Amphicarpy in Trifolium argentinense: morphological characterisation, seed production, reproductive behaviour and life strategy

2013 ◽  
Vol 61 (2) ◽  
pp. 119 ◽  
Author(s):  
Ionara Fatima Conterato ◽  
Maria Teresa Schifino-Wittmann ◽  
Divanilde Guerra ◽  
Miguel Dall'Agnol
Keyword(s):  
Seed Production ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Rio Grande ◽  
Reproductive Behaviour ◽  
Life Strategy ◽  
Rio Grande Do Sul ◽  
Storage Roots ◽  
Mode Of Reproduction ◽  
Native Pastures

Trifolium argentinense Speg. is an amphicarpic species that occurs naturally in native pastures of Rio Grande do Sul, southern Brazil. Amphicarpy is a rare mode of reproduction in which aerial and subterranean seeds are produced by the same individual. In the present paper, we compare morphology, anther number, pollen viability, seed production and mode of reproduction of T. argentinense flowers, and comment on the life strategy of the species. Plants grown from aerial seeds and from the regrowth of storage roots of aerial plants had longer stolons and a larger plant diameter than did those grown from subterranean plants. Plants grown from seeds were also taller than plants grown from storage roots. More resources were allocated to subterranean reproduction in plants of subterranean origin than in those of aerial origin. Aerial flowers produced more seeds, presented more anthers and produced more pollen grains than did the subterranean ones. T. argentinense is a versatile species, self- and cross-pollinated, consistent with the values of high polymorphism information content. T. argentinense adopts the ‘pessimistic strategy’ (early allocation of energy to large subterranean propagules), common in amphicarpic species when growing in disturbed habitats, such as the native pastures of Rio Grande do Sul, where intense grazing and trampling, as well as long seasonal dry spells, may periodically destroy the aerial plants, thus assuring survival by germination of subterranean seeds and regrowth of storage roots.

scholarly journals Characterization and Frequency of Histological Changes in Bovine Livers from Slaughterhouses in Brazil kept on Brachiaria spp.

2017 ◽  
Vol 45 (1) ◽  
pp. 9
Author(s):  
Rebekah Rank Araújo ◽  
Rayane Chitolina Pupin ◽  
Renata Cunha Madureira ◽  
Luiz Gustavo de Morais ◽  
Lucas De Souza Quevedo ◽  
...  
Keyword(s):  
Bile Ducts ◽  
Rio Grande ◽  
Liver Parenchyma ◽  
Rio Grande Do Sul ◽  
Histopathological Changes ◽  
Steroidal Saponins ◽  
Histological Changes ◽  
Mato Grosso ◽  
Native Pastures ◽  
Foamy Macrophages

Background: Brachiaria spp. is the main pasture for ruminant productions in Brazil, but the limiting factor for its use is the toxicity due to the presence of steroidal saponins. Chronic ingestion of Brachiaria spp. by cattle may cause liver changes such as fibrosis, bile duct proliferation and clusters of foamy macrophages in the hepatic parenchyma. The main objective of the present study was to evaluate the most frequent histological changes and their frequencies in livers collected in abattoirs in Brazil from beef cattle raised exclusively on Brachiaria spp. and compare them with those observed in animals kept in Andropogon spp. grass and native pastures in Rio Grande do Sul.Materials, Methods & Results: Liver samples without macroscopic changes were collected in abattoirs from 561 healthy Nelore and Nelore crossbred cattle raised in Brachiaria spp. pastures from Mato Grosso (MT), Mato Grosso do Sul (MS), Minas Gerais (MG) and Pará (PA) States. Liver samples from 84 Angus cattle (Bos taurus) kept on native pastures in Rio Grande do Sul (RS) and from 60 Nelore and Nelore crossbreed cattle raised in Andropogon spp. pastures in Tocantins State (TO) were collected as control. Semi-quantitative analysis of the histopathological changes were proceeded: (-) = no change; (+) = slight or discreet change; (++) = moderate change and (+++) = marked change. The main histopathological changes evaluted in the liver samples were the presence of foamy macrophages and its location, parenchymal fibrosis and its location, proliferation of bile ducts, periportal mononuclear infiltrate, presence of crystals in macrophages and within the bile ducts. Foamy macrophages clusters in the liver parenchyma were the most frequent histological changes exclusively observed in samples of animals kept in Brachiaria spp. and it was more frequent in cattle from MS State (P < 0.0001). The periportal hepatic fibrosis was another relevant finding in cattle kept in Brachiaria spp. and was also more frequent in MS animals (P ≤ 0.0001), and was not present in control groups. Proliferation of the bile ducts rate was similar between animals raised in Brachiaria spp. (P > 0.05), though it was higher in cattle kept on native pasture in RS (P < 0.0001). The mononuclear periportal inflammatory infiltrate was more frequent in MS and MG samples than in MT and PA (P < 0.0002).Discussion: The most significant histopathological changes observed in liver samples of cattle from the states of MT, MS, PA and MG kept in Brachiaria spp. pastures from the birth to slaughter, was the presence of foamy macrophages in quantities and variables distribution showing the strengthen association between clusters of foamy macrophages in the liver parenchyma and grazing on this grass. These macrophages could be found in healthy animals kept in Brachiaria spp. pastures and in intoxicated animals. This change was considered frequent and characteristic in animals kept in pastures containing steroidal lithogenic saponins in its composition, and it was frequently observed in ruminants that growed in Brachiaria spp. pastures. Beef cattle kept in Andropogon spp. grass pastures in the state of Tocantins and native pastures in Rio Grande do Sul did not showed foamy macrophages in liver samples. On the other hand, in susceptible sheep kept in Andropogon spp. grass pastures that  contains low amount of lithogenic steroidal saponins, are insufficient to induce toxicity and morphological changes in the liver, including aggregates of foamy macrophages.

