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Santa Fe de la Vera Cruz, Argentina

Bianchi M.B.,Catedra de Botanica | Vesprini J.L.,Catedra de Biologia
Plant Biosystems

The reproductive biology of six native Tillandsia species that co-occurred in woody areas of Santa Fe Province (Argentina) was studied for floral biology, breeding systems and reproductive success. Flower longevity, floral phases, hand self- and cross-pollinations or natural pollinations and fluorescence microscopy observations of post-pollination events were analysed. Also pollen/ovule (P/O) ratio and pre-emergent reproductive success (PERS) were compared between species. In T. aëranthos, T. ixioides and T. meridionalis, self-pollinated flowers mostly failed to form fruits, and fluorescence microscopy studies showed that in selfed pistils pollen tube growth was arrested in the style. It is likely that these species have homomorphic, gametophytic self-incompatibility. In contrast, T. capillaris, T. tricholepis and T. recurvata regularly formed fruits following autonomous self-pollination. Floral traits, the P/O ratios and PERS indices correlate with the breeding systems found in these two groups of species: the three selfing species have inconspicuous closed flowers, and they have low P/O ratios and high PERS values. In contrast, the three self-incompatible (SI) species have conspicuous flowers with relatively high P/O and low PERS values. We described here three new cases of SI in Tillandsia species subgenera Anoplophytum and confirm the autogamous and cleistogamous status in three species of Tillandsia subgenera Diaphoranthema. © 2013, © 2013 Societá Botanica Italiana. Source

Yahara T.,Kyushu University | Javadi F.,Kyushu University | Onoda Y.,Kyoto University | de Queiroz L.P.,State University of Feira de Santana | And 29 more authors.

While many plant species are considered threatened under anthropogenic pressure, it remains uncertain how rapidly we are losing plant species diversity. To fill this gap, we propose a Global Legume Diversity Assessment (GLDA) as the first step of a global plant diversity assessment. Here we describe the concept of GLDA and its feasibility by reviewing relevant approaches and data availability. We conclude that Fabaceae is a good proxy for overall angiosperm diversity in many habitats and that much relevant data for GLDA are available. As indicators of states, we propose comparison of species richness with phylogenetic and functional diversity to obtain an integrated picture of diversity. As indicators of trends, species loss rate and extinction risks should be assessed. Specimen records and plot data provide key resources for assessing legume diversity at a global scale, and distribution modeling based on these records provide key methods for assessing states and trends of legume diversity. GLDA has started in Asia, and we call for a truly global legume diversity assessment by wider geographic collaborations among various scientists. Source

Martinez M.L.,Catedra de Botanica | von Poser G.,Federal University of Rio Grande do Sul | Henriques A.,Federal University of Rio Grande do Sul | Gattuso M.,Catedra de Botanica | Rossini C.,University of the Republic of Uruguay
Industrial Crops and Products

Prospection for new sources of botanical pesticides has shown a revival in the last decades due not only to the fast development of resistance among different pests around the world but also by the need to use less eco-toxic products to control etiological agents of different pest-related problems found in agro-production. In this work, extracts from members of the families Simaroubaceae (Ailanthus altissima, Castela coccinea and Picrasma crenata) and Picramniaceae (Alvaradoa subovata and Picramnia sellowii) were evaluated for their toxicity against the cattle tick and for their antifeedant activity against insects. At the tested doses, none of the extracts exhibited a good toxicity against larvae of the common cattle tick. On the other hand, antifeedant activity was detected in various extracts. Foliage consumption was completely deterred in adults of the specialist Epilachna paenulata in the cases of the C. coccinea leaf and wood extracts and P. crenata wood extract. For larvae of the generalist Spodoptera frugiperda antifeedant effects were also detected, although in a lesser extent. Phytochemical analyses of the extracts showed the presence of alkaloids in P. crenata (including canthin-6-one) and in C. coccinea. Besides, GC/MS analyses of the wood extract from C. coccinea showed the presence of several steroids (ergot 5-en-3-ol-acetate, stigmastan-3,5 diene and stigmasta-3,5dien-7-one). Anthraquinones (emodin and chrysophanol) as well as chlorogenic acid were detected in the cases of A. subovata and P. sellowii extracts. The differences in deterrent activity could not be atributed to differences in the HPLC chemical profiles of the different extracts. © 2012 Elsevier B.V. Source

Mogni V.Y.,Catedra de Botanica | Mogni V.Y.,CONICET | Oakley L.J.,Catedra de Botanica | Prado D.E.,Catedra de Botanica | Prado D.E.,CONICET
Edinburgh Journal of Botany

The Pleistocene Arc Theory (PAT) suggests that present-day disjunct fragments of dry forests in central tropical South America give evidence of a previously more continuous distribution during the Pleistocene that has been disrupted by dry-cold vs. humid-warm climatic cycles. This Arc extends from NE Brazil to NE Argentina and eastern Paraguay, through the Chiquitaniá to NW Argentina and SW Bolivia and into the dry inter-Andean valleys in Peru and Ecuador, with intrusions into the Great Chaco. Seasonally Dry Tropical Forests (SDTFs) are floristically and physiognomically dominated by woody legumes, mostly deciduous in the dry season. In the last two decades field collection and research on legume taxa has greatly increased, with a significant number of taxonomic revisions and molecular phylogenetic studies, together with some paleoclimatic modelling studies. The evidence accumulated in the last 23 years has confirmed the integrity of the Chaco and Caatingas phytogeographical provinces, with an impressive and increasing level of botanical endemism discovered. The PAT pattern has also been supported, specifically through the mapping of five selected woody Leguminosae species (Anadenanthera colubrina, Enterolobium contortisiliquum, Pterogyne nitens, Amburana cearensis and Piptadenia viridiflora). The pre-existing nuclei of South American SDTF (Caatingas, Misiones and Piedmont) are now increased to four with the postulation of the Chiquitaniá Nucleus in south-eastern Bolivia and bordering Paraguay. Some new endemisms are compiled from recent literature and mapped for the Misiones and Chiquitaniá nuclei. The need for more botanical collections and further taxonomic, phylogenetic and demographic studies of South American legumes is emphasised. © 2014 Trustees of the Royal Botanic Garden Edinburgh. Source

Oakley L.J.,Catedra de Botanica | Mogni V.Y.,Catedra de Botanica | Prado D.E.,Catedra de Botanica
Boletin de la Sociedad Argentina de Botanica

Monvillea phatnosperma (Cactaceae), a new record for the Argentinian Flora. The species Monvillea phatnosperma (K. Schum.) Britton & Rose (Cactaceae), is cited and collected for the first time for Argentina, in the province of Formosa. Its distribution is extended within the Great Chaco expanse, since it was only known from Paraguay until now. Some aspects of its morphology, taxonomy and nomenclature are considered. Source

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