Diversity of fungi in seeds of hymenaea stignocarpa and hymenaea courbaril before and after fungicide treatments

Abstract

The recovery of degraded areas led to an increase of native forest seedlings production. Jatoba-do-cerrado (Hymenaea stignocarpa Mart.) and jatoba-da-mata (Hymenaea courbaril L.), native species of the Brazilian Cerrado, are widely used for the recovery of this biome. Although forest species present a diversity of pathogens disseminated by seeds, few studies have been published and no study was found for jatoba. Because the seed is one of the main forms of pathogen dissemination, the aim of our work was to evaluate the natural incidence of fungi in seed lots of jatoba-do-cerrado and jatoba-da-mata and the performance of different fungicides for seed treatment recommendation. The experiment was carried out at the Genetics and Biotechnology Laboratory of the University Center of Patos de Minas. Two chemical treatments were submitted in the seeds and then divided into seven replicates of 15 seeds for each species. The first treatment was with the active principle thiophanate-methyl and fluazine, commercial name Certeza^®, in the dose of 145 mL of the product in 100 kg of seeds. The second treatment was with fludioxonil, commercial name Maxim^® XL, in the dose of 100 mL of the product in 100 kg of seeds. There was a third treatment corresponded to the control (without seed treatment). The visual analyzes were performed after eight days on each seed with a magnifier to verify the presence of developing fungal colonies. The growth fungi fructifications were observed using a stereomicroscope. The found fungi species were: Aspergillus sp., Fusarium sp., Mucor sp., Penicillium sp., Pestalotiopsis sp., Phomopsis sp., Rhizoctonia sp., Rhizopus sp. and Trichoderma sp. It occurred interaction between seed treatment and species for Aspergillus sp., Fusarium sp., Mucor sp., Phomopsis sp., Rhizoctonia sp. and Trichoderma sp. For Penicillium sp., Pestalotiopsis sp. and Rhizopus sp., only the isolated factors were significant. Jatoba-do-cerrado seeds had a higher incidence than jatoba-da-mata seeds in all the found fungi. Certeza^® and Maxim^® XL have potential in seed treatment for the species. The fungicide Certeza^® was more efficient to control the pathogenic fungi in seed treatment.