FUNGOS ENDOFÍTICOS DE PLANTAS DANINHAS NO CONTROLE DA MANCHA MARROM DO TRIGO

Abstract

Due to the great importance of wheat, the search for reducing the effects of its diseases is needed, with the lowest environmental impact possible. In several parts of continents, spot blotch, caused by Bipolaris sorokiniana (Sacc), is known as a great adversity for that cropsince it leads to a remarkable decrease in production. Plants tend to defend themselves based on mechanisms of resistance to pathogens, which lie dormant so that plants are activated only after being exposed to elicitor agents or pathogens. Thus, the present study aimed to isolate endophytic fungi, select and test possible resistance inducers against B. sorokinianain wheatunder greenhouse and field conditions. We isolated 11 endophytic fungishowing antagonist activity andability to accumulate phytoalexins in plants. Of these fungi, two were selected and molecularly identified as Aspergillus japonicas and Trichoderma tomentosum, isolated from harmful plants. In experiments conducted in the field in 2015 and 2016, in Guarapuava and Boa Ventura de São Roque-PR, we found that the suspensions of endophytic fungi were able to promote differences in yield, number of ears, number of grains and height of plants. And were also able to increase the activity of the enzymes, both PR proteins, chitinase, β 1,3-glucanase and peroxidase, as well as antioxidant compounds such as catalase, phenylalanine ammonia lyase, polyphenoloxidases, superoxide dismutase, ascorbate peroxidase, glutathione peroxidase, glutamine reductase, glutathione S-transfernase, flavonoids and phenolic compounds, when compared with the control. The suspensions of endophytic fungi, especially T. Tomentosum, have the potential to be used in the cultivation of wheat as disease control agents, since they have reduced the severity of the brown spot.