Tratamentos pré-germinativos na germinabilidade e no desenvolvimento das plântulas de Bowdichia Virgilioides Kunth. (Fabaceae-Papilionoideae)

Abstract

The specie Bowdichia virgilioides Kunth. (Fabaceae-Papilionoideae) has wide distribution; is common in the savannas of Central Plateau of Brazil and savannas of South America. In this study, it were evaluated the efficiency of pre-germination treatments to overcome seed dormancy and its impact on the development of Bowdichia virgilioides seedlings from different origin and the capacity of absorption of seeds from different sampling years to evaluate the degree of permeability integument. The seeds were collected in 2009, 2010, 2011 and 2012 in areas of Cerrado and Atlantic Forest. The germination experiments were conducted in a completely randomized design with pre-germination methods corresponding to sulfuric acid, cutting and heat treatment, including water immersion and disinfection with sodium hypochlorite with four repetitions of 25 seeds. Seeds were placed on roll paper previously moistened and placed in BOD at 25oC. The character analyzed were percentage of germination of normal seedlings, abnormal seedlings infected and damaged, mortality and what left of hard seeds at the end of the test. Seedlings of this specie have developed root system, with or without secondary roots and cotyledons photosynthesizing. The efficiency of the methods pre-germination depends on the intensity of seed dormancy of Bowdichia virgilioides. Among the methods, seeds subjected to sulfuric acid in 8 minutes are the appropriate procedure for the germination of seeds of the species and the formation of normal seedlings. The perforation followed by water immersion for 24 hours cause mortality of seeds of species due to the low tolerance of fast imbibition. The reduced percentages of abnormal seedlings are infected due to aseptic with sodium hypochlorite before sowing. The seed coat permeability variables present in a sample and between samples with the same dormancy because there are variations of the increase in mass.