Subfamilies Of Bromeliaceae Research Articles

The seed coat in the evolutionary context of Bromelioideae (Bromeliaceae): morphoanatomical diversity and ontogeny in the core and tankless lineages

Abstract Seed morphology could provide significant characters for understanding the diversification of some clades in Bromeliaceae subfamily Bromelioideae, but little is known about the anatomical diversity and ontogeny of the seed coat in this diverse subfamily. We analysed the morphoanatomy of the seed coat for 48 species from 25 genera of the major lineages of Bromelioideae, from which we selected four species for ontogenetic analysis. Standard techniques for light microscopy were adapted for the anatomical study of seeds. Thirty-three variable characters were described and compared. Flattened or angular usually exappendiculate, tegmic-endotestal seeds, with secondarily thickened endotesta and undulate or costate tegmen, are common characteristics of the tankless lineages. Long oblongoid–obovoid, appendaged or exappendiculate, exclusively tegmic and mucilaginous seeds are common to core Bromelioideae. Anatomical features of the exotegmen and testa and the number of parenchyma layers in the raphe were more variable and especially useful in delimiting genera and some species. The ontogenetic analysis was essential to propose the primary morphological homology hypotheses for the seed coat characters. Seed coat morphoanatomical features offer a promising source of phylogenetically informative characters for integrative and character evolution approaches for Bromelioideae and possibly other subfamilies of Bromeliaceae.

Post-seminal development and cryopreservation of endemic or endangered bromeliads.

Vriesea bahiana, Hohenbergia castellanosii and Encholirium spectabile are endemic Brazilian species that are considered endemic or endangered. Development of strategies to conserve these species is important to prevent irreversible genetic erosion. The objective of this study was to evaluate the post-seminal development and seed cryopreservation of three endemic or in danger of extinction bromeliad species in Brazil, to obtain a protocol that can safeguard the genetic variability of these species. In the seed cryopreservation assay, we evaluated five desiccation periods. The seeds in the cryotubes were taken from the desiccator and immediately plunged into liquid nitrogen. For the analysis of post-seminal development, seeds in different germination stages were collected and evaluated by light and scanning electron microscopy. Vriesea bahiana seeds frozen in liquid nitrogen presented almost 100% germination, indicating dormancy break of this species. Vriesea bahiana can be cryopreserved with 5.9% water content after being dried for 24 hours. Hohenbergia castellanosii and E. spectabile seeds did not need to be desiccated before being cryopreserved. The most relevant morphological traits for differentiation of genera and subfamilies of Bromeliaceae are the shape and type of seed appendages. In this study, all three species presented well-differentiated size and shape of their structures.

Diversity and evolutionary trends of the ovary and ovule in Bromeliaceae

Members of the bromeliads exhibit a great morphological diversity of reproductive organs. In this study, we comparatively analyzed the ovule and ovary anatomy of 23 species, including all Bromeliaceae subfamilies; additionally, the ancestral character optimization for six traits of the ovule was performed. In species with superior ovaries, the carpel displays a homogeneous mesophyll and species with inferior ovaries have a gynoecial hypanthium, which possibly features specific characters such as trichomes in the ovary epidermis, collenchymatous thickening and aerenchyma in the ovary mesophyll. Concerning the ovule, different patterns were recorded for the integument thickness. The inner integument presents little variation in the number of cell layers among the subfamilies, whereas the outer integument shows significant variations in specific taxa. Ancestrally elongated and acuminated, the chalazal appendage displayed distinct morphologies in Catopsis and Puyoideae, while it was reduced in various genera of Bromelioideae. This study demonstrated that many structures in the ovule and ovary of different Bromeliad lineages are more stable than had previously been thought and suggests potentially useful features in the Bromeliaceae taxonomy like collenchymatous thickening and aerenchyma in the gynoecial hypanthium, number of integument cell layers, chalazal appendage type and nucellar epidermal cells. Moreover, unique features observed in ovules of specific lineages are consistent with the form and function of seed and fruit that develop subsequently and play a specific role in diaspore dispersion.

Androecium and gynoecium anatomy of Bromeliaceae species

In this study, we performed a detailed anatomical analysis of the androecium and gynoecium in 16 species belonging to three out of the eight Bromeliaceae subfamilies, with a first-time description of the interlocular zone in anthers, a diagnostic character for Quesnelia and Aechmea species. Other potential taxonomic characters were observed: protuberances formed by growth in the connective region of anthers, which only occurs in species belonging to the Nidularioid complex; and an endothecium-like tissue in the anthers, near to the connective region, characterizing Dyckia species. Besides these characters, the vascularization of filaments and style are discussed from a phylogenetic perspective. In that sense, the vascularization of style is supplied by three vascular bundles that may represent a synapomorphy for Pitcairnoideae and should be further investigated in the family. In addition, the vertical zonality of carpels is described for analyzed inferior and superior ovaries and the position of the nectaries is discussed in this context. Regarding the secretory structures present on the gynoecium we provided novel data for future evolutionary studies on this group. Furthermore, characters presented in this study are discussed from an ecological point of view.

