Avaliação da qualidade de sementes e mudas de espécies florestais nativas

Abstract

The native forest species seeds are the responsible for the maintenance and perpetuation of those in nature, being for natural germination or by programs of seedlings formation for the forest recomposing. The use of fast tests to evaluate the seeds quality and to supply to the producer or nursery the specify information due to the sowing performance is the great importance in the process of seedlings production. The low germination or emergency percentage of plantules can be a consequence of problems as numbness of the seeds, low energy or due to the low physiologic and sanitary quality. The quality of the seeds is a sum of a series of aspects, among them the sanitary quality assumes fundamental importance. The association of pathogenic microorganisms in the seeds could influence the viability, longevity and the pathogenic transmission to the resulting plant. The present work had been evaluated four native forest species: Schizolobium parahyba (Vell.) S. F. Blake, Enterolobium contortisiliquum (Vell.) Morong, Cedrela fissilis (Vell.) and Sesbania virgata Poir, being justified by the economical and ecological importance that they present and their necessary studies, evaluating the seeds and seedlings quality of these species. The present study had been accomplished with the objective of determining the physiologic and sanitary quality of native forest species seeds, coming from Rio Grande do Sul, Santa Catarina and Paraná, through different tests. The experiments had been accomplished in the Phytosanitary Defense Laboratory and in the Forest Nursery. Germination, energy, and sanity tests had been conducted as well as seedlings evaluation starting from these seeds had been done to evaluate the potential of these ones in the good quality seedlings production. The present study had been showed that the pathogen presence as Aspergillus spp. and Penicillium spp. could cause losses in germination due to the seeds rottenness. The presence of these microorganisms is related to the collection and storage conditions in inadequate form. Fungus of Fusarium and Alternaria gender had been found in the seeds of different origins causing interference in the seedlings quality and consequently they had been reduced the establishment of the plants in the field.