Influência de formas do relevo em atributos físicos de um latossolo sob cultivo de cana-de-açúcar Influence of the relief forms on physical attributes of an oxisol cropped with sugarcane

Os atributos físicos do solo variam em função das formas do relevo e sofrem influência da mineralogia da fração argila e do manejo da cultura de cana-de-açúcar, podendo interferir no processo de compactação do solo. Este trabalho foi realizado com o objetivo de avaliar o estado dos atributos físicos em diferentes formas do relevo em um Latossolo Vermelho eutroférrico argiloso sob cultivo de cana-de-açúcar. A área apresenta duas formas de relevo: uma côncava, que ocorre nas posições mais elevadas, e uma linear, constituída pelos segmentos ombro, escarpa, meia encosta e encosta inferior. As amostras de solo foram coletadas durante o ciclo da cultura, nas camadas de 0,00-0,15m, 0,15-0,30m e 0,30-0,45m, para determinação do teor de matéria orgânica e dos seguintes atributos físicos: densidade do solo, porosidade total, macroporosidade, microporosidade, resistência do solo à penetração e teor de água no solo. A mineralogia mais gibbsítica e o maior teor de matéria orgânica, encontrada na forma de relevo côncava e de segmento ombro, proporciona menores valores de densidade do solo, de resistência do solo à penetração e de microporosidade e maiores valores de macroporosidade e de porosidade total do que a mineralogia mais caulinítica, encontrada nos demais segmentos da forma linear.<br>The physical attributes of the soil vary according to the relief forms and suffer from the mineralogy of the clay fraction and the management of the sugarcane culture, being able to influence the soil compaction process. This research was developed in Jaboticabal-SP, aiming at evaluating the behavior of physical attributes in different relief forms in an oxisol cropped with sugarcane. The area presents two relief forms (concave and linear), the concave one, that occurs at the highest positions, and the linear one, consisting of shoulder, scarp, stocking lean and inferior lean segments. The samples soil were collected during the sugarcane cycle, in the 0.00-0.15, 0.15-0.30 and 0.30-0.45m layers, for the determination of the organic matter and the following physical attributes: bulk density, total porosity, macro and microporosity, soil penetration resistance and soil moisture. The mineralogy most gibbsitic and the greatest value of organic matter, found in the concave relief form and in the shoulder segment, provide lower bulk density, soil penetration resistance and microporosity values and higher macroporosity and total porosity values when compared with the other segments of the linear form (caulinitic mineralogy)

Assessment of genotoxicity and cytotoxicity of "lixeira" (Curatella americanaL.) &#955; using the prophage induction test (SOS inductest)

Curatella americana L., commonly known as "lixeira" in Brazil, has been used in folk medicine to treat ulcers and inflammations. The purpose of the present work was to evaluate the cytotoxic and genotoxic potential of the ethanolic extract of C. americana stem bark using the prophage &#955; induction test (SOS inductest). To evaluate the cytotoxicity of this plant, after treatment with different concentrations of the extract, Escherichia coli WP2s(&#955;) cultures were diluted in M9 buffer, inoculated into LB plates, and incubated for 24 h at 37 °C. To assess genotoxicity, the lysogenic strain E. coli WP2s(&#955;) was treated with different concentrations of the extract. Then, the lysogenic strain was added to the indicator strain (RJF013), LB(1/2)(malt/amp), seeded into plates with the matches, and incubated for 24 h at 37 °C. After this period, the total number of colonies and the number of plaques were counted to evaluate C. americana cytotoxicity and genotoxicity, respectively. Our results showed that although the extract of "lixeira" did not modify the survival of bacteria (p > 0.05), it caused a significant increase in prophage &#955; induction, especially at the higher concentrations (p<0.05). Therefore, we conclude that the ethanolic extract of C. americana stem bark did not present cytotoxic effect, but some genotoxic potential was observed.<br>Curatella americana L., comumente conhecida como "lixeira" no Brasil, é utilizada em medicina popular para tratamento de úlceras e inflamações. O presente trabalho teve como objetivo avaliar o potencial citotóxico e genotóxico do extrato etanólico das cascas de C. americana utilizando o Induteste SOS. Para avaliar a citotoxicidade da planta, depois de tratadas com diferentes concentrações do extrato, culturas de E. coli WP2s(&#955;) foram dilu&#957;das em tampão M9 e semeadas em placas LB. Para avaliar a genotoxicidade da planta, a cepa lisogênica WP2s(&#955;) de E. coli foi tratada com diferentes concentrações do extrato. Em seguida, esta foi adicionada à cepa indicadora (RJF013) e ambas foram semeadas em placas em meio LB(1/2)(malt)(amp). Todas as culturas foram incubadas por 24 h a 37 °C. Posteriormente, o número total de colônias e o número de centros infecciosos foram computados para a avaliação da citotoxidade e da genotoxicidade desta planta, respectivamente. Os resultados mostraram que embora o extrato de C. americana não tenha modificado a sobrevivência bacteriana (p > 0,05), provocou aumento significativo (p < 0,05) na indução do profago &#955;, especialmente nas concentrações mais altas. Assim, concluiu-se que o extrato etanólico das cascas de C. americana não apresentou atividade citotóxica, mas foi observada ação genotóxica direta

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora