Isolados bacterianos no controle de fitopatógenos in vitro

Abstract

The use of bacteria in the biological control of diseases can reduce environmental contamination caused by the indiscriminate use of chemical fungicides and has been shown to be an effective alternative method for disease control. This study aimed to evaluate the ability of bacterial isolates BAC 1, BAC 2, BAC 3, BAC 4, BAC 5, BAC 6, BAC 7, BAC 8, BAC 9, BAC 10, BAC 11, BAC 12, BAC 13, B.ALF, SB 2084 and MEGA 119 act in the biological control of phytopathogens Rhizoctonia solani, Fusarium udum, Corynespora cassiicola, Sclerotinia sclerotiorum and Sclerotium rolfsii. The experiment was done in vitro, utilizing the pairing method, being 4 repetitions per treatment, made in Petri dish with 9,5 centimeters of diameter, using the culture Potato-Dextrose-Agar (PDA) and incubated in incubator BOD, in dark at 25 ºC ± 2 ºC. The variables analyzed were area under mycelial growth progress curve, mycelial growth, mycelial growth index, percentage growth inhibition and after 21 days of incubation was given a Bell scale score. The isolates BAC 2 and BAC 3 are effective in controlling S. rolfsii in vitro, and the isolates BAC1, BAC 10, B.ALF controlled R. solani. For the phytopathogen S. sclerotiorum, the isolates BAC 1, BAC 3, BAC 4, BAC 8 and BAC 12 showed greater control efficiency. In the antagonism of C. cassiicola, the isolates BAC 1, BAC 4, BAC 5, BAC 11, BAC 13, B.ALF and SB 2084 obtained greater antagonistic potential. It is concluded that the bacteria that stood out in this work for their potential antagonism on most of the phytopathogens tested are the isolates BAC 1, BAC 2 and BAC 3.