SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Rodrigues,Daniele M.; Turchetto,Caroline; Callegari-Jacques,Sidia M.; Freitas,Loreta B..

ABSTRACT The reproductive system of flowering plants can be highly variable, affecting their biology, gene flow and genetic variability among populations. Petunia secreta is a rare annual endemic species of Pedra do Segredo, located in the municipality of Caçapava do Sul, state of Rio Grande do Sul, Brazil. Although rare, the species possesses a high level of genetic variability. We investigated the reproductive system of P. secreta, including fruit production and seed germinability, in order to determine if its reproductive system can explain its genetic diversity. We sampled five populations and conducted five greenhouse hand-pollination treatments: 1) autonomous apomixis; 2) self-pollination; 3) hand self-pollination; 4) geitonogamy; and 5)...

Ecological drivers of plant genetic diversity at the southern edge of geographical distributions: Forestal vines in a temperate region

Palavras-chave: Endogamy; Pampas; Petunia; Reproductive success; Reproductive system; Seed germinability.

Ano: 2018

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062018000200180

Barros,Michel J.F.; Diniz-Filho,José Alexandre F.; Freitas,Loreta B..

Abstract The Tropical Niche Conservatism hypothesis is one of the most relevant theories to explain why tropical diversity is high, although the mechanisms underlying this hypothesis require further clarification. A possible research avenue to address the underlying mechanisms includes determining population-level processes associated with such a hypothesis, in particular by trying to identify how adaptation may occur in extreme niche conditions at the edges of species ranges. However, the determinants of molecular diversity at the edges of geographical distributions of tropical taxa are still poorly known. Here we assessed which environmental variables determine diversity in nuclear and plastid genetic markers for populations of four Passiflora species in...

Palavras-chave: Distribution edges; Genetic diversity; Passiflora; Niche conservatism; Environmental drivers.

Ano: 2018

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572018000200318

Editorial

Genetic diversity and population structure of naturally rare Calibrachoa species with small distribution in southern Brazil

Freitas,Loreta B..

Tipo: Info:eu-repo/semantics/other

Ano: 2012

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000600001

John,Ana Laura de Wallau; Mäder,Geraldo; Fregonezi,Jeferson N.; Freitas,Loreta B..

Abstract Calibrachoa is a South-American genus comprising 27 species, several considered endemic or rare; few were subjects in genetic studies. We attempted to generate new data about the phylogenetically related and rare species C. eglandulata, C. sendtneriana, C. serrulata, and C. spathulata concerning their genetic diversity and population structure, which, coupled with their known restricted distribution, could help access their conservation status and contribute to the study of the Brazilian biodiversity. We sequenced 88 individuals for plastid intergenic spacers and genotyped 186 individuals for five microsatellite loci. Compared among each other, C. sendtneriana and C. serrulata presented the highest values of genetic diversity [π% (sd) = 0.23...

Genetic diversity in Calibrachoa pygmaea (Solanaceae): A hawkmoth-pollinated nightshade from the Pampas

Palavras-chave: Plastid DNA; Microsatellites; Threatened species; Grasslands; Herbaceous species.

Ano: 2019

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572019000100108

Mäder,Geraldo; Backes,Alice; Reck-Kortmann,Maikel; Freitas,Loreta B..

ABSTRACT Calibrachoa pygmaea is a unique species of Calibrachoa, especially concerning its flower morphology and the environment where it occurs. The species is self-incompatible and is narrowly distributed in wet and flooded fields of the Pampas region. We characterize the genetic diversity of the species based on traditional plastid markers and newly developed nuclear microsatellites to identify drivers that guide its evolution. Our results identified markers that are informative and useful for studying the population structure of C. pygmaea, as well as that of other species of Calibrachoa. Both marker sets were congruent in developing conclusions regarding the evolutionary scenario of C. pygmaea, and revealed that the genetic variability and population...

Molecular evolution and functional divergence of alcohol dehydrogenases in animals, fungi and plants

Palavras-chave: Cross-amplification; Gene flow; Genetic diversity; Plastid haplotypes; Population genetics; SSR markers; Wild petunias.

