Hybridization boosters diversification in a Neotropical Bulbophyllum (Orchidaceae) group.

Genetic data shows that cryptic hybrids are more common than previously thought and that hybridization and introgression are widespread processes. Regardless, studies on hybridization are scarce for the highly speciose Bulbophyllum. The genus presents more than 2,200 species and many examples of recent radiations, in which hybridization is expected to be frequent.

Geographic isolation alone does not explain divergence of a group of orchid species across Brazil's campos rupestres sky-islandsIsolamento geográfico por si só não explica a divergência de um grupo de espécies de orquídeas nos campos rupestres do Brasil.

Mountains play a crucial role in the origin and maintenance of Neotropical biodiversity, but there are still unanswered questions about the diversification of the campos rupestres (CR), an herbaceous-shrubby sky-island vegetation in eastern South America. For orchids distributed across this disjunct rock habitat, difficulties with distinguishing morphological taxa add an additional challenge to disentangling the history of divergence. Here, we combined the power of ddRAD genomic data with broad sampling of Bulbophyllum sect.

Plastid phylogenomics of Pleurothallidinae (Orchidaceae): Conservative plastomes, new variable markers, and comparative analyses of plastid, nuclear, and mitochondrial data.

We present the first comparative plastome study of Pleurothallidinae with analyses of structural and molecular characteristics and identification of the ten most-variable regions to be incorporated in future phylogenetic studies. We sequenced complete plastomes of eight species in the subtribe and compared phylogenetic results of these to parallel analyses of their nuclear ribosomal DNA operon (26S, 18S, and 5.8S plus associated spacers) and partial mitochondrial genome sequences (29-38 genes and partial introns).

Asymbiotic germination and morphological studies of seeds of Atlantic Rainforest micro-orchids (Pleurothallidinae).

The morphological and morphometric characters of seeds belonging to 11 species of the subtribe Pleurothallidinae using light and scanning electron microscopy were studied to understand the in vitro germination process. Qualitative data (color, shape, ornamentation) and quantitative ones were also evaluated in seeds and embryos (length, width, volume and air space percentage between the integument and the embryo). The viability of the seeds was evaluated by in vitro germination in woody plant medium (WPM), and by analysis of the developmental stages of protocorms until seedling formation (two to 24 weeks).

Comparative Plastid Genomics of Neotropical (Orchidaceae; Epidendroideae).

Pantropical , with ∼2,200 species, is one of the largest genera in Orchidaceae. Although phylogenetics and taxonomy of the ∼60 American species in the genus are generally well understood, some species complexes need more study to clearly delimit their component species and provide information about their evolutionary history. Previous research has suggested that the plastid genome includes phylogenetic markers capable of providing resolution at low taxonomic levels, and thus it could be an effective tool if these divergent regions can be identified.

Characterization of sequence variability hotspots in Cranichideae plastomes (Orchidaceae, Orchidoideae).

This study reports complete plastome sequences for six species of Neotropical Cranichideae and focuses on identification of the most variable regions (hotspots) in this group of orchids. These structure of these six plastomes is relatively conserved, exhibiting lengths ranging between 142,599 to 154,562 bp with 36.7% GC on average and exhibiting typical quadripartite arrangement (LSC, SSC and two IRs).

Evolution of anatomical characters in Acianthera section Pleurobotryae (Orchidaceae: Pleurothallidinae).

Acianthera section Pleurobotryae is one of ten sections of the genus Acianthera and include four species endemic to the Atlantic Forest. The objective of this study was to describe comparatively the anatomy of vegetative organs and floral micromorphology of all species of Acianthera section Pleurobotryae in order to identify diagnostic characters between them and synapomorphies for the section in relation of other sections of the genus. We analyzed roots, ramicauls, leaves and flowers of 15 species, covering eight of the nine sections of Acianthera, using light microscopy and scanning electron microscopy.

From tree tops to the ground: Reversals to terrestrial habit in Galeandra orchids (Epidendroideae: Catasetinae).

The colonization of the epiphytic niche of Neotropical forest canopies played an important role in orchid's extraordinary diversification, with rare reversions to the terrestrial habit. To understand the evolutionary context of those reversals, we investigated the diversification of Galeandra, a Neotropical orchid genus which includes epiphytic and terrestrial species. We hypothesized that reversion to the terrestrial habit accompanied the expansion of savannas.

ITS and trnH-psbA as Efficient DNA Barcodes to Identify Threatened Commercial Woody Angiosperms from Southern Brazilian Atlantic Rainforests.

The Araucaria Forests in southern Brazil are part of the Atlantic Rainforest, a key hotspot for global biodiversity. This habitat has experienced extensive losses of vegetation cover due to commercial logging and the intense use of wood resources for construction and furniture manufacturing. The absence of precise taxonomic tools for identifying Araucaria Forest tree species motivated us to test the ability of DNA barcoding to distinguish species exploited for wood resources and its suitability for use as an alternative testing technique for the inspection of illegal timber shipments.

Evolution of resupination in Malagasy species of Bulbophyllum (Orchidaceae).

Resupination is the orientation of zygomorphic flowers during development so that the median petal obtains the lowermost position in the mature flower. Despite its evolutionary and ecological significance, resupination has rarely been studied in a phylogenetic context. Ten types of resupination occur among the 210 species of the orchid genus Bulbophyllum on Madagascar.