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| Plano de Ação: | 13.16.04.008.00.03 |
| Descrição: | MATES, A. P. K.; PONTES, N. de C.; HALFELD-VIEIRA, B. A. Bacillus velezensis GF267. Referência: MATES, A. P. K.; PONTES, N. de C.; HALFELD-VIEIRA, B. A. Bacillus velezensis GF267 as a multi-site antagonist for the control of tomato bacterial spot. Biological Control, v. 137, 104013, 2019. 8 p. DOI: https://doi.org/10.1016/j.biocontrol.2019.104013 |
| Parceria/partes: | UFRR - Universidade Federal de Roraima, IF Goiano - Campus Morrinhos, |
| Conteúdo: | Some isolates of sporogenic bacteria can reduce the plant disease intensity through different mechanisms. In the present study, 29 isolates of this group of bacteria were evaluated for the control of tomato bacterial spot in order to select strains with multiple modes of action in disease suppression. In the first experiment, tomato seedlings received three applications of the antagonists on leaves or on soil which were then challenged with Xanthomonas perforans after the second application. There was no effect of the dispensing methods and eight isolates significantly reduced the disease intensity when compared to control. These strains were reassessed for disease control, and characterized based on siderophore production and antibiosis. Eight isolates significantly reduced disease severity in the second in vivo experiment. Among these, strains GF203, GF264, and GF267 inhibited the development of the pathogen in vitro and were able to produce siderophores. Carbon source utilization profile revealed the strain GF267, besides the greatest reduction in the intensity of bacterial spot, presented a reciprocal competition ability with the pathogen. This strain was identified as Bacillus velezensis and, when applied on soil, increased the activity of peroxidase and polyphenoloxidase, provided increment of chlorophyll content, and reduced the disease intensity. Our study demonstrated B. velezensis GF267 as being a multi-site antagonist, which may have potential application in controlling tomato bacterial spot. |
| Observaçao: | (ID_PAT: 24485) |
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| Plano de Ação: | 16.00.2.50.01.16 |
| Descrição: | NECHET, K. de L.; HALFELD-VIEIRA, B. A. Cercospora aff. canescens. Referência: NECHET, K. de L.; HALFELD-VIEIRA, B. A. Development of Cercospora leaf spot on Ipomoea weed species for biological control. Biocontrol, Dordrecht, v. 64, n. 2, p. 185-195, 2019. DOI: https://doi.org/10.1007/s10526-018-09918-w |
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| Conteúdo: | Morning glories (Ipomoea spp.) are important weeds in non-burning sugarcane farming in Brazil, and their chemical control has low efficacy due to the straw mulching. The purpose of this work was to determine the effect of epidemiological parameters on the development of Cercospora leaf spot (Cercospora aff. canescens Ellis & G. Martin) on four Ipomoea weed species, as well as on the host range. The results demonstrated that the use of a suspension of 2 × 107 conidia ml−1 on specific host phenological stages (3–5 leaves, open flowers, and with fruit), with a minimum of a 24 h dew period, induces plant defoliation and a higher disease incidence on Ipomoea nil L. (Roth). However, the same disease incidence and defoliation on I. grandifolia (Dammer) O’Donell, I. quamoclit L., and I. hederifolia L. were not achieved. The pathogen was specific to these four Ipomoea species among 18 plant species. These results represent an important step in the development of a mycoherbicide to control morning glories. |
| Observaçao: | Entrega associada ao projeto encerrado código SEG 03.13.12.002.00.02, vigência 06/2014 a 12/2016. (ID_PAT: 24484) |