24 research outputs found

    When hummingbirds are the thieves: visitation effect on the reproduction of Neotropical snowbell Styrax ferrugineus Nees & Mart (Styracaceae) Quando os beija-flores são os ladrões: efeito da visitação na reprodução de uma planta Neotropical Styrax ferrugineus Nees & Mart (Styracaceae)

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    The spectrum of floral visitors associated with a particular plant is frequently larger than predicted by the traditional concept of floral syndromes and the role that unpredicted visitors play in plant reproduction deserves attention. Hummingbirds are frequently recorded visiting flowers with distinct floral syndromes, especially in some hummingbird flower poor ecosystem such as the Cerrado. In this study we investigated the effect of frequent hummingbird visits on the reproduction of melittophilous Styrax ferrugineus. The flowers were visited by many different insect groups and visits by hummingbirds were frequent, especially early in the morning when nectar availability was higher. Nectar parameters varied considerably during the flower life span, and was probably affected by the temperature variation during the day. Hummingbird exclusion experiments showed no effect in the fruit-set of the plant. The inability of hummingbirds to deplete all of the nectar produced in this mass-flowering plant, and the existence of another resource (pollen) for the primary pollinator (large bees), are possible reasons why there was no perceptible hindrance of plant reproduction by the hummingbirds. Although no effect in the fruit-set was observed, the use of non-ornithophilous flowers must be important for hummingbirds, which are specialized nectar consumers.<br>O espectro de visitantes florais associados a uma planta é frequentemente maior que o esperado pelo conceito tradicional de síndromes florais e o papel desses visitantes inesperados tem recebido mais atenção. Os beija-flores freqüentemente visitam flores com síndromes florais distintas, especialmente em alguns ecossistemas pobre em flores ornitófilas como o Cerrado. Investigamos aqui o efeito das visitas de beija-flores na reprodução de Styrax ferrugineus, uma espécie melitófila. As flores foram visitadas por diferentes grupos de insetos e as visitas por beija-flores foram frequentes, especialmente no início das manhãs quando a disponibilidade de néctar foi maior. Os parâmetros de néctar variaram consideravelmente durante a antese, provavelmente afetados pela variação da temperatura durante o dia. Experimentos de exclusão de beija-flores não mostraram efeito sobre a produção de frutos. A incapacidade dos beija-flores em esgotar todo néctar produzido pela planta e a existência de outro recurso floral (pólen) para o polinizador principal (grandes abelhas) são apontadas como razões possíveis para a ausência desse efeito. Embora não tenha sido observado efeito sobre a produção de frutos, o uso de flores não ornitófilas deve ser importante para os beija-flores que são consumidores especializados de néctar

    Nonpreference of whitefly for oviposition in tomato genotypes Não-preferência para oviposição de mosca-branca por genótipos de tomateiro

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    The silverleaf whitefly is one of most important pests of tomato (Lycopersicon spp.). The use of host plant resistance to control this insect is an interesting, potentially useful technique, but in demand of more research. The objectives of this work were to evaluate the oviposition non-preference of Bemisia tabaci (Gennadius, 1889) biotype B for different tomato plant genotypes, evaluating the correlation between oviposition preference and pubescence in the genotypes, and analyzing the abaxial and adaxial surfaces of Lycopersicon pennellii leaflets under the scanning electron microscope. Four wild tomato genotypes, LA 716 (L. pennellii); PI 127826 and PI 127827 (L. hirsutum); PI 134417 (L. hirsutum f. glabratum), and two commercial genotypes, Santa Clara and Bruna VFN hybrid (L. esculentum) were evaluated for number of eggs cm-2 in free and no-choice oviposition tests, using randomized block design and completely randomized design, respectively. The number of trichome was measured in 4 mm² and coefficients of correlation between number of trichomes and number of eggs were calculated. The wild genotypes LA 716 and PI 134417 were less preferred showing oviposition nonpreference resistance type in both tests. The Bruna VFN and Santa Clara were more preferred in free-choice test, while wild genotypes PI 127826 and PI 127827 were more preferred in no-choice test. L. pennellii leaflets presented glandular trichomes type IV in both surfaces. Santa Clara genotype presented higher density of trichomes, and B. tabaci biotype B presented higher preference to oviposition.<br>A mosca-branca Bemisia tabaci (Gennadius, 1889) biótipo B é atualmente uma das principais pragas do tomateiro (Lycopersicon spp.). O uso de plantas resistentes para o controle deste inseto apresenta-se interessante, com grande potencial para Manejo Integrado de Pragas. Este trabalho teve por objetivos verificar a não-preferência para oviposição de B. tabaci biótipo B em genótipos de tomate; avaliar a correlação entre a preferência para oviposição e a pilosidade dos genótipos e analisar a superfície abaxial e adaxial de folíolos de Lycopersicon pennellii em microscópio eletrônico de varredura. Foram utilizados quatro genótipos selvagens, LA 716 (Lycopersicon pennellii); PI 127826 e PI 127827 (L. hirsutum); PI 134417 (L. hirsutum var. glabratum) e dois comerciais, Santa Clara e híbrido Bruna VFN (L. esculentum). Realizaram-se testes com e sem chance de escolha, utilizando para o primeiro o delineamento estatístico em blocos casualizados e para o segundo o delineamento inteiramente casualizado. Em ambos os testes avaliou-se o número de ovos por cm² de folíolo. Para correlacionar a densidade de tricomas com a oviposição nos genótipos, contou-se o número de tricomas em 4 mm². Os genótipos LA 716 e PI 134417 foram os menos preferidos para oviposição nos dois tipos de testes, enquanto os comerciais híbrido Bruna VFN e Santa Clara foram os mais preferidos para oviposição em teste com chance de escolha, e os genótipos selvagens PI 127826 e PI 127827 foram os que apresentaram maior número de ovos cm-2 em teste sem chance de escolha. Os folíolos de L. pennellii apresentaram, nas superfícies abaxial e adaxial, tricomas glandulares do tipo IV. A quantidade de tricomas em 'Santa Clara' propiciou maior oviposição de Bemisia tabaci biótipo B

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

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    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

    Growing knowledge: an overview of Seed Plant diversity in Brazil

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    Growing knowledge: an overview of Seed Plant diversity in Brazil

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    Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora
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