Distribuição atual das populações de Arachis villosa Benth. (Fabaceae) no Uruguai

Resumen enviado al VII CBRG, Congresso Brasileiro de Recursos Genéticos, del 8 al 11 de Noviembre de 2022. El Congreso fue realizado por la EMBRAPA Clima Temperado en la modalidad virtual. Link a la página del congreso.Agencia Nacional de Investigación e Innovació

Comparative repeatome analysis reveals new evidence on genome evolution in wild diploid Arachis (Fabaceae) species

The South American genus Arachis (Fabaceae) comprises 83 species organized in nine taxonomic sections. Among them,section Arachis is characterized by species with a wide genome and karyotype diversity. Such diversity is determined mainlyby the amount and composition of repetitive DNA. Here we performed computational analysis on low coverage genomesequencing to infer the dynamics of changes in major repeat families that led to the differentiation of genomes in diploidspecies (x = 10) of genus Arachis, focusing on section Arachis. Estimated repeat content ranged from 62.50 to 71.68% ofthe genomes. Species with different genome composition tended to have different landscapes of repeated sequences. Athilafamily retrotransposons were the most abundant and variable lineage among Arachis repeatomes, with peaks of transpositionalactivity inferred at different times in the evolution of the species. Satellite DNAs (satDNAs) were less abundant, butdifferentially represented among species. High rates of evolution of an AT-rich superfamily of satDNAs led to the differentialaccumulation of heterochromatin in Arachis genomes. The relationship between genome size variation and the repetitivecontent is complex. However, largest genomes presented a higher accumulation of LTR elements and lower contents ofsatDNAs. In contrast, species with lowest genome sizes tended to accumulate satDNAs in detriment of LTR elements. Phylogeneticanalysis based on repetitive DNA supported the genome arrangement of section Arachis. Altogether, our resultsprovide the most comprehensive picture on the repeatome dynamics that led to the genome differentiation of Arachis species.Fil: Samoluk, Sergio Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Vaio, Magdalena. Universidad de la Republica; UruguayFil: Ortiz, Alejandra Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Chalup, Laura María Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Robledo Dobladez, Germán Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Bertioli, David J.. University of Georgia; Estados UnidosFil: Seijo, José Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin

Guardianes y guardianas de semilla de maní en Uruguay

Trabajo presentado en el II congreso Argentino de Agroecología, realizado entre el 13 al 15 de octubre de 2021. Evento Organizado por la Sociedad Argentina de Agroecología, Chaco, Argentina. Evento Virtual.Agencia Nacional de Investigación e Innovació

Análises citogenéticas em Paspalum L. revelam novas espécies e acessos diplóides

Se contaron los números de cromosomas en 126 nuevas accesiones de 50 especies de Paspalum de Brasil, Argentina, Paraguay y Bolivia. Se confirmaron los números de cromosomas 2n = 12, 20, 24, 30, 40, 50, 60, 80. Números de cromosomas para P. arenarium (2n = 20), P. barretoi (2n = 20), P. aff. ceresia (2n = 40), P. corcovadense (2n = 20), P. crispulum (2n = 20), P. flaccidum (2n = 40), P. nummularium (2n = 20), P. scalare (2n = 20) ), P. vescum (2n = 20) y P. rectum (2n = 20) y un citotipo diploide de P. malacophyllumse informan por primera vez. Se confirmó el predominio de accesiones tetraploides (43,6%), pero se encontró un número inusualmente alto de especies diploides (44%) y accesiones (35,7%). Estos resultados abren nuevas perspectivas para programas de mejoramiento, estudios filogenéticos y para la investigación sobre el control de la apomixis, ya que los diploides de Paspalum son típicamente sexuales.O número cromossômico foi determinado para 126 novos acessos de 50 espécies de Paspalum do Brasil, Argentina, Paraguai e Bolívia. Foram verificados os números somáticos 2n = 12, 20, 24, 30, 40, 50, 60 e 80. Estas são as primeiras contagens para P. arenarium (2n = 20), P. barretoi (2n = 20), P. aff . ceresia (2n = 40), P. corcovadense (2n = 20), P. crispulum (2n = 20), P. flaccidum (2n = 40), P. nummularium (2n = 20), P. scalare (2n = 20) ), P. vescum (2n = 20) y P. recto (2n = 20). O nível diplóide (2n = 20) é reportado pela primeira vez para P. malacophyllum. Os dados confirmam a predominância de acessos tetraplóides (43,6%) no gênero e mostram um número incomumente elevado de espécies (44%) e acessos diplóides (35,7%). Estes resultados trazem novas perspectivas para programas de melhoramento, para estudos filogenéticos e para pesquisa orientada ao controle da apomixia, já que em Paspalum as plantas diplóides são tipicamente sexuais.Fil: Pozzobon, Marisa Toniolo. Parque Estação Biológica; BrasilFil: Carvalho, Ana Caroline Machado De. Universidade do Brasília; BrasilFil: Vaio, Magdalena. Universidad de la República; UruguayFil: Valls, José Francisco M.. Parque Estação Biológica; BrasilFil: Peñaloza, Andréa Del Pilar De Souza. Parque Estação Biológica; BrasilFil: Santos, Sileuza Dos. Parque Estação Biológica; BrasilFil: Côrtes, Ana Luiza. Centro Universitário de Brasília; BrasilFil: Rua, Gabriel Hugo. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Botánica Agrícola; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Buscando el maní perdido: estudio de la diversidad genética y estado de conservación de Arachis hypogaea en Uruguay

