Abundance and Species Richness of Leafhoppers and Planthoppers (Hemiptera: Cicadellidae and Delphacidae) in Brazilian Maize Crops

Fil: De Oliveira, Charles Martins. Embrapa Cerrados. Planaltina. Brasília/DF; BrazilFil: De Oliveira, Elizabeth. Embrapa Milho e Sorgo. Sete Lagoas/MG; BrazilFil: Prazeres De Souza, Isabel Regina. Embrapa Milho e Sorgo. Sete Lagoas/MG; BrazilFil: Alves, Elcio. DuPont do Brazil S.A. DivisÆo Pioneer Sementes. Itumbiara/GO; BrazilFil: Dolezal, William. Pioneer Hi-Bred International. Itumbiara/GO; BrazilFil: Paradell, Susana Liria. División Entomología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Marino de Remes Lenicov, Ana María. División Entomología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Frizzas, Marina Regina. Universidade de Brasília. Departamento de Zoologia. Instituto de Ciências Biológicas. Brasília/DF; Brazi

Chapitre 9. Histoire d’algues

Assemblage typique d'algues dans le Lagon Sud. Canal Woodin, 2015. Au centre Stypopodium lame brune iridescente, mêlée à la délicate dentelle rouge du Kallymenia. © IRD/C. E Payri Les algues, de drôles d’organismes Les algues des récifs coralliens regroupent un ensemble hétérogène d’organismes tous capables de faire la photosynthèse, mais que l’histoire évolutive a fait diverger en plusieurs grandes lignées indépendantes. Bien qu’il n’ait aucune signification taxonomique, le terme « algue » e..

A comprehensive review of the brown macroalgal genus Turbinaria JV Lamouroux (Fucales, Sargassaceae)

WOS:000546220200003International audienceTurbinaria J.V. Lamouroux is a genus of brown algae of the family Sargassaceae (Fucales, Phaeophyceae) found throughout the tropics, subtropics, and occasionally in temperate marine regions. There are currently 22 recognized species, although the taxonomy ofTurbinariais under current refinement with the advancement of genetic analysis techniques for this genus. EcologicallyTurbinariaplays an important role, as its morphology, life history, chemical and mechanical defenses, and rafting dispersal ability have contributed to its increasing distribution across reefs worldwide and to its role in the phase shift from coral to macroalgal reefs worldwide. AlthoughTurbinariais occasionally consumed and used as a fertilizer locally, this genus is not currently highly exploited for industrial use, but research into the potential ofTurbinariaextracts for cosmetic, nutritive, fertilizer, and pharmaceutical industries has yielded some promising results.Turbinaria's alginate, fucoidan, pigment, and unique fatty acid content may prove useful in medical applications due to their antioxidant and anticancer properties

Functional convergence in macroalgal assemblages of isolated coral reefs in the Mozambique Channel

WOS:000457428200004The understanding of macroalgae functions and processes requires a good understanding of the spatial distribution of the functional diversity of macroalgae. In coral reef environments, this information remains fragmentary. Here, based on 314 species sorted according to a set of 10 functional traits, the functional niches of macroalgae at three remote coral reefs of the iles Eparses in the Indian Ocean (Europa, Glorioso, and Juan de Nova) are described. For the comparison of intra- and inter-reef functional structures, we characterized both taxonomic and functional beta diversities, and their turnover and nestedness-resultant components. Within the three reefs, we observed strong taxonomic and functional dissimilarities across sampling sites, mainly determined by turnover. Null models highlighted several processes, which structured macroalgal assemblages across sites: a combined effect of environmental variables (geomorphology and wave exposure), limiting similarity and stochastic effects. At the inter-reef scale, the three reefs only shared a small number of species, but the functional beta diversity between Glorioso and Juan de Nova was weak. This suggested that although assemblages were different, fairly similar environmental conditions may have homogenized macroalgae functions through both ecological and evolutionary scale processes. Our results support the idea that macroalgal assemblages can provide similar functional trait portfolios, despite distinct species composition. We stress the need to focus on macroalgae life-history traits for a better understanding of the processes structuring their communities

Sargassum (Fucales, Phaeophyceae) in Mauritius and Reunion, western Indian Ocean : taxonomic revision and biogeography using hydrodynamic dispersal models

