10 research outputs found

    Acacia: the case against moving the type to Australia

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    Recent studies have shown that Acacia is polyphyletic and must be split into five genera. Proposal 1584 would retypify Acacia : the type of the Australian taxon A. penninervis would be conserved over the current lectotype ( A. scorpioides ) of an African taxon. We disagree with the recommendation of the Spermatophyte Committee to endorse this proposal. Contrary to Article 14.12 of the ICBN, no detailed case against conservation was presented in Proposal 1584. We maintain that there are strong arguments against conservation, such as the large number of countries that would be affected, the economic importance of the extra-Australian species, and the economic burden placed on developing countries. Acceptance of this proposal would also violate the guidelines for conservation which clearly state that the principle of priority should prevail when conservation for one part of the world would create disadvantageous change in another part of the world

    Legume phylogeny and classification in the 21st century: Progress, prospects and lessons for other species-rich clades

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    The Leguminosae, the third-largest angiosperm family, has a global distribution and high ecological and economic importance. We examine how the legume systematic research community might join forces to produce a comprehensive phylogenetic estimate for the ca. 751 genera and ca. 19,500 species of legumes and then translate it into a phylogeny-based classification. We review the current state of knowledge of legume phylogeny and highlight where problems lie, for example in taxon sampling and phylogenetic resolution. We review approaches from bioinformatics and next-generation sequencing, which can facilitate the production of better phylogenetic estimates. Finally, we examine how morphology can be incorporated into legume phylogeny to address issues in comparative biology and classification. Our goal is to stimulate the research needed to improve our knowledge of legume phylogeny and evolution; the approaches that we discuss may also be relevant to other species-rich angiosperm clade

    Purificação e caracterização de alfa-galactosidases de sementes de Platymiscium pubescens Micheli Purification and characterization of alpha-galactosidases from Platymiscium pubescens Micheli seeds

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    Este trabalho objetivou foi determinar a composição bioquímica de sementes de espécies florestais e caracterizar a enzima alfa-galactosidase de sementes germinadas de Platymiscium pubescens. Os maiores teores de lipídios foram determinados em sementes de Chorisia speciosa, Caesalpinia peltophoroides, Tabebuia serratifolia e Tabebuia velanedae, enquanto sementes de Enterolobium contortisiliquum, Schizolobium parahyba e Cassia grandis apresentaram os maiores teores protéicos. A alfa-galactosidase catalisa a hidrólise dos oligossacarídeos de rafinose, em sementes de leguminosas, durante a germinação. A maior atividade da alfa-galactosidase foi detectada em sementes de Platymiscium pubescens após 72 h de embebição. Duas formas de alfa-galactosidases, C1 e C2, foram purificadas de sementes germinadas de P. pubescens, usando-se fracionamento com sulfato de amônio e cromatografias de filtração em gel e de afinidade. Essas enzimas apresentaram atividade máxima em pH 5,5 e a 50-55 ºC. Os valores de Km ap das formas C1 e C2, para o substrato ro-nitrofenil-alfa-D-galactopiranosídeo, foram de 0,54 mM e 0,78 mM, e para a rafinose, de 4,64 mM e 5,09 mM, respectivamente. Essas enzimas exibiram estabilidade térmica moderada, mantendo 70% da atividade original após 3 h de incubação a 45 ºC. A atividade enzimática da C1 e C2 foi totalmente perdida na presença de CuSO4 e dodecil sulfato de sódio (SDS). Tais enzimas também hidrolisaram melibiose, rafinose e estaquiose, indicando potencial para aplicações biotecnológicas.<br>The objective of this work was to determine seed biochemical composition of forest species and to characterize alpha-galactosidase enzyme of germinated seeds of Platymiscium pubescens. The highest lipid levels were found in seeds of Chorisia speciosa, Caesalpinia peltophoroides, Tabebuia serratifolia and Tabebuia velanedae, whereas seeds of Enterolobium contortisiliquum, Schizolobium parahyba and Cassia grandis showed the highest protein levels. alpha-galactosidase catalyzes the hydrolyzis of raffinose oligossacarides in legume seeds during germination. The highest activity of alpha-galactosidase was found in seeds of Platymiscium pubescens after 72 h of soaking in the water. Two forms of alpha-galactosidases, C1 and C2, were purified from germinated seeds of P. pubescens, using partition with ammonium sulfate, and gel filtration and affinity chromatographies. These enzymes presented maximum activity at pH 5.5, 50-55ºC. Km ap values in the C1 and C2 forms forrho-nitrophenyl-alpha-D-galactopyranoside substrate were 0.54 mM and 0.78 mM, and 4.64 mM and 5.09 mM for raffinose, respectively. These enzymes showed moderate thermal stability, maintaining 70% of the original activity after 3 h incubation at 45ºC. The C1 and C2 enzymatic activity was totally lost in the presence of CuSO4 and sodium dodecyl sulfate (SDS). These enzymes also hydrolyzed melibiose, raffinose and stachyose, indicating a potential for biotechnological applications

    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
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