Network analyses show horizontal and vertical distribution of vascular epiphytes on their hosts in a fragment of cloud forest in Central Mexico.

Cloud forests figure as one of the most diverse ecosystems, accounting not only for a high number of plant species but also with a great variety of interactions among them. A common interaction in these forests is the one between vascular epiphytes and their hosts. However, few studies have used the network approach to analyze them. Here, we analyze the horizontal and vertical structure of the vascular epiphyte - host network in a cloud forest in central Mexico. We quantified the number of epiphyte stands on each host both total and per-stratum. Complete network, group, and species metrics were estimated at both levels of analysis. The host - epiphyte networks had relatively low network size but were highly connected; moderately nested, with low specialization, and modularity; but higher vulnerability than generality, and high niche overlap. The community was composed by a high number of generalist species. To our knowledge this is the first study in which network analyses are conducted with standardized data and including all host and epiphyte species in the community. The analyses suggest that the networks are robust, and that functional redundancy might be probable, two advantageous characteristics in a very fragmented and threatened cloud forest.

New insights into the role of the root system of epiphytic bromeliads: comparison of root and leaf trichome functions in acquisition of water and nutrients.

BACKGROUND: In epiphytic bromeliads, the roots used to be considered poorly functional organs in the processes of absorption and metabolization of water and nutrients, while the leaves always acted as protagonists in both functions. More recent discoveries have been changing this old view of the root system. SCOPE: In this review, we will address the old thoughts of the scientific community regarding the function performed by the roots of epiphytic bromeliads (mere holdfast structures with low physiological activity) and the importance of a reduced or lack of root system for the emergence of epiphytism. We will present indirect and direct evidence that contradicts this older hypothesis. Furthermore, the importance of the root absorptive function mainly for juvenile tankless epiphytic bromeliads and the characteristics of the root absorption process of adult epiphytic tank bromeliads will be thoroughly discussed in physiological aspects. Finally, some factors (species, substrate, environmental conditions) that influence the absorptive capability of the roots of epiphytic tank bromeliads will also be considered in this review, highlighting the importance that the absorptive role of the roots have for the plasticity of bromeliads that live on trees, which is an environment characterized by the intermittent availability of water and nutrients. CONCLUSIONS: The roots of tank-forming epiphytic bromeliads play important roles in the absorption and metabolization of nutrients and water. The importance of roots stands out mainly for juvenile tankless bromeliads since the root is the main absorptive organ. In larger plants with tank, although the leaves become the protagonists in the resource acquisition process, the roots complement the absorptive function of the leaf trichomes, resulting in a better growth of the bromeliad. The physiological and biochemical properties of the processes of absorption and distribution of resources in the tissues seem to differ between absorption by trichomes and roots.

Floral pigments and their perception by avian pollinators in three Chilean Puya species.

The Chilean Puya species, Puya coerulea var. violacea and P. chilensis bear blue and pale-yellow flowers, respectively, while P. alpestris considered to be their hybrid-derived species has unique turquoise flowers. In this study, the chemical basis underlying the different coloration of the three Puya species was explored. We first isolated and identified three anthocyanins: delphinidin 3,3',5'-tri-O-glucoside, delphinidin 3,3'-di-O-glucoside and delphinidin 3-O-glucoside; seven flavonols: quercetin 3-O-rutinoside-3'-O-glucoside, quercetin 3,3'-di-O-glucoside, quercetin 3-O-rutinoside, isorhamnetin 3-O-rutinoside, myricetin 3,3',5'-tri-O-glucoside, myricetin 3,3'-di-O-glucoside and laricitrin 3,5'-di-O-glucoside; and six flavones: luteolin 4'-O-glucoside, apigenin 4'-O-glucoside, tricetin 4'-O-glucoside, tricetin 3',5'-di-O-glucoside, tricetin 3'-O-glucoside and selagin 5'-O-glucoside, which is a previously undescribed flavone, from their petals. We also compared compositions of floral flavonoid and their aglycone among these species, which suggested that the turquoise species P. alpestris has an essentially intermediate composition between the blue and pale-yellow species. The vacuolar pH was relatively higher in the turquoise (pH 6.2) and pale-yellow (pH 6.2) flower species, while that of blue flower species was usual (pH 5.2). The flower color was reconstructed in vitro using isolated anthocyanin, flavonol and flavone at neutral and acidic pH, and its color was analyzed by reflectance spectra and the visual modeling of their avian pollinators. The modeling demonstrated that the higher pH of the turquoise and pale-yellow species enhances the chromatic contrast and spectral purity. The precise regulation of flower color by flavonoid composition and vacuolar pH may be adapted to the visual perception of their avian pollinator vision.

