Transmissibilidade de Sclerotinia sclerotiorum via semente de canola

Abstract

This monograph aimed to evaluate the transferability of the S. sclerotiorum pathogen via canola seed. There are several forms of dissemination of S. sclerotiorum, being one of these the transmission via the seed responsible for the low germination index, evoking failures in the canola cultivation areas, one of the main oilseed species used in the production of biofuels, becoming a bounding factor to the production. The seeds that germinate, transmit the pathogen to the plant, which presents symptoms of the disease. The experiment was carried out in a conditioning room of the Laboratory of Microbiology and Phytopathology from the Federal University of Grande Dourados (UFGD). The treatments were: exposure to the fungal mycelium for 10, 20, 30 hours and sample. After the inoculation, the percentage of emergence and percentage of seedlings with symptoms were evaluated. Asymptomatic, symptomatic and non-germinated seeds of each plot were collected. These were washed, submitted to asepsis and the plant fragments, as well as the seeds, were plated in Neon S medium. The plates were incubated at 25°C in the constant dark, and the readings performed at the seventh and twelfth days of incubation, observing the formation of mycelium and the medium's coloring shift. The 10 hours treatment did not differ statistically from the sample, both had good germination and emergence indexes with regard to the other treatments. The 20 and 30 hours treatment obtained lower germination. The Neon-S test proved the transferability of S. sclerotiorum via inoculated seeds to the canola crops. The seed-associated S. sclerotiorum pathogen reduces the percentage of germination and emergence of the canola crop.