Mauritius and Reunion are part of the Mascarene Islands situated in the southwestern Indian Ocean, c. 800 km east of Madagascar. A total of 44 different Sargassum species and subspecific taxa was listed in the literature for these islands. This was a remarkable number for such isolated and small islands, and was more than have been recorded from Madagascar or other East African countries. The first aim of our study was to revise these species lists using newly collected specimens to provide a reliable and illustrated tool for the identification of the Mauritian and Reunion Sargassum. On the basis of morphological and molecular analyses, a total of six taxa was identified as S. cymosum f. borbonicum, S. obovatum, S. pfeifferae (reinstated), S. polycystum, S. portierianum and S. robillardii (stat. nov.). A seventh taxon, S. scopula, was identified from a herbarium collection but not re-collected. As a result of our taxonomic revision, we concluded that most of the species listed in the literature for both Mauritius and Reunion were misidentifications or synonyms, and we proposed three new taxonomic synonyms. The biogeography of the six Sargassum taxa was further investigated using local and regional hydrodynamic dispersal models. Results underlined the isolated position of the Mascarene Islands with (1) unlikely import of Sargassum in present-day conditions, (2) likely dispersal/exchanges within the archipelago and (3) a two-pronged export of Sargassum to the east coast of Madagascar and the Seychelles with a major stream northwestward and a weaker stream southwestward. These oceanic conditions had probably shaped the Sargassum diversity of the Mascarene Islands and in particular explained the endemicity of S. cymosum f. borbonicum and restricted distribution of S. obovatum, S. pfeifferae, S. robillardii and S. scopula

Comportamiento de diferentes cultivares de trigo a Wheat streak mosaic virus (WSMV) y High Plains virus (HPV) mediante infección artificial con el vector Aceria tosichella Keifer, bajo condiciones de campo

El trigo (Triticum aestivum L.) es el cereal de invierno de mayor importancia económica en la Argentina. Dado que Wheat Streak Mosaic virus (WSMV) y High Plains virus (HPV) constituyen una de las principales limitantes sanitarias del cultivo de trigo, el objetivo del presente trabajo fue evaluar el comportamiento de diferentes cultivares ante ambas enfermedades en infecciones artificiales, bajo condiciones de campo. El inóculo viral mixto WSMV-HPV y el vector A. tosichella se obtuvieron en campo y se multiplicaron en laboratorio. Los eriófidos infectados con ambos virus se utilizaron para realizar las infecciones en campo. Se evaluó la incidencia, el grado de infección y la severidad de síntomas de las infecciones en los diferentes genotipos de trigo. Los cultivares fueron clasificados según la probabilidad de incidencia de cada virus y su interacción, hallándose diferencias significativas sólo en los casos de infecciones con HPV. No se hallaron diferencias significativas en el comportamiento de los cultivares al WSMV. Sólo el 9,2% de los cultivares estudiados presentó infección de ambas virosis. El grado de severidad observado varió entre leve a moderado para las plantas que resultaron infectadas. Los resultados reportados en el presente trabajo constituyen una herramienta potencial para la selección de genotipos con mejor comportamiento en este contexto productivo

Plant-Derived Stilbenoids as DNA-Binding Agents: From Monomers to Dimers

Stilbenoids are natural compounds endowed with several biological activities, including cardioprotection and cancer prevention. Among them, (±)-trans-δ-viniferin, deriving from trans-resveratrol dimerization, was investigated in its ability to target DNA duplex and G-quadruplex structures by exploiting NMR spectroscopy, circular dichroism, fluorescence spectroscopy and molecular docking. (±)-trans-δ-Viniferin proved to bind both the minor and major grooves of duplexes, whereas it bound the 3’- and 5’-ends of a G-quadruplex by stacking on the outer quartets, accompanied by rearrangement of flanking residues. Specifically, (±)-trans-δ-viniferin demonstrated higher affinity for the investigated DNA targets than its monomeric counterpart. Additionally, the methoxylated derivatives of (±)-trans-δ-viniferin and trans-resveratrol, i. e. (±)-pterostilbene-trans-dihydrodimer and trans-pterostilbene, respectively, were evaluated, revealing similar binding modes, affinities and stoichiometries with the DNA targets as their parent analogues. All tested compounds were cytotoxic at μM concentration on several cancer cell lines, showing DNA damaging activity consistent with their ability to tightly interact with duplex and G-quadruplex structures