Germinação e fungos associados a sementes de ipê amarelo (Handroanthus chrysotrichus - Mart. ex A.DC.) Mattos

Abstract

The genus Handroanthus was created especially for the Brazilian representatives, in which the trees are popularly known as ipê. However, there are factors that affect seed quality, making them unsuitable for seedling production, such as, for example, association with phytopathogenic micro-organisms, which has become an increasing concern, especially in tropical countries. Seeds can harbor and transport microorganisms of all taxonomic groups, pathogenic or not, and therefore the detection of these microorganisms becomes one of the most important tools for the phytosanitary management of diseases. Thus, the objective of this work was to evaluate the germination and to survey the fungi present in the seeds of ipê-amarillo Handroanthus chrysotrichus (Mart. Ex A.DC.) Mattos, collected in the municipality of Itaqui, West Frontier of the State of Rio Grande do Sul. For this, fruit seeds from nine yellow ipê matrices were analyzed. The experimental design was completely randomized, with 4 replicates of 25 seeds. Seed health was evaluated using the Blotter-test method, and each sample was subdivided into two sub-samples, where one was submitted to asepsis with sodium hypochlorite (1%) for three minutes, and the other was not. Twenty five seeds were placed in a gerbox box, on two sheets of germitest paper, previously moistened with distilled water and sterilized until saturation. Then the boxes were conditioned in incubation chambers with temperature between 20 and 22 ° C and the photoperiod of 12 hours, for seven days. For the germination test, the samples were divided into two subsamples, one of them being submitted to asepsis with sodium hypochlorite (1%) for three minutes and the other one not. Twenty - five ipê seeds were conditioned on germitest paper sheets, in gerbox boxes, the substrate being previously moistened with distilled water and sterilized until saturation. Afterwards, the boxes were placed in a germinating chamber BOD, at a temperature of 30 ° C under constant light regime. When evaluating the results, it was observed that there was no significant interaction between plants and asepsis for the evaluation of germination in freshly harvested seeds. The fungi found in the different samples of ile-yellow seeds were: Alternaria alternata, Fusarium spp., Penicillium sp., Aspergillus spp. and Epicoccum sp. It was concluded that the superficial asepsis of the seeds did not interfere in the germination of freshly harvested seeds, however, it reduced the incidence of fungi.