La familia Bromeliaceae en México

Antecedentes: Las Bromeliaceae mexicanas han despertado el interés de los botánicos desde 1789; su estudio sistemático inició a partir de la década de los setenta del siglo pasado, contando actualmente con avances significativos en su conocimiento taxonómico-florístico.Pregunta: ¿Cuántas y cuáles especies de Bromeliaceae se presentan en México? ¿Cómo están distribuidas y cuántas son endémicas?Sitio de estudio: México, 1887-2017.Métodos: Con base en el estudio de las Bromeliaceae de México, incluyendo recolecciones botánicas, revisión de literatura y consulta, cotejo y determinación de ejemplares en 50 herbarios nacionales y extranjeros, se obtuvieron datos sobre riqueza, endemismo y distribución de sus representantes en el país.Resultados: En México están representadas cuatro de las ocho subfamilias de Bromeliaceae, 19 géneros, 422 especies y 8 taxones infraespecíficos. Los géneros más ricos en especies son Tillandsia (230/54.5 %), Hechtia (71/16.8 %) y Pitcairnia (50/11.8 %). Trescientas dieciocho especies, así como los géneros Ursulaea y Viridantha, son endémicos de México; 172 especies son microendémicas. La entidad con más taxones es Oaxaca, seguida por Chiapas, Veracruz y Guerrero y las que cuentan con menor representación son Tlaxcala y Baja California Sur. Baja California, Baja California Sur, Campeche, Ciudad de México, San Luis Potosí, Sonora, Tabasco y Tlaxcala no tienen taxones endémicos estrictos.Conclusión: Aunque el avance del conocimiento de las Bromeliaceae mexicanas ha sido constante, todavía se requiere de trabajo de exploración y recolección en algunas regiones del país, antes de concluir la flora Bromeliológica Mexicana. También es necesario abordar aspectos de conservación y aprovechamiento sustentable.

Chromosome numbers and DNA content in Bromeliaceae: additional data and critical review

For the large Neotropical plant family Bromeliaceae, we provide new data on chromosome numbers, cytological features and genome size estimations, and combine them with data available in the literature. Root-tip chromosome counts for 46 species representing four subfamilies and a literature review of previously published data were carried out. Propidium iodide staining and flow cytometry were used to estimate absolute genome sizes in five subfamilies of Bromeliaceae, sampling 28 species. Most species were diploid with 2n = 50 in Bromelioideae, Puyoideae and Pitcairnioideae, followed by 2n = 48 observed mainly in Tillandsioideae. Individual chromosome sizes varied more than tenfold, with the largest chromosomes observed in Tillandsioideae and the smallest in Bromelioideae. Genome sizes (2C-values) varied from 0.85 to 2.23 pg, with the largest genomes in Tillandsioideae. Genome evolution in Bromeliaceae relies on two main mechanisms: polyploidy and dysploidy. With the exception of Tillandsioideae, polyploidy is positively correlated with genome size. Dysploidy is suggested as the mechanism responsible for the generation of the derived chromosome numbers, such as 2n = 32/34 or 2n = 48. The occurrence of B chromosomes in the dysploid genus Cryptanthus suggests ongoing speciation processes closely associated with chromosome rearrangements. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 176, 349–368.

DNA barcoding Bromeliaceae: achievements and pitfalls.

BackgroundDNA barcoding has been successfully established in animals as a tool for organismal identification and taxonomic clarification. Slower nucleotide substitution rates in plant genomes have made the selection of a DNA barcode for land plants a much more difficult task. The Plant Working Group of the Consortium for the Barcode of Life (CBOL) recommended the two-marker combination rbcL/matK as a pragmatic solution to a complex trade-off between universality, sequence quality, discrimination, and cost.Methodology/Principal FindingsIt is expected that a system based on any one, or a small number of plastid genes will fail within certain taxonomic groups with low amounts of plastid variation, while performing well in others. We tested the effectiveness of the proposed CBOL Plant Working Group barcoding markers for land plants in identifying 46 bromeliad species, a group rich in endemic species from the endangered Brazilian Atlantic Rainforest. Although we obtained high quality sequences with the suggested primers, species discrimination in our data set was only 43.48%. Addition of a third marker, trnH–psbA, did not show significant improvement. This species identification failure in Bromeliaceaecould also be seen in the analysis of the GenBank's matK data set. Bromeliaceae's sequence divergence was almost three times lower than the observed for Asteraceae and Orchidaceae. This low variation rate also resulted in poorly resolved tree topologies. Among the three Bromeliaceae subfamilies sampled, Tillandsioideae was the only one recovered as a monophyletic group with high bootstrap value (98.6%). Species paraphyly was a common feature in our sampling.Conclusions/SignificanceOur results show that although DNA barcoding is an important tool for biodiversity assessment, it tends to fail in taxonomy complicated and recently diverged plant groups, such as Bromeliaceae. Additional research might be needed to develop markers capable to discriminate species in these complex botanical groups.

