Metodologias para a quebra de dormência em sementes de espécies nativas da Caatinga

Abstract

The Caatinga is a seasonally dry forest whose environmental conditions are cyclical, characterized by seasonal rainfall with a long dry season and high temperatures. Anthropic actions, together with a stressful climate, increase the biome's susceptibility to the desertification process, making ecological restoration measures urgent. The understanding of physiological processes such as the breaking of dormancy of the seeds of the species used is essential for the success of restoration programs, since the germination of the species needs to correspond to the period of greater availability of resources. This study aims to test the presence of dormancy in two species with great potential for the restoration of Caatinga, Ceiba glaziovii (Malvaceae) and Erythrina velutina (Fabaceae) through the five methods for breaking dormancy, which are: physical, chemical and thermal scarification, and soaking in gibberellic acid. Ceiba glaziovii did not show dormancy strategy, considering that the speed and percentage of germination were higher in the control treatment when compared to the other treatments. However, the species Erythrina velutina has physical dormancy, observed by the high speed and percentage of germination when the mechanical scarification treatment was applied, since the species presents a very rigid tegument. Ceiba glaziovii, by not possessing dormancy, allows it to germinate quickly and easily, but without necessarily being in the best conditions for its survival. In an opposite way, Erythrina velutina having dormancy allows several individuals produced by the mother plant to spread their chance of survival over time, since scarification does not occur synchronously between individuals in the natural environment. These germination patterns are relevant to allocate efforts in the correct management of seeds that will be used in restoration programs.