Adaptabilidade e estabilidade de populações de milho-pipoca relacionadas por ciclos de seleção

Os objetivos deste trabalho foram estimar os parâmetros de adaptabilidade e estabilidade em populações de milho-pipoca relacionadas por ciclos de seleção, inferir sobre a eficiência dos métodos de seleção pelos quais as populações foram obtidas e avaliar os efeitos da seleção sobre os parâmetros de adaptabilidade e estabilidade. Vinte e cinco populações e três testemunhas comerciais foram avaliadas em 14 ensaios realizados nos anos agrícolas de 2003/2004, 2004/2005, 2006/2007, 2008/2009 e 2009/2010, em sete locais. Utilizou-se o delineamento experimental de blocos completos ao acaso, com quatro repetições. Foram analisadas a capacidade de expansão, avaliada em forno de microondas e na pipocadora Metric Weight Volume Tester (MWVT), além da produtividade de grãos. Utilizou-se o método de adaptabilidade e estabilidade de Eberhart & Russell. Em geral, as populações base e melhoradas apresentaram previsibilidade de comportamento em resposta às variações de ambiente. A seleção pode provocar mudanças nos padrões de adaptabilidade e estabilidade, e as diferentes estratégias de seleção empregadas na obtenção das populações apresentaram eficiências semelhante

Fusarium: more than a node or a foot-shaped basal cell

Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid genera (www.fusarium.org)

Can land use changes alter carbon, nitrogen and major ion transport in subtropical brazilian streams? Modificações no uso da terra podem alterar o transporte fluvial de carbono, nitrogênio e íons maiores?

Several studies in tropical watersheds have evaluated the impact of urbanization and agricultural practices on water quality. In Brazil, savannas (known regionally as Cerrados) represent 23% of the country's surface, representing an important share to the national primary growth product, especially due to intense agriculture. The purpose of this study is to present a comprehensive evaluation, on a yearly basis, of carbon, nitrogen and major ion fluxes in streams crossing areas under different land use (natural vegetation, sugar cane and eucalyptus) in a savanna region of SE Brazil. Eucalyptus and sugar cane alter the transport of the investigated elements in small watersheds. The highest concentration of all parameters (abiotic parameters, ions, dissolved organic carbon DOC - and dissolved inorganic carbon - DIC) were found in Sugar Cane Watersheds (SCW). The observed concentrations of major cations in Eucalyptus Watersheds (EW) (Mg, Ca, K, Na), as well as DIN and DOC, were found frequently to be intermediate values between those of Savanna Watersheds (SW) and SCW, suggesting a moderate impact of eucalyptus plantations on the streamwater. Same trends were found in relation to ion and nutrient fluxes, where the higher values corresponded to SCW. It is suggested that sugar cane plantations might be playing an important role in altering the chemistry of water bodies.<br>Diversos estudos têm sido desenvolvidos em bacias de drenagem tropicais no intuito de avaliar o impacto da urbanização e das práticas agrícolas na qualidade dos corpos d'água. No Brasil, as savanas (conhecidas regionalmente como Cerrado) representam 23% do território brasileiro, sendo uma região importante no crescimento nacional, especialmente devido às intensas atividades agrícolas. A finalidade deste trabalho é apresentar uma avaliação dos fluxos de carbono, nitrogênio e principais íons em córregos com diferentes usos do solo (vegetação, cana de açúcar e eucalipto) em uma região de Cerrado, SE Brasil. A cana de açúcar e o eucalipto alteram o transporte dos elementos investigados nessas pequenas bacias de drenagem. As concentrações mais elevadas de todos os parâmetros analisados (parâmetros abióticos, íons, carbono orgânico dissolvido e carbono inorgânico dissolvido) foram encontradas na bacia de cana de açúcar (SCW). As concentrações observadas para os cátions na bacia do eucalipto (EW) (Mg, Ca, K, Na), assim como Carbono Inorgânico Dissolvido (CID) e Carbono Orgânico Dissolvido (COD), apresentaram valores intermediários entre as bacias do Cerrado e da cana de açúcar, sugerindo um impacto moderado dessa plantação aos corpos d'água. Mesma tendência foi observada para os fluxos de íons e nutrientes, sendo, novamente, os maiores valores encontrados na bacia de cana-de-açúcar. Os autores sugerem que o cultivo da cana de açúcar representa um importante fator na modificação da química de pequenas bacias de drenagem

Fusarium and allied fusarioid taxa (FUSA). 1

Seven Fusarium species complexes are treated, namely F. aywerte species complex (FASC) (two species), F. buharicum species complex (FBSC) (five species), F. burgessii species complex (FBURSC) (three species), F. camptoceras species complex (FCAMSC) (three species), F. chlamydosporum species complex (FCSC) (eight species), F. citricola species complex (FCCSC) (five species) and the F. concolor species complex (FCOSC) (four species). New species include Fusicolla elongata from soil (Zimbabwe), and Neocosmospora geoasparagicola from soil associated with Asparagus officinalis (Netherlands). New combinations include Neocosmospora akasia, N. awan, N. drepaniformis, N. duplosperma, N. geoasparagicola, N. mekan, N. papillata, N. variasi and N. warna. Newly validated taxa include Longinectria gen. nov., L. lagenoides, L. verticilliforme, Fusicolla gigas and Fusicolla guangxiensis. Furthermore, Fusarium rosicola is reduced to synonymy under N. brevis. Finally, the genome assemblies of Fusicolla betae (CBS 175.32), Microcera coccophila (CBS 310.34), Rectifusarium robinianum (CBS 430.91), Rugonectria rugulosa (CBS 126565), and Thelonectria blattea (CBS 952.68) are also announced here