid, sandpaper and hot water. In the germination test was tested the light and temperature effect in black sucupira seeds. The X ray test was used for seed quality evaluation. The seeds of black sucupira has a thiphasic model of embebition and the root protrusion happen around 114 hours, ocorring some modifications in enzymes and proteins resistent to heat during the embebition periods. The seeds of black sucupira have a tegumentar dorrmancy, overcoming with sulfuric acid by 8 and 12 minutes. For the germination test, the constant temperature of 25°C and alternate 20-30°C, allowing a higher percentage and germination speed and absence of light increase the germination speed. In the X ray test the radiation of 30 Kv for 45 seconds allow the best visualization of seeds internal damage and these damages affect the germination.