As flores possuem uma grande variedade de sistemas sexuais. O mais raro deles é a androdioicia, com poucos casos conhecidos, no qual as espécies apresentam indivíduos ou com flores masculinas ou com flores bissexuais. A maioria das espécies androdioicas evoluiu de ancestrais dioicos, sendo geralmente plantas herbáceas em populações com recorrente extinção local seguida de re-colonização. No entanto, há alguns exemplos de espécies androdioicas e lenhosas cujos ancestrais são hermafroditas. Este é o caso das Annonaceae, uma família pantropical de plantas lenhosas e predominantemente hermafrodita, no qual a androdioicia é frequente. Gêneros androdioicos surgiram várias vezes em diferentes linhagens de Annonaceae, tanto na subfamília Annonoideae, quanto na subfamília Malmeoideae. A maioria dos gêneros androdioicos pertence à subfamília Malmeoideae, um grupo predominantemente asiático. Nas Américas há cinco gêneros androdioicos, todos da tribo Malmeeae, que formam um grupo monofilético, com exceção de Pseudoxandra que, embora membro de Malmeeae, não está incluído no clado dos gêneros androdioicos. Assim, a tribo Malmeeae é um excelente modelo para o estudo da androdioicia em plantas lenhosas neotropicais. Para tanto a reconstrução da filogenia de 33 táxons da tribo Malmeeae foi realizada a partir de sequências de DNA de 66 marcadores moleculares do genoma do cloroplasto, obtidas por sequenciamento de nova geração. Foram realizadas análises de máxima verossimilhança, máxima parcimônia e inferência Bayesiana. A reconstrução dos estados ancestrais de caracteres relacionados ao sistema sexual e morfologia da flor foi realizada numa abordagem Bayesiana. Análises morfo-anatômicas das flores masculinas e bissexuais de Pseudoxandra spiritus-sancti, uma espécie androdioica, foram feitas com microscopia ótica e MEV. Por último, a filogenia morfológica e a revisão taxonômica de Ephedranthus, um gênero androdioico da tribo Malmeeae, são apresentadas / Flowers have a high diversity of sexual systems. The rarest among them is androdioecy, in which species present individuals with male flowers and others with bisexual flowers. The majority of androdioecious species, usually herbaceous plants with recurrent local extinction followed by re-colonization, has evolved from dioecious ancestors. Nevertheless, some woody and androdioecious plants have hermaphrodite ancestors. This is the case of Annonaceae, a pantropical family of woody and hermaphrodite plants, in which androdioecy is frequent. Androdioecious genera have arisen several times in different Annonaceae lineages, both in Annonoideae subfamily and in Malmeoideae subfamily. The majority of androdioecious genera belong to Malmeoideae, a mostly Asian group. In the Americas there are five androdioecious genera, all from tribe Malmeeae, where they compose a monophyletic group, with the exception of Pseudoxandra, which although being a member of Malmeeae, is not included in the androdioecious genera clade. Tribe Malmeeae is, thus, an excellent model to study androdioecy in Neotropical woody plants. The phylogenetic reconstruction of 33 taxa of this group was performed using DNA sequences of 66 molecular markers of the chloroplast genome, sequenced by next generation sequencing. Maximum likelihood, Bayesian inference and maximum parsimony were the methods used for the phylogenetic analyses. The reconstruction of ancestral states were performed to characters related to sexual system and floral morphology using a Bayesian approach. Morphological and anatomical analyses of male and bisexual flowers were done using LM and SEM. A morphological phylogeny and a taxonomic revision of Ephedranthus, an androdioecious genus of tribe Malmeeae, are also presented