Geographic distribution of epiphytic bromeliads of the Una region, Northeastern Brazil

Many Brazilian Atlantic Rainforest plant and animal species are geographically restricted to Southern Bahia and Northern Espírito Santo States. We investigated the geographic distribution of epiphytic bromeliads in the lowland forest of the Una region (15° 17' 34' S - 39° 04' 30'' W) in Southern Bahia. Specifically, we addressed the following questions: i) what is the extent of each species distribution?; and ii) are the Bromeliaceae subfamilies distributed differently from one another? Almost half of the 40 species (47.5%) occur exclusively in the Southern Bahia-Northern Espírito Santo region and are herein referred as endemic species. The highest percentage of the 15 species of Tillandsioideae (46.7%) occur throughout the South American Continent and most of the 25 species of Bromelioideae (68.0%) are mainly represented by endemic species. The Una region has almost two times more species than a forested area located 40 km west, suggesting marked increases in diversity in over relatively short distances. The endemism data around Una indicates that species are geographically distributed over an area spanning approximately six to seven degrees in latitude and longitude. This result contrasts with the geographic distribution of Andean epiphytes, mainly represented by Tillandsioideae, that have large geographical distributions. Larger-scale analyses and standardized methods are necessary to verify whether the narrow geographical distribution of most epiphytic bromeliads in the Una region is consistent across different forest types of the Atlantic Rainforest.

Carbohydrate partitioning in the leaves of Bromeliaceae performing C3 photosynthesis or Crassulacean acid metabolism

Carbohydrate accumulation was measured in the leaves of 11 speciesrepresenting the three subfamilies of Bromeliaceae. In the Tillandsioideae the C3 species Vriesea carinata Wawra accumulated starch and sucrose while the Crassulacean acid metabolism (CAM)species Tillandsia tricolor Schlechtendal & Chamissoaccumulated mainly starch. In the Pitcairnioideae the C3species Pitcairnia paniculata Ruiz & Pavon and two CAM species Dyckia sp. andFosterella schidosperma Barker accumulated sucrose butnot starch. Of six CAM species in the Bromelioideae, threeCryptanthus zonatus (Visiani) Beer,Neoregalia spectabilis Moore andPortea petropolitana Wawra accumulated starch but notsoluble sugars while three (Ananus comosus Linnaeus,Orthophytum vagans M.B. Foster andNidularium bilbergioides Schultes filius) accumulatedstarch as well as soluble sugars. Carbohydrate accumulation patterns weresimilar for species within each subfamily in that the Pitcairnioideae speciesdid not accumulate starch but accumulated sucrose while species from theTillandsioideae and Bromelioideae all accumulated starch (some alsoaccumulated soluble sugars). Carbohydrate accumulation patterns were notsimilar for C3 species versus CAM species from thedifferent subfamilies. These data suggest that variations in carbohydratebiochemistry resulting from different evolutionary histories have a greaterinfluence on carbohydrate accumulation patterns in CAM bromeliads than theconstraints of the CAM pathway itself.

Bromeliales, Related Monocots, and Resolution of Relationships among Bromeliaceae Subfamilies

Cladistics, phenetics, and our understanding of chromosomal evolution were applied to questions of the relationships and resemblances among the three subfamilies of the monocot family Bromeliaceae. This large, distinct family (2100 species) is mostly from the new world tropics. Among 10 possibly closely related families to the monotypic order Bromeliales, Velloziaceae of Bromeliflorae appear to be the most likely to share the same common ancestor with Bromeliacae, though other members of Bromeliflorae (and some Zingiberiflorae and Commeliniflorae) are also implicated by the analyses. Nearly all of these sister taxa have the same effect in polarizing mor- phological and anatomical characters. Cladistic analyses placed Bromelioideae and Tillandsioideae as sister taxa and the third subfamily, Pitcairnioideae in close proximity to the family's putative ancestor. A possible explanation of the revealed, multiple lineage relationships and phenetic re- semblances among families is a hybrid, paleopolyploid origin of Bromeliaceae. Chromosome num- bers are in accord with this notion of reticulate evolution having occurred during the origin of the monotypic order, Bromeliales.

Dark CO 2 fixation and the carbon isotope ratio in bromeliaceae

Dark CO 2 fixation and δ 13C values were measured in 27 species of the 3 sub-families of Bromeliaceae. 13 species were in a group with a mean δ 13C value of −12.9±1.2% and with dark CO 2 fixation and 14 species in another group with a mean of −25.3±1.8% 0 . With the exception of Guzmania monostachia, all species showing dark CO 2 fixation, measured colorimetrically or as malate accumulation, had δ 13C values of a C 4 type i.e. showing the least amount of isotope discrimination. These results are consistent with the interpretation that δ 13C values in CAM plants indicate the proportion of the carbon in the plant that entered by either of the two photosynthetic carbon cycles and the degree of ‘openness’ of the ribulose diphosphate (RuDP) carboxylase reaction. The ecological significance of CAM metabolism is indicated by the evidence that species showing net dark CO 2 fixation came from dry epiphytic or terrestrial habitats.