No abstract

O objetivo do trabalho foi isolar micro-organismos de diferentes nichos e avaliar a capacidade dos mesmos no controle de patógenos invitro (Sclerotinia sclerotiorum e Fusarium solani) e in vivo (S. sclerotiorum), além da promoção do crescimento de Crotalaria sp. Asamostras de solo foram pesadas e diluídas para obtenção dos micro-organismos. Nos testes in vitro, as colônias bacterianas, que apresentaram crescimento, foram submetidas ao confrontamento direto com os fungos fitopatogênicos. Para análise fisiológica das sementes de Crotalaria sp, as sementes foram distribuídas em caixas gerbox contendo papel filtro umedecido com água destilada e incubadas a 20-30 ºC por 10 dias. Também foram testadas a antibiose de escleródios em meio líquido. O delineamento usado foi DIC e os dados foram submetidos à análise de variância e comparados por Tukey a 0,5%. Além disso, foi realizada a patologia de sementes tratadas com as bactérias Fit-03 e Fit-04, além da microbiolização das sementes para avaliação da promoção do crescimento em casa de vegetação. Dos 51 isolados, seis foram capazes de produzir substâncias capazes de inibir o crescimento micelial do F. solani e três de S. sclerotiorum. Na avaliação da capacidade de controle de micro-organismos sobre as sementes das duas espécies de Crotalaria sp, Fit-03 e Fit-04 reduziram a incidência de fungos como Aspergillus e Penicillium. Pode-se afirmar que os isolados Fit-03 e Fit-04 apresentam potencial de uso no controle biológico do mofo branco em plantas de Crotalaria sp., bem como amplo espectro de ação.Palavras-chave: Antibiose. Sclerotinia sclerotiorum. Microbiolização de Sementes.AbstractThe objective was to isolate microorganisms of different niches and assess the ability of these in vitro control pathogens (Sclerotinia sclerotiorum and Fusarium solani) and in vivo (S. sclerotiorum) in addition to promoting the growth of Crotalaria sp. Soil samples were weighed and diluted to obtain the microorganisms. In in vitro tests the bacterial colonies that grew were subjected to direct confrontation with the pathogenic fungi. For physiological seed analysis Crotalaria sp. the seeds were distributed in gerbox boxes containing filter paper moistened with distilled water and incubated at 20-30 ° C for 10 days. Antibiosis sclerotia were also tested in liquid medium. The design used was DIC and the data were subjected to analysis of variance and compared by Tukey 0.5%. In addition, there was the seed pathology treated with the Fit-03 bacteria and Fit-04, in addition to microbiolization seeds for evaluation of growth promotion in greenhouse and also spraying the same in detached leaves of C. junceae and C. spectabillis and pathogen inoculation. After 51 isolates, six were able to produce substances capable of inhibiting the mycelial growth of F. solani and three S. sclerotiorum. In the evaluation of microorganisms control capability on the seeds of the two species of Crotalaria sp, Fit-Fit-03 and 04 reduced the incidence of fungi such as Aspergillus and Penicillium. It can be said that the Fit-03 isolated and Fit-04 have potential use in biological control of white mold in plant Crotalaria sp., as well as a broad spectrum of action.Keywords: Antibiosis. Sclerotinia sclerotiorum. Microbiolization seeds.

Plant growth-promoting rhizobacteria (PGPR) are known to stimulate the biocontrol of phytopathogenic bacteria and fungi, induce plant growth, and increase the yield of important economic crops. In this study, we evaluated in vivo, the ability of Bacillus strains to control soybean white mold disease and promote the growth of soybean plants under greenhouse conditions. Initially, 27 Bacillus strains were analyzed by PCR for the presence of genes encoding antimicrobial molecules, followed by in vitro tests of the positive strains against four phytopathogenic fungi, Sclerotinia sclerotiorum, Macrophomina phaseolina, Rhizoctonia solani, and Colletotrichum truncatum. The bacterial strains that returned positive results for antimicrobial genes were evaluated in vivo for their growth promoting capacity in soybean cultivars Potencia RR and M6210 IPRO, and white mold control in soybean plants. The results showed that eight strains presented the genes bamD, ituD, and fenF, while the bacAB gene was observed in 16 of all tested Bacillus strains. Brie y, the inoculation of the strain VBN02 in increased the fresh biomass of shoots and roots by 111.9% and 79.39% compared with the control. The greenhouse experiment showed that the inoculation of the strain VBN02 was the best treatment for increasing fresh shoot biomass of the soybean M6210 IPRO and Potencia RR cultivar in the single inoculation in relation to the control (111.9% and 103.57%, respectively). Co-inoculation of soybean inoculant and VBE01 was the superior treatment for increasing fresh shoot and root mass in both the cultivars. Two other strains, VBE05 and VBE01, reduced the disease progression of white mold by 39.1% and 37.5%, respectively. In conclusion, our results showed that the Bacillus strains have potential for biocontrol of white mold and for promoting the growth of soybean plants.

Plant growth-promoting rhizobacteria (PGPR) are known to stimulate the biocontrol of phytopathogenic bacteria and fungi, induce plant growth, and increase the yield of important economic crops. In this study, we evaluated in vivo, the ability of Bacillus strains to control soybean white mold disease and promote the growth of soybean plants under greenhouse conditions. Initially, 27 Bacillus strains were analyzed by PCR for the presence of genes encoding antimicrobial molecules, followed by in vitro tests of the positive strains against four phytopathogenic fungi, Sclerotinia sclerotiorum, Macrophomina phaseolina, Rhizoctonia solani, and Colletotrichum truncatum. The bacterial strains that returned positive results for antimicrobial genes were evaluated in vivo for their growth promoting capacity in soybean cultivars Potencia RR and M6210 IPRO, and white mold control in soybean plants. The results showed that eight strains presented the genes bamD, ituD, and fenF, while the bacAB gene was observed in 16 of all tested Bacillus strains. Briefly, the inoculation of the strain VBN02 in increased the fresh biomass of shoots and roots by 111.9% and 79.39% compared with the control. The greenhouse experiment showed that the inoculation of the strain VBN02 was the best treatment for increasing fresh shoot biomass of the soybean M6210 IPRO and Potencia RR cultivar in the single inoculation in relation to the control (111.9% and 103.57%, respectively). Co-inoculation of soybean inoculant and VBE01 was the superior treatment for increasing fresh shoot and root mass in both the cultivars. Two other strains, VBE05 and VBE01, reduced the disease progression of white mold by 39.1% and 37.5%, respectively. In conclusion, our results showed that the Bacillus strains have potential for biocontrol of white mold and for promoting the growth of soybean plants.