Earthworm diversity in Rio Grande do Sul, Brazil

Zootaxa ◽  
2018 ◽  
Vol 4496 (1) ◽  
pp. 562 ◽  
Author(s):  
GERUSA PAULI KIST STEFFEN ◽  
RICARDO BEMFICA STEFFEN ◽  
MARIE LUISE CAROLINA BARTZ ◽  
SAMUEL WOOSTER JAMES ◽  
RODRIGO JOSEMAR SEMINOTTI JACQUES ◽  
...  
Keyword(s):  
Species Richness ◽  
Native Species ◽  
Rio Grande ◽  
First Record ◽  
Diversity Indices ◽  
Morphological Characters ◽  
Rio Grande Do Sul ◽  
Earthworm Species ◽  
Aporrectodea Trapezoides ◽  
Native Pastures

The knowledge regarding earthworm species richness in subtropical Brazil is limited, particularly in the state of Rio Grande do Sul (RS), where only a few sites have been sampled. In this study we assessed earthworm richness in different ecosystems of RS, prioritizing un-sampled regions. Fifteen ecosystems, including native vegetation and other ecosystems with variable levels of disturbance were sampled in 30 counties in RS, totaling 77 sampling points, mainly in the Pampa biome. Qualitative sampling was performed by handsorting soil monoliths and fixing the earthworms in 4% formalin solution. Species identification was based on morphological characters, and species richness and Shannon (H) and McIntosh (U) diversity indices were calculated for each ecosystem. Twenty-one earthworm species were identified, belonging to seven families: Glossoscolecidae (8), Rhinodrilidae (2), Ocnerodrilidae (4), Megascolecidae (4), Acanthodrilidae (1), Lumbricidae (1) and Criodrilidae (1). From these, ten are new species belonging to the genera: Glossoscolex (6), Fimoscolex (1), Kerriona (1), Eukerria (1), and one aquatic species of the Criodrilidae family, belonging to a new genus. Most of the native species (Urobenus brasiliensis, Fimoscolex n.sp.1 and the Glossoscolex spp.) predominated in ecosystems little altered by human activity, while exotic (Amynthas gracilis, Amynthas rodericensis, Metaphire californica, Aporrectodea trapezoides) and peregrine species (Pontoscolex corethrurus) predominated in areas with more human disturbance. Native ecosystems with lower disturbance, particularly forests and native pastures had higher diversity than disturbed sites. This is the first record of A. rodericencis for Brazil and most sites represent new collection records for the known species in RS.

scholarly journals ESTADO MINERAL DE BOVINOS DE CORTE EM REBANHOS SUPLEMENTADOS NO CENTRO-OESTE DO RIO GRANDE DO SUL

2004 ◽  
Vol 9 (1) ◽  
Author(s):  
D.S. PRESTES ◽  
A.R. FILAPPI ◽  
M. CECIM
Keyword(s):  
Plasma Levels ◽  
Rio Grande ◽  
Inorganic Phosphorus ◽  
Free Access ◽  
Reference Ranges ◽  
Rio Grande Do Sul ◽  
Mineral Supplement ◽  
Mean Values ◽  
Mineral Mixture ◽  
Native Pastures