As flores possuem uma grande variedade de sistemas sexuais. O mais raro deles é a androdioicia, com poucos casos conhecidos, no qual as espécies apresentam indivíduos ou com flores masculinas ou com flores bissexuais. A maioria das espécies androdioicas evoluiu de ancestrais dioicos, sendo geralmente plantas herbáceas em populações com recorrente extinção local seguida de re-colonização. No entanto, há alguns exemplos de espécies androdioicas e lenhosas cujos ancestrais são hermafroditas. Este é o caso das Annonaceae, uma família pantropical de plantas lenhosas e predominantemente hermafrodita, no qual a androdioicia é frequente. Gêneros androdioicos surgiram várias vezes em diferentes linhagens de Annonaceae, tanto na subfamília Annonoideae, quanto na subfamília Malmeoideae. A maioria dos gêneros androdioicos pertence à subfamília Malmeoideae, um grupo predominantemente asiático. Nas Américas há cinco gêneros androdioicos, todos da tribo Malmeeae, que formam um grupo monofilético, com exceção de Pseudoxandra que, embora membro de Malmeeae, não está incluído no clado dos gêneros androdioicos. Assim, a tribo Malmeeae é um excelente modelo para o estudo da androdioicia em plantas lenhosas neotropicais. Para tanto a reconstrução da filogenia de 33 táxons da tribo Malmeeae foi realizada a partir de sequências de DNA de 66 marcadores moleculares do genoma do cloroplasto, obtidas por sequenciamento de nova geração. Foram realizadas análises de máxima verossimilhança, máxima parcimônia e inferência Bayesiana. A reconstrução dos estados ancestrais de caracteres relacionados ao sistema sexual e morfologia da flor foi realizada numa abordagem Bayesiana. Análises morfo-anatômicas das flores masculinas e bissexuais de Pseudoxandra spiritus-sancti, uma espécie androdioica, foram feitas com microscopia ótica e MEV. Por último, a filogenia morfológica e a revisão taxonômica de Ephedranthus, um gênero androdioico da tribo Malmeeae, são apresentadas / Flowers have a high diversity of sexual systems. The rarest among them is androdioecy, in which species present individuals with male flowers and others with bisexual flowers. The majority of androdioecious species, usually herbaceous plants with recurrent local extinction followed by re-colonization, has evolved from dioecious ancestors. Nevertheless, some woody and androdioecious plants have hermaphrodite ancestors. This is the case of Annonaceae, a pantropical family of woody and hermaphrodite plants, in which androdioecy is frequent. Androdioecious genera have arisen several times in different Annonaceae lineages, both in Annonoideae subfamily and in Malmeoideae subfamily. The majority of androdioecious genera belong to Malmeoideae, a mostly Asian group. In the Americas there are five androdioecious genera, all from tribe Malmeeae, where they compose a monophyletic group, with the exception of Pseudoxandra, which although being a member of Malmeeae, is not included in the androdioecious genera clade. Tribe Malmeeae is, thus, an excellent model to study androdioecy in Neotropical woody plants. The phylogenetic reconstruction of 33 taxa of this group was performed using DNA sequences of 66 molecular markers of the chloroplast genome, sequenced by next generation sequencing. Maximum likelihood, Bayesian inference and maximum parsimony were the methods used for the phylogenetic analyses. The reconstruction of ancestral states were performed to characters related to sexual system and floral morphology using a Bayesian approach. Morphological and anatomical analyses of male and bisexual flowers were done using LM and SEM. A morphological phylogeny and a taxonomic revision of Ephedranthus, an androdioecious genus of tribe Malmeeae, are also presented

No description available.

No description available.

No description available.

Yes / The coexistence of hermaphrodites and female-sterile individuals, or androdioecy, has been documented in only a handful of plants and animals. This study reports its existence in the plant species Cardamine amara (Brassicaceae), in which female-sterile individuals have shorter pistils than seed-producing hermaphrodites. Morphological analysis, in situ manual pollination, microsatellite genotyping and differential gene expression analysis using Arabidopsis microarrays were used to delimit variation between female-sterile individuals and hermaphrodites. Female sterility in C. amara appears to be caused by disrupted ovule development. It was associated with a 2.4- to 2.9-fold increase in clonal propagation. This made the pollen number of female-sterile genets more than double that of hermaphrodite genets, which fulfils a condition of co-existence predicted by simple androdioecy theories. When female-sterile individuals were observed in wild androdioecious populations, their ramet frequencies ranged from 5 to 54 %; however, their genet frequencies ranged from 11 to 29 %, which is consistent with the theoretically predicted upper limit of 50 %. The results suggest that a combination of sexual reproduction and increased asexual proliferation by female-sterile individuals probably explains the invasion and maintenance of female sterility in otherwise hermaphroditic populations. To our knowledge, this is the first report of the coexistence of female sterility and hermaphrodites in the Brassicaceae.

No description available.

The Mercurialis annua L. (Euphorbiaceae) species complex comprises a group of closely related lineages that present a wide range of sexual-systems, making it a valuable model for the study of plant sexual-system evolution. Within this polyploid complex, diploid populations are dioecious, and polyploid populations either monoecious or androdioecious (males coexist with functional hermaphrodites). The primary aim of this thesis was to use patterns of genetic diversity to elucidate the evolutionary origin and maintenance of the sexual-system diversity in M. annua. The phylogeny of the M. annua complex was reconstructed using chloroplast and ITS DNA sequence. This, in conjunction with morphometric analysis, showed that both hexaploid M. annua, and a novel species from the Canary Islands (newly described here as Mercurialis canariensis), were allopolyploid in origin. Such an origin for hexaploid M. annua suggests that androdioecy may have been able to arise in this group as a consequence of hybridisation between a monoecious lineage, tetraploid M. annua, and a dioecious lineage, M. huetii. Artificial crosses were used to show that hexaploid M. annua has disomic marker inheritance, and a statistical approach was developed to quantify genetic diversity and differentiation in polyploids with disomic inheritance. Strong gradients in genetic (allozyme) diversity at a pan-European scale were used to infer the existence of separate glacial refugia for dioecious and monoecious races of M. annua, at the eastern and western ends of the Mediterranean basin, respectively. A metapopulation model had previously been proposed to explain the ecological maintenance of androdioecy in M. annua. Here, population-level patterns of genetic diversity were used as an indirect test of this model. The discovery of lower within-population diversity, and of greater genetic differentiation between populations, for monoecious populations than for androdioecious populations was consistent with the metapopulation model, and suggests that androdioecy is maintained by the occurrence of regular local extinction.

No description available.

No description available.