Potential worldwide distribution of Fusarium dry root rot in common beans based on the optimal environment for disease occurrence.

Root rots are a constraint for staple food crops and a long-lasting food security problem worldwide. In common beans, yield losses originating from root damage are frequently attributed to dry root rot, a disease caused by the Fusarium solani species complex. The aim of this study was to model the current potential distribution of common bean dry root rot on a global scale and to project changes based on future expectations of climate change. Our approach used a spatial proxy of the field disease occurrence, instead of solely the pathogen distribution. We modeled the pathogen environmental requirements in locations where in-situ inoculum density seems ideal for disease manifestation. A dataset of 2,311 soil samples from commercial farms assessed from 2002 to 2015 allowed us to evaluate the environmental conditions associated with the pathogen's optimum inoculum density for disease occurrence, using a lower threshold as a spatial proxy. We encompassed not only the optimal conditions for disease occurrence but also the optimal pathogen's density required for host infection. An intermediate inoculum density of the pathogen was the best disease proxy, suggesting density-dependent mechanisms on host infection. We found a strong convergence on the environmental requirements of both the host and the disease development in tropical areas, mostly in Brazil, Central America, and African countries. Precipitation and temperature variables were important for explaining the disease occurrence (from 17.63% to 43.84%). Climate change will probably move the disease toward cooler regions, which in Brazil are more representative of small-scale farming, although an overall shrink in total area (from 48% to 49% in 2050 and 26% to 41% in 2070) was also predicted. Understanding pathogen distribution and disease risks in an evolutionary context will therefore support breeding for resistance programs and strategies for dry root rot management in common beans

Characterization of adaptability components of Brazilian isolates of Macrophomina pseudophaseolina

"This is the peer reviewed version of the following article: Negreiros, Andréia Mitsa Paiva, Naama Jéssica de Assis Melo, Hohana Lissa de Sousa Medeiros, Fernando Henrique Alves Silva, Josep Armengol, and Rui Sales Júnior. 2020. "Characterization of Adaptability Components of Brazilian Isolates of Macrophomina Pseudophaseolina". Journal of Phytopathology 168 (7-8). Wiley: 490-99. doi:10.1111/jph.12927. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] Macrophomina pseudophaseolina is a new Macrophomina species reported on different crop and weed species in Brazil, India and Senegal, but to date there are no studies about its adaptability components. In this work, a collection of 62 M. pseudophaseolina isolates obtained from roots of the weed species Trianthema portulacastrum and Boerhavia diffusa collected in Northeastern Brazil, was used to: (a) study the effect of temperature and salinity on mycelial growth, (b) to determine their sensitivity to the fungicide carbendazim and (c) to assess their aggressiveness on melon and watermelon seedlings. Results showed variability among M. pseudophaseolina isolates. The optimum temperature for mycelial growth ranged between 26.4 and 38.1oC. NaCl reduced the in vitro growth of all isolates, which were also highly sensitive to the fungicide carbendazim, exhibiting EC50 values ranging from 0.013 to 0.089 mg/L a.i. Disease severity values on melon and watermelon seedlings showed that M. pseudophaseolina isolates were more aggressive in melon than in watermelon. Information about adaptability components of M. pseudophaseolina obtained in this study could be incorporated on breeding programs for melon and watermelon crops.This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil (CAPES) - Finance Code 001 and by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).Paiva Negreiros, AM.; Melo, N.; De Soussa Medeiros, H.; Alves Silva, F.; Armengol Fortí, J.; Sales Junior, R. (2020). Characterization of adaptability components of Brazilian isolates of Macrophomina pseudophaseolina. Journal of Phytopathology. 168(7-8):490-499. https://doi.org/10.1111/jph.12927S4904991687-8Ambrósio, M. M. Q., Dantas, A. C. A., Martínez-Perez, E., Medeiros, A. C., Nunes, G. H. S., & Picó, M. B. (2015). Screening a variable germplasm collection of Cucumis melo L. for seedling resistance to Macrophomina phaseolina. Euphytica, 206(2), 287-300. doi:10.1007/s10681-015-1452-xBrito, A. C. de Q., de Mello, J. F., Michereff, S. J., de Souza-Motta, C. M., & Machado, A. R. (2019). First report of Macrophomina pseudophaseolina causing stem dry rot in cassava in Brazil. Journal of Plant Pathology, 101(4), 1245-1245. doi:10.1007/s42161-019-00309-3Cervantes-Garcia, D., Saul Padilla-Ramirez, J., Simpson, J., & Mayek-Perez, N. (2003). Osmotic Potential Effects on In Vitro Growth, Morphology and Pathogenicity of Macrophomina phaseolina. Journal of Phytopathology, 151(7-8), 456-462. doi:10.1046/j.1439-0434.2003.00751.xFerreira, D. F. (2011). Sisvar: a computer statistical analysis system. Ciência e Agrotecnologia, 35(6), 1039-1042. doi:10.1590/s1413-70542011000600001Gupta, G. K., Sharma, S. K., & Ramteke, R. (2012). Biology, Epidemiology and Management of the Pathogenic Fungus Macrophomina phaseolina (Tassi) Goid with Special Reference to Charcoal Rot of Soybean (Glycine max (L.) Merrill). Journal of Phytopathology, 160(4), 167-180. doi:10.1111/j.1439-0434.2012.01884.xLannou, C. (2012). Variation and Selection of Quantitative Traits in Plant Pathogens. Annual Review of Phytopathology, 50(1), 319-338. doi:10.1146/annurev-phyto-081211-173031Machado, A. R., Pinho, D. B., Soares, D. J., Gomes, A. A. M., & Pereira, O. L. (2018). Bayesian analyses of five gene regions reveal a new phylogenetic species of Macrophomina associated with charcoal rot on oilseed crops in Brazil. European Journal of Plant Pathology, 153(1), 89-100. doi:10.1007/s10658-018-1545-1Mastan, A., Bharadwaj, R., Kushwaha, R. K., & Vivek Babu, C. S. (2019). Functional Fungal Endophytes in Coleus forskohlii Regulate Labdane Diterpene Biosynthesis for Elevated Forskolin Accumulation in Roots. Microbial Ecology, 78(4), 914-926. doi:10.1007/s00248-019-01376-wMedeiros, A. C., Melo, D. R. M. de, Ambrósio, M. M. de Q., Nunes, G. H. de S., & Costa, J. M. da. (2015). Métodos de inoculação de Rhizoctonia solani e Macrophomina phaseolina em meloeiro (Cucumis melo). Summa Phytopathologica, 41(4), 281-286. doi:10.1590/0100-5405/2083Mbaye, N., Mame, P. S., Ndiaga, C., & Ibrahima, N. (2015). Is the recently described Macrophomina pseudophaseolina pathogenically different from Macrophomina phaseolina? African Journal of Microbiology Research, 9(45), 2232-2238. doi:10.5897/ajmr2015.7742Negreiros, A. M. P., Sales Júnior, R., León, M., Melo, N. J., Michereff, S. J., Ambrósio, M. M., … Armengol, J. (2019). Identification and pathogenicity of Macrophomina species collected from weeds in melon fields in Northeastern Brazil. Journal of Phytopathology, 167(6), 326-337. doi:10.1111/jph.12801Francisco, de A. S. e S., & Carlos, A. V. de A. (2016). The Assistat Software Version 7.7 and its use in the analysis of experimental data. African Journal of Agricultural Research, 11(39), 3733-3740. doi:10.5897/ajar2016.11522Tonin, R. F. B., Avozani, A., Danelli, A. L. D., Reis, E. M., Zoldan, S. M., & Garcés-Fiallos, F. R. (2013). In vitro mycelial sensitivity of Macrophomina phaseolina to fungicides. Pesquisa Agropecuária Tropical, 43(4), 460-466. doi:10.1590/s1983-40632013000400014Wrather, J. A., Anderson, T. R., Arsyad, D. M., Tan, Y., Ploper, L. D., Porta-Puglia, A., … Yorinori, J. T. (2001). Soybean disease loss estimates for the top ten soybean-producing counries in 1998. Canadian Journal of Plant Pathology, 23(2), 115-121. doi:10.1080/07060660109506918Zhan, J., & McDonald, B. A. (2013). Experimental Measures of Pathogen Competition and Relative Fitness. Annual Review of Phytopathology, 51(1), 131-153. doi:10.1146/annurev-phyto-082712-102302Zhao, L., Cai, J., He, W., & Zhang, Y. (2019). Macrophomina vaccinii sp. nov. causing blueberry stem blight in China. MycoKeys, 55, 1-14. doi:10.3897/mycokeys.55.3501