Ano: 2019

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062019000400664

Thompson,Claudia E.; Freitas,Loreta B.; Salzano,Francisco M..

Abstract Alcohol dehydrogenases belong to the large superfamily of medium-chain dehydrogenases/reductases, which occur throughout the biological world and are involved with many important metabolic routes. We considered the phylogeny of 190 ADH sequences of animals, fungi, and plants. Non-class III Caenorhabditis elegans ADHs were seen closely related to tetrameric fungal ADHs. ADH3 forms a sister group to amphibian, reptilian, avian and mammalian non-class III ADHs. In fishes, two main forms are identified: ADH1 and ADH3, whereas in amphibians there is a new ADH form (ADH8). ADH2 is found in Mammalia and Aves, and they formed a monophyletic group. Additionally, mammalian ADH4 seems to result from an ADH1 duplication, while in Fungi, ADH formed clusters...

Morphological and genetic perspectives of hybridization in two contact zones of closely related species of Petunia (Solanaceae) in southern Brazil

Palavras-chave: Glycolytic proteins; Molecular evolution; Alcohol dehydrogenase; Functional diversification; Positive selection.

Ano: 2018

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572018000200341

Teixeira,Marcelo C.; Turchetto,Caroline; Hartke,Sara; Schnitzler,Carolina K.; Freitas,Loreta B..

ABSTRACT Interspecific hybridization has several consequences for parental species, from blurring species limits to the emergence of new taxa. Petunia axillaris and P. exserta occur in sympatry in southernmost Brazil and naturally hybridize despite their different pollination syndromes and habitat requirements. We employed genetic and morphological analyses to characterize two contact zones between the species with the aim of determining the effect of interspecific hybridization. Microsatellite loci and a morphometric evaluation of the corolla shape were used to classify individuals based on their origin as pure parental or hybrids. Corolla color was used to classify individuals a priori (white, red or intermediate, for P. axillaris, P. exserta or hybrid,...

Patterns of molecular evolution in pathogenesis-related proteins

Palavras-chave: Genetic diversity; Hybridization; Introgression; Morphometric analysis; Petunia.

Ano: 2019

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062019000400734

Scherer,Nicole M.; Thompson,Claudia E.; Freitas,Loreta B.; Bonatto,Sandro L.; Salzano,Francisco M..

The genes encoding 13 classes of pathogenesis-related (PR) proteins were examined for positive selection using maximum-likelihood (ML) models of codon substitution. The study involved 194 sequences from 54 species belonging to 37 genera. Although the sizes of the sequences examined varied from 237 bp for PR12 to 1,110 bp for PR7, most classes (9 out of 13) contained sequences made up of more than 400 nucleotides. Signs of positive selection were obtained for sites in PR proteins 4, 6, 8, 9 and 15 using an ML-based Bayesian method and likelihood ratio tests. These results confirm the importance of positive selection in proteins related to defense mechanisms already observed in a wide array of organisms.

Phylogenetic niche conservatism and plant diversification in South American subtropical grasslands along multiple climatic dimensions

Palavras-chave: Pathogenesis-related proteins; PRs; Molecular variability; Positive selection; Maximum-likelihood methods.

Ano: 2005

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000500001

Barros,Michel J.F.; Silva-Arias,Gustavo A.; Segatto,Ana Lúcia Anversa; Reck-Kortmann,Maikel; Fregonezi,Jeferson N.; Diniz-Filho,José Alexandre F.; Freitas,Loreta B..

Abstract Phylogenetic niche conservatism can be investigated at multiple scales on an explicit geographical context. Haplotype-based comparative analyses of lineages occupying the same region, and thus subjected to similar environmental factors, allow decoupling shared evolutionary and ecological patterns, as well as multiple dimensions of adaptive diversification. Here we aimed to assess the role of environmental drivers on diversification of subtropical grassland, based on haplotypic diversity of two plant genera. We sampled two closely related and co-distributed grassland plant genera, Petunia and Calibrachoa, across their entire distribution area. Eigenvectors extracted from pairwise distances based on chloroplast DNA haplotypes were used to fit...

