Gesneriaceae da Serra do Relógio, Descoberto, Minas Gerais State, Brazil / Gesneriaceae da Serra do Relógio, Descoberto, Estado de Minas Gerais, Brasil

The Serra do Relógio is located in the municipality of Descoberto, Zona da Mata in the State of Minas Gerais. There is two important conservation units in this region, Reserva Biológica da Represa do Grama and Reserva Particular do Patrimônio Natural Alto da Boa Vista. Both Conservation Units together cover a total area of ~403 ha of vegetation, mainly semi-deciduous seasonal forest. The Gesneriaceae is represented in the area by eight species, distributed in the genus Besleria (2 spp.), Nematanthus (3 spp.), Paliavana (1 spp.), Sinningia (1 spp.) and Vanhouttea (1spp.). We present descriptions, identification key, comments on taxonomy, distribution and ecology as well as photos of all recorded species.

A Serra do Relógio está localizada no município de Descoberto, Zona da Mata no Estado de Minas Gerais. Há duas importantes Unidades de Conservação, a Reserva Biológica da Represa do Grama (RBRG) e a Reserva Particular do Patrimônio Natural Alto da Boa Vista (RPPNABV). Juntas abrangem uma área total de 402,6 hectares, sendo composta, predominantemente pela Floresta Estacional Semidecidual baixo-montana. Gesneriaceae está representada na área por oito espécies, distribuídas nos gêneros Besleria (2 spp.), Nematanthus (3 spp.), Paliavana (1 spp.), Sinningia (1 spp.) e Vanhouttea (1 spp.). Neste trabalho são apresentadas descrições, chave de identificação, comentários sobre taxonomia, distribuição e ecologia assim como fotos para todas as espécies.

Decoupled evolution of floral traits and climatic preferences in a clade of Neotropical Gesneriaceae.

BACKGROUND: Major factors influencing the phenotypic diversity of a lineage can be recognized by characterizing the extent and mode of trait evolution between related species. Here, we compared the evolutionary dynamics of traits associated with floral morphology and climatic preferences in a clade composed of the genera Codonanthopsis, Codonanthe and Nematanthus (Gesneriaceae). To test the mode and specific components that lead to phenotypic diversity in this group, we performed a Bayesian phylogenetic analysis of combined nuclear and plastid DNA sequences and modeled the evolution of quantitative traits related to flower shape and size and to climatic preferences. We propose an alternative approach to display graphically the complex dynamics of trait evolution along a phylogenetic tree using a wide range of evolutionary scenarios. RESULTS: Our results demonstrated heterogeneous trait evolution. Floral shapes displaced into separate regimes selected by the different pollinator types (hummingbirds versus insects), while floral size underwent a clade-specific evolution. Rates of evolution were higher for the clade that is hummingbird pollinated and experienced flower resupination, compared with species pollinated by bees, suggesting a relevant role of plant-pollinator interactions in lowland rainforest. The evolution of temperature preferences is best explained by a model with distinct selective regimes between the Brazilian Atlantic Forest and the other biomes, whereas differentiation along the precipitation axis was characterized by higher rates, compared with temperature, and no regime or clade-specific patterns. CONCLUSIONS: Our study shows different selective regimes and clade-specific patterns in the evolution of morphological and climatic components during the diversification of Neotropical species. Our new graphical visualization tool allows the representation of trait trajectories under parameter-rich models, thus contributing to a better understanding of complex evolutionary dynamics.

The geographical pattern of speciation and floral diversification in the neotropics: the tribe sinningieae (gesneriaceae) as a case study.

