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

Abstract

The yellow ipê is a native tree of South America belonging to the family Bignoniaceae. In Brazil it is one of the preferred tree species for urban and rural afforestation due to its beauty and rusticity. Due to its popularization, propagation and storage methods have been studied to improve its dissemination and planting. Therefore, the objective of this study was to evaluate the germination and the presence of fungi associated with yellow ipê seeds (Handroanthus chrysotrichus (Mart. ex A.DC.) Mattos.), after 14 months of storage, submitted or not to asepsis. The seeds used belong to eight matrices of the municipality of Itaqui. They were stored in the Phytopathology Laboratory of the Federal University of Pampa, Itaqui Campus, in bags of kraft paper kept in refrigeration. The experimental design used was the one entirely randomized, arranged in factor scheme 8 x 2, with five repetitions of 25 seeds. The germination test was divided into two subsamples, one submitted to asepsis with sodium hypochlorite (1%) for three minutes and the other not. Each repetition with 25 seeds was packed in gerbox boxes under sheets of Germitest© paper, previously moistened with distilled water and sterilized until saturation. Later, the gerbox were packaged in BOD, with temperature 30°C, under constant light regime for 15 days. The sanity test was performed by the Blotter-test method, where each sample was subdivided into two subsamples, and one underwent asepsis with sodium hypochlorite (1%) for three minutes and the other was not. Each repetition with 25 seeds was packed in gerbox boxes under sheets of Germitest© paper, previously moistened with distilled water and sterilized until saturation. The gerbox were packaged in BOD, with a temperature of 20°C and a photoperiod of 12 hours, for seven days. The germination and vigor of the ipê-yellow seeds remained stable even after 14 months of refrigerated storage. The fungi Alternaria sp., Epicoccum sp., Phoma sp., Aspergillus spp., Fusarium sp., Nigrospora sp., Penicillium spp., Drechslera sp. and Curvularia sp. were identified in the different matrix of yellow ipê seeds. It is concluded that germination was maintained after 14 months of storage. Superficial asepsis with sodium hypochlorite (1%) during three minutes did not interfere in the germination of yellow ipê seeds and reduced the incidence of infesting fungi.