O presente estudo objetivou analisar os níveis plasmáticos de cálcio (Ca), fósforo inorgânico (Pi), cobre (Cu) e zinco (Zn) em vacas de corte primíparas e multíparas, mantidas em campo nativo e suplementadas com misturas minerais comerciais completas, em rebanhos na região Centro-Oeste do Rio Grande do Sul. Amostras sangüíneas foram colhidas nos períodos de Final de Gestação (FG), Pico da Lactação (PL) e Entoure (E). As médias plasmáticas dos elementos minerais analisados estiveram conforme as referências, com exceção do Pi, nas vacas primíparas, no período de E. Entre períodos, nas vacas primíparas, houve diferença significativa nos níveis de Ca, sendo maiores no PL do que no FG; quanto ao Cu, os níveis foram significativamente maiores no E em relação ao FG; no Zn os níveis foram significativamente menores no PL. Nas multíparas, os níveis de Zn foram significativamente menores no período de PL em relação FG. Entre categorias, os níveis de Ca foram significativamente maiores nas primíparas, no PL; quanto ao Cu, os níveis foram significativamente maiores nas primíparas, no período de PL e E. Nas condições em que o estudo foi conduzido, conclui-se que a suplementação mineral completa provém níveis plasmáticos marginais de cálcio, fósforo inorgânico e cobre em ambas as categorias e em todos os períodos produtivos. Mesmo com suplementação mineral irrestrita, o período produtivo exerce influência sobre os níveis plasmáticos de cálcio, cobre e zinco, nas vacas primíparas. Mineral status of supplemented beef herds in Mid-West Rio Grande do Sul State Abstract The objective of the present study was to analyze plasma levels of calcium (Ca), inorganic phosphorus (Pi), magnesium (Mg), copper (Cu), and zinc (Zn) in heifers and mature cows maintained in native pastures with free access to a complete mineral mixture. Blood samples were collected at the end of gestation (FG), at peak of lactation (PL) and during breeding season (E). The mean values for all minerals were around the lower limit of international reference ranges, with exception of Pi in first calf heifers during breeding. Among periods in heifers, Ca was higher during PL than in FG. Copper levels were higher in E than in FG while zinc values were lowest in PL than in the other two periods. Between categories, Ca levels were higher in PL heifers, and Cu was higher during PL and E than in FG. The present results suggest that supplementation with a complete mineral mix sustained only marginal plasma levels of Ca, Pi, and Cu in both groups in all periods studied. Even with free access to mineral supplement, the period of the productive cycle has an influence on plasma levels of Ca, Cu and Zn in first calf heifers.

scholarly journals Reproductive strategies and dimorphic seeds germination in Trifolium argentinense Speg., an amphicarpic species

2019 ◽  
Vol 25 (3) ◽  
pp. 66-79
Author(s):  
Ionara Fátima Conterato ◽  
Maria Teresa Schifino-Wittmann ◽  
Diego Bitencourt David ◽  
Jorge Dubal Martins
Keyword(s):  
Sexual Reproduction ◽  
Reproductive Strategies ◽  
Vegetative Reproduction ◽  
Rio Grande ◽  
Soil Surface ◽  
Rio Grande Do Sul ◽  
Storage Roots ◽  
Depth Effect ◽  
Seeds Germination ◽  
Better Than

Native from Rio Grande do Sul natural pastures, Trifolium argentinense Speg. has sexual reproduction through aerial and subterranean seeds (amphicarpy) and vegetative reproduction by regrowth from storage roots. In this study the seeds produced at the soil-surface flowers, the depth effect and scarification on the aerial and subterranean seeds germination and the storage roots produced by plants derived from the two types of seeds were evaluated. The aerial (0.10 cm) and soil-surface (0.11 cm) seeds were similar in size, but smaller than the subterranean seeds (0.14 cm), with no significant variation in the production of the three types of seeds. Aerial and subterranean seeds scarified at and sowed 2.5 cm deep germinated better than the scarified and non-scarified seeds sowed on the soil-surface and at 7.0 cm, evincing a depth effect on seed germination. Although amphicarpic, T. argentinense first invests in the production of the storage roots making sure the cloning of specific genotypes and allowing the plants to persist vegetatively year after year without the need for regeneration by seeds in unfavorable environments for sexual reproduction, such as in Rio Grande do Sul natural pastures, where hard grazing and trampling can destroy the aerial part of the plants.  

scholarly journals Significado Peleoecológico de Alguns Palinomorfos Ocorrentes nos Carvões Eopermianos do Rio Grande do Sul, Sul do Brasil

2001 ◽  
Vol 28 (1) ◽  
pp. 81 ◽  
Author(s):  
MIRIAN CAZZULO KLEPZIG
Keyword(s):  
Depositional Environment ◽  
Pollen Grains ◽  
Rio Grande ◽  
Botryococcus Braunii ◽  
Rio Grande Do Sul ◽  
Spores And Pollen ◽  
Incertae Sedis ◽  
Plant Cuticles ◽  
Algal Spores ◽  
South Brazil