The geographical pattern of speciation and the relationship between floral variation and species ranges were investigated in the tribe Sinningieae (Gesneriaceae), which is found mainly in the Atlantic forests of Brazil. Geographical distribution data recorded on a grid system of 0.5 x 0.5 degree intervals and a near-complete species-level phylogenetic tree of Sinningieae inferred from a simultaneous analysis of seven DNA regions were used to address the role of geographical isolation in speciation. Geographical range overlaps between sister lineages were measured across all nodes in the phylogenetic tree and analyzed in relation to relative ages estimated from branch lengths. Although there are several cases of species sympatry in Sinningieae, patterns of sympatry between sister taxa support the predominance of allopatric speciation. The pattern of sympatry between sister taxa is consistent with range shifts following allopatric speciation, except in one clade, in which the overlapping distribution of recent sister species indicates speciation within a restricted geographical area and involving changes in pollinators and habitats. The relationship between floral divergence and regional sympatry was also examined by analyzing floral contrasts, phenological overlap, and the degree of sympatry between sister clades. Morphological contrast between flowers is not increased in sympatry and phenological divergence is more apparent between allopatric clades than between sympatric clades. Therefore, our results failed to indicate a tendency for sympatric taxa to minimize morphological and phenological overlap (geographic exclusion and/or character displacement hypotheses). Instead, they point toward adaptation in phenology to local conditions and buildup of sympatries at random with respect to flower morphology. Additional studies at a lower geographical scale are needed to identify truely coexisting species and the components of their reproductive isolation.

O primeiro registro de Sinningia gigantifolia Chautems (Gesneriaceae) no estado de São Paulo / Sinningia gigantifolia Chautems (Gesneriaceae) first record in the São Paulo State

Sinningia gigantifolia Chautems é uma espécie rupícola restrita à Serra da Mantiqueira e partes altas da Serra do Mar, que ocorre principalmente em formações florestais. O presente trabalho apresenta o primeiro registro desta espécie para o Estado de São Paulo, na Serra do Baú, em São Bento do Sapucaí. Uma descrição completa da espécie, uma análise da sua distribuição e uma alteração na chave de identificação do gênero Sinningia da Flora Fanerogâmica do Estado de São Paulo são fornecidas.

Sinningia gigantifolia Chautems is a rupicolous species restricted to the Serra da Mantiqueira and higher parts of the Serra do Mar in SE Brazil, ocurring mainly in forest formations. This note presents the first record of this species for São Paulo State, from the Serra do Baú, in São Bento do Sapucaí. A full species description, an analysis of its distribution and a revised key to the genus Sinningia for the Flora Fanerogâmica do Estado de São Paulo are provided.

Systematics and evolution of tribe Sinningieae (Gesneriaceae): evidence from phylogenetic analyses of six plastid DNA regions and nuclear ncpGS.

For nearly all species in the three genera of tribe Sinningieae (Gesneriaceae), Sinningia, Paliavana, and Vanhouttea (mostly in southeastern Brazil) plus 10 outgroups, we have sequenced six non-coding DNA regions (i.e., plastid intergenic spacers trnT-trnL, trnL-trnF, trnS-trnG, atpB-rbcL, and introns in the trnL and rpl16 genes) and four introns in nuclear plastid-expressed glutamine synthetase gene (ncpGS). Separate and combined analyses of these data sets using maximum parsimony supported the monophyly of Sinningieae, but the genera Paliavana and Vanhouttea were found embedded within Sinningia; therefore a new infrageneric classification is here proposed. Mapping of pollination syndromes on the DNA-based trees supported multiple origins of hummingbird and bee syndromes and derivation of moth and bat syndromes from hummingbird flowers. Perennial tubers were derived from perennial stems in non-tuberous plants.

Nectar Sugar Composition in Relation to Pollination Syndromes in Sinningieae (Gesneriaceae).

A putative correlation between nectar sugar composition and pollination syndrome was evaluated in the tribe Sinningieae (Neotropical Gesneriaceae). Sucrose, fructose and glucose were quantified in the nectar of 45 species using high performance anion-exchange chromatography. Representative species of the hummingbird, bee, bat and moth pollination syndromes were sampled in relation to their numeric importance in the tribe. In hummingbird and bee flowers, which represent 95% of the species in Sinningieae, nectar was sucrose-dominant (ratio [sucrose]/[hexose] > 1). Sugar ratios below one were only found in the nectar of three species with moth and bat syndromes. Sugar concentration averaged 23.9 ± 10.6% (wt/total wt) in hummingbird flowers and 28.7 ± 10.6% in bee flowers, whereas diluted nectar (7.1 ± 3.4%) was restricted to bat flowers. Similarities in the nectar of hummingbird and bee flowers contrast with the presence of specific morphological traits associated with these two syndromes, indicating that plant-pollinator relationships rely on flower display rather than on nectar characteristics. By contrast, distinct nectar chemistry is correlated with the bat syndrome in which a particularly low sucrose production is responsible for hexose dominance.