Produtividade e estabilidade de pastagens biodiversas ricas em leguminosas no Acre.

Apesar de pouco pesquisadas no Brasil, pastagens plantadas diversificadas têm se tornado comuns na pecuária do Acre. Este trabalho objetivou avaliar, em escala comercial, a produtividade e a estabilidade de uma pastagem biodiversa rica em leguminosas em solo com drenagem imperfeita em Rio Branco, AC. A pastagem foi formada originalmente na década de 1980 e diversificada com plantio de forrageiras estoloníferas entre 1998 e 2002, sendo composta atualmente por quatro gramíneas e três leguminosas. A dinâmica da composição botânica do pasto foi avaliada no ciclo 1 (2012 a 2014) e no ciclo 2 (2018 a 2020) e a produtividade animal no ciclo 2. Apesar da variação sazonal em sua composição nos dois ciclos de avaliação, o estudo mostrou que o pasto biodiverso já havia alcançado a relação gramínea-leguminosa desejada durante o primeiro ciclo, com aproximadamente um terço de leguminosas e dois terços de gramíneas. Essa harmonia se manteve no segundo ciclo, sugerindo estabilidade em longo prazo. Além disso, a pastagem manteve-se produtiva após mais de 20 anos, com capacidade de suporte anual variando de 2,8 a 3,0 unidades animais por hectare e produtividade anual de 642 kg/ha a 729 kg/ha de peso vivo. Conclui-se que pasto biodiverso rico em leguminosas é excelente alternativa para formação de pastagens produtivas e longevas em solos com drenagem imperfeita no Acre. Esta publicação está de acordo com os Objetivos de Desenvolvimento Sustentável 2 (Fome Zero e Agricultura Sustentável), 12 (Consumo e Produção Responsáveis) e 13 (Ação contra a Mudança Global do Clima). Os Objetivos de Desenvolvimento Sustentável (ODS) são uma coleção de 17 metas globais estabelecidas pela Assembleia Geral das Nações Unidas e que têm o apoio da Embrapa para que sejam atingidas.Selo ODS 2; Selo ODS 12; Selo ODS 13

Validation of two real-time PCRs targeting the PE-PGRS 20 gene and the region of difference 4 for the characterization of Mycobacterium bovis isolates.

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Cadastro ambiental rural e inscrição dos campos experimentais da Embrapa Tabuleiros Costeiros, Sergipe.

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