Organic-walled palynomorphs of unknown botanical affinity identified in Early Permian coals from Rio Grande do Sul State, South Brazil, together with spores and pollen grains are analysed in this study. Among the identified taxa are: Tetraporina punctate, Tetraporina horologia, Maculatasporites gondwanensis, Brazilea scissa, Quadrisporites horridus, Quadrisporites lobatus, Pilasporites calculus, Portalites gondwanensis. Besides these palynomorphs, some considerations about Botryococcus braunii, a colonial alga occurring in the associations are presented. The morphological similarity between these microfossils and some algal spores spanning in age from Devonian until Recent permit significant comparisons which improve the knowledge on the spectrum of habitats of these palynomorphs. This study corroborates the idea that the peats, originated in lagoons located in coastal plains, were formed by a biomass composed of spores and pollen grains, plant cuticles, wood remains, fungi and algae, in addition to some forms related to Acritarcha or incertae sedis. Minor marine ingressions would be responsible for the occurrence, in the peat-plant association, of elements related to marine microplankton, like acritarchs, thus confirming the inference of a transitional (barrier/lagoon type) depositional environment for the coals as previously suggested by other authors. 

Chromosome numbers, meiotic behavior, and pollen viability of species ofVrieseaandAechmeagenera (Bromeliaceae) native to Rio Grande do Sul, Brazil

2004 ◽  
Vol 91 (6) ◽  
pp. 804-807 ◽  
Author(s):  
Clarisse Palma-Silva ◽  
Daniel G. dos Santos ◽  
Eliane Kaltchuk-Santos ◽  
Maria H. Bodanese-Zanettini
Keyword(s):  
Chromosome Numbers ◽  
Pollen Viability ◽  
Rio Grande ◽  
Meiotic Behavior ◽  
Rio Grande Do Sul

scholarly journals Meiotic behavior of Adesmia DC. (Leguminosae-Faboideae) species native to Rio Grande do Sul, Brazil

1998 ◽  
Vol 21 (3) ◽  
pp. 403-406 ◽  
Author(s):  
Liliana Gressler May Coelho ◽  
Alice Battistin
Keyword(s):  
Seed Production ◽  
Rio Grande ◽  
Pollen Grain ◽  
Meiotic Behavior ◽  
Viable Seed ◽  
Rio Grande Do Sul ◽  
First Time

Meiotic behavior in Adesmia DC. is described for the first time. The study encompassed twelve populations of seven Adesmia DC. species native to Rio Grande do Sul, Brazil. Populations with 2n = 2x = 20 are A. securigerifolia 9615, A. riograndensis 9590 (subnudae), A. latifolia 1568, 1775, 15025, A. bicolor JB-UFSM, A. incana var. incana 9636, 10288, A. punctata var. hilariana 6885, 10812, and A. tristis 10757. A. incana var. incana 9637 is a tetraploid with 2n = 4x = 40. The material was stained with 1% acetic orcein. The meiotic behavior of the populations studied was considered normal. The meiotic index (MI) and the estimates of pollen grain viability were above 95%, except for A. latifolia 1568 (MI = 89%). The present data indicate that these plants are meiotically stable and potentially fertile, apparently with no problems for use in programs of selection, crossing and viable seed production.

scholarly journals Reproductive strategy in the Ranunculus auricomus complex (ranunculaceae)

2014 ◽  
Vol 65 (1-2) ◽  
pp. 167-170 ◽  
Author(s):  
Romana Izmaiłow
Keyword(s):  
Reproductive Strategy ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Morphological Characters ◽  
Mode Of Reproduction ◽  
Individual Level ◽  
Level Number ◽  
Preliminary Study ◽  
The Individual ◽  
Plant Pollen

A preliminary study of reproductive strategy was carried out on plants representing four cytotypes of the <em>Ranunculus auricomus</em> complex. Diploid plants reproduce sexually, triploids, tetraploids and hexaploids have an apomictic mode of reproduction (apospory combined with pseudogamy). Some morphological characters of the plants connected with reproduction were analyzed at various phases and compared in two successive seasons. The following characters were estimated at the individual level: number of ovules and primary pollen grains per plant, pollen viability, pollen-ovule ratio, number of achenes per plant and their germinability, seed-ovule ratio. Most of data characteristic of reproductive strategy were calculated according to the formulae proposed by Urbańska (1989, 1990). Apomictic cytotypes have both a significantly lower pollen viability and seed-ovule ratio (the lowest values in triploids) than sexual diploids.

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