Phylogeny, biogeography and divergence times in Passiflora (Passifloraceae)

Palavras-chave: Altitude; Climatic changes; Molecular diversification; Phylogenetic niche conservatism.

Ano: 2020

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572020000400602

Muschner,Valéria C.; Zamberlan,Priscilla M.; Bonatto,Sandro L.; Freitas,Loreta B..

As part of a long-term investigation on the evolution of Passiflora L., we investigated the divergence ages of the genus and diversification of its subgenera, relating them with biogeographical and/or historical events, and other characteristics of this taxon. The main aim of the present work was to evaluate the biogeographic distribution of this genus to better understand its evolutionary history. This is the first time that representatives from South American and Old World Passifloraceae genera have been studied as a group comprising a total of 106 widely distributed species, with representative samples of the four suggested subgenera. Seven DNA regions were studied, comprising 7,431 nucleotides from plastidial, mitochondrial and nuclear genomes....

Secondary structure of nrDNA Internal Transcribed Spacers as a useful tool to align highly divergent species in phylogenetic studies

Palavras-chave: Biogeography; Molecular phylogenetics analysis; Passionflowers; Plant evolution; Taxonomic classification.

Ano: 2012

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000600019

Giudicelli,Giovanna C.; Mäder,Geraldo; Silva-Arias,Gustavo A.; Zamberlan,Priscilla M.; Bonatto,Sandro L.; Freitas,Loreta B..

Abstract Recently, it has been suggested that internal transcribed spacer (ITS) sequences are under selective constraints to preserve their secondary structure. Here, we investigate the patterns of the ITS nucleotide and secondary structure conservation across the Passiflora L. genus to evaluate the potential use of secondary structure data as a helpful tool for the alignment in taxonomically complex genera. Considering the frequent use of ITS, this study also presents a perspective on future analyses in other plant groups. The ITS1 and ITS2 sequences presented significant differences for mean values of the lowest energy state (LES) and for number of hairpins in different Passiflora subgenera. Statistical analyses for the subgenera separately support...

Species boundary and extensive hybridization and introgression in Petunia

Palavras-chave: Passiflora; Lowest energy state; Hairpins; ITS1; ITS2.

Ano: 2017

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572017000200191

Turchetto,Caroline; Schnitzler,Carolina K.; Freitas,Loreta B..

ABSTRACT Studying the role of hybridization in the speciation of plants is one of the most thrilling areas of evolutionary biology. Hybridization in natural populations can act in opposition to divergence, contribute to adaptation through introgression or foster the emergence of new lineages via hybrid speciation. Species of the plant genus Petunia grow in open areas in southern South America. Some natural interspecific hybrid events have been described for the genus, such as between the endemic P. exserta and the widespread P. axillaris. Both species occur in sympatry in Serra do Sudeste (Brazil), where they occur in diverse habitats and exhibit floral divergence, which has been related to the attraction of different primary pollinators. The present study...

The use and limits of ITS data in the analysis of intraspecific variation in Passiflora L. (Passifloraceae)

Palavras-chave: Gene exchange; Hybridization; Inbreeding; Introgression; Microsatellite; Petunia; Species limits.

Ano: 2019

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062019000400724

Mäder,Geraldo; Zamberlan,Priscilla M.; Fagundes,Nelson J.R.; Magnus,Tielli; Salzano,Francisco M.; Bonatto,Sandro L.; Freitas,Loreta B..

The discovery and characterization of informative intraspecific genetic markers is fundamental for evolutionary and conservation genetics studies. Here, we used nuclear ribosomal ITS sequences to access intraspecific genetic diversity in 23 species of the genus Passiflora L. Some degree of variation was detected in 21 of these. The Passiflora and Decaloba (DC.) Rchb. subgenera showed significant differences in the sizes of the two ITS regions and in GC content, which can be related to reproductive characteristics of species in these subgenera. Furthermore, clear geographical patterns in the spatial distribution of sequence types were identified in six species. The results indicate that ITS may be a useful tool for the evaluation of intraspecific genetic...