Trabajo presentado en el Congreso Nacional de Biociencias, 19-21 de Octubre 2022, Uruguay.Agencia Nacional de Investigación e Innovació

A phylogenetic analysis of the genus Paspalum (Poaceae) based on cpDNA and morphology

With about 350 species, Paspalum is one of the richest genera within the Poaceae. Its species inhabit ecologically diverse areas along the Americas and they are largely responsible for the biodiversity of grassland ecosystems in South America. Despite its size and relevance, no phylogeny of the genus as a whole is currently available and infrageneric relationships remain uncertain. Many Paspalum species consist of sexual-diploid and apomictic-polyploid cytotypes, and several have arisen through hybridization. In this paper we explore the phylogenetic structure of Paspalum using sequence data of four non-coding cpDNA fragments from a wide array of species which were combined with morphological data for a subset of diploid taxa. Our results confirmed the general monophyly of Paspalum if P. inaequivalve is excluded and the small genus Thrasyopsis is included. Only one of the four currently recognized subgenera was monophyletic but nested within the remainder of the genus. Some informal morphological groups were found to be polyphyletic. The placement of known allopolyploid groups is generally congruent with previously stated hypotheses although some species with shared genomic formulae formed paraphyletic arrangements. Other species formed a basal grade including mostly umbrophilous or hygrophilous species. It is hypothesized that the genus may have diversified as a consequence of the expansion of C4 grass-dominated grasslands in South America. © 2010 Springer-Verlag.Fil: Rua, Gabriel Hugo. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Botánica Agrícola; ArgentinaFil: Speranza, Pablo. Universidad de la República; UruguayFil: Vaio, Magdalena. Universidad de la República; UruguayFil: Arakaki, Mónica. University Brown; Estados Unido

Origins of polyploidy in Paspalum stellatum and related species (Poaceae, Panicoideae, Paspaleae) inferred from phylogenetic and cytogenetic analyses

Paspalum stellatum is widely distributed in the American continent and it is known to include diploid cytotypes (2n = 2x = 20) and polyploid cytotypes (2n = 32 and 52). It is closely related to P. eucomum, P. malmeanum and P. schesslii. After chromosome counting and geographical mapping of the different cytotypes, phylogenetic relationships between them were explored in order to infer the origin and evolution of the polyploid complex P. stellatum and related species. Additionally, several unusual chromosome numbers are here reported for P. stellatum (2n = 30, 46, 48, 56 and 60) from the Brazilian cerrado. Phylogenetic analysis using plastid DNA showed that the cytotypes of P. stellatum split into two clades, one of which included all accessions with 2n = 32 and P. schesslii. Using ITS for phylogenetic analysis showed that P. schesslii, P. malmeanum and P. eucomum were grouped together as expected. The origin of the cytotype 2n = 32 of P. stellatum may have involved P. schesslii as one of the putative progenitors with a diploid cytotype of P. stellatum as the other.Fil: Bonasora, Marisa Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: López, Alicia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vaio, Magdalena. Universidad de la República; UruguayFil: Speranza, Pablo R.. Universidad de la República; UruguayFil: Honfi, Ana Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; ArgentinaFil: Rua, Gabriel Hugo. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Comparative analysis of repetitive sequences among species from the potato and the tomato clades

Background and AimsThe genus Solanum includes important vegetable crops and their wild relatives. Introgression of their useful traits into elite cultivars requires effective recombination between hom(e)ologues, which is partially determined by genome sequence differentiation. In this study we compared the repetitive genome fractions of wild and cultivated species of the potato and tomato clades in a phylogenetic context.MethodsGenome skimming followed by a clustering approach was used as implemented in the RepeatExplorer pipeline. Repeat classes were annotated and the sequences of their main domains were compared.Key ResultsRepeat abundance and genome size were correlated and the larger genomes of species in the tomato clade were found to contain a higher proportion of unclassified elements. Families and lineages of repetitive elements were largely conserved between the clades, but their relative proportions differed. The most abundant repeats were Ty3/Gypsy elements. Striking differences in abundance were found in the highly dynamic Ty3/Gypsy Chromoviruses and Ty1/Copia Tork elements. Within the potato clade, early branching Solanum cardiophyllum showed a divergent repeat profile. There were also contrasts between cultivated and wild potatoes, mostly due to satellite amplification in the cultivated species. Interspersed repeat profiles were very similar among potatoes. The repeat profile of Solanum etuberosum was more similar to that of the potato clade.ConclusionsThe repeat profiles in Solanum seem to be very similar despite genome differentiation at the level of collinearity. Removal of transposable elements by unequal recombination may have been responsible for structural rearrangements across the tomato clade. Sequence variability in the tomato clade is congruent with clade-specific amplification of repeats after its divergence from S. etuberosum and potatoes. The low differentiation among potato and its wild relatives at the level of interspersed repeats may explain the difficulty in discriminating their genomes by genomic in situ hybridization techniques