Selfing in epiphytic bromeliads compensates for the limited pollination services provided by nectarivorous bats in a neotropical montane forest.

Abstract. Plants with specialized pollination systems frequently exhibit adaptations for self-pollination, and this contradictory situation has been explained in terms of the reproductive assurance function of selfing. In the neotropics, several plant lineages rely on specialized vertebrate pollinators for sexual reproduction, including the highly diverse Bromeliaceae family, which also displays a propensity for selfing. Thus far, the scarce evidence on the role of selfing in bromeliads and in other neotropical plant groups is inconclusive. To provide insights into the evolution and persistence of self-fertilization in the breeding systems of Bromeliaceae, we studied four sympatric epiphytic species from the genus Werauhia (Tillandsioideae) in Costa Rica. We documented their floral biology, pollination ecology and breeding systems. We estimated the contribution of selfing by comparing the reproductive success between emasculated flowers requiring pollinator visits and un-manipulated flowers capable of selfing and exposed to open pollination across two flowering seasons. The studied species displayed specialized pollination by nectar-feeding bats as well as a high selfing ability (auto-fertility index values > 0.53), which was attained by a delayed selfing mechanism. Fruit set from natural cross-pollination was low (<26% in both years) and suggested limited pollinator visitation. In line with this, we found a very low bat visitation to flowers using video-camera recording, from 0 to 0.24 visits per plant per night. On the contrary, the contribution of selfing was comparatively significant since 54-80% of the fruit set from un-manipulated flowers can be attributed to autonomous self-pollination. We concluded that inadequate cross-pollination services diminished the reproductive success of the studied Werauhia, which was compensated for by a delayed selfing mechanism. The low negative effects of inbreeding on seed set and germination likely reinforce the persistence of selfing in this bromeliad group. These results suggest that selfing in bat-pollinated bromeliads may have evolved as a response to pollinator limitation.

Transcriptome data from silica-preserved leaf tissue reveal gene flow patterns in a Caribbean bromeliad.

BACKGROUND AND AIMS: Transcriptome sequencing is a cost-effective approach that allows researchers to study a broad range of questions. However, to preserve RNA for transcriptome sequencing, tissue is often kept in special conditions, such as immediate ultracold freezing. Here, we demonstrate that RNA can be obtained from 6-month-old, field-collected samples stored in silica gel at room temperature. Using these transcriptomes, we explore the evolutionary relationships of the genus Pitcairnia (Bromeliaceae) in the Dominican Republic and infer barriers to gene flow. METHODS: We extracted RNA from silica-dried leaf tissue from 19 Pitcairnia individuals collected across the Dominican Republic. We used a series of macro- and micro-evolutionary approaches to examine the relationships and patterns of gene flow among individuals. KEY RESULTS: We produced high-quality transcriptomes from silica-dried material and demonstrated that evolutionary relationships on the island match geography more closely than species delimitation methods. A population genetic examination indicates that a combination of ecological and geographical features presents barriers to gene flow in Pitcairnia. CONCLUSIONS: Transcriptomes can be obtained from silica-preserved tissue. The genetic diversity among Pitcairnia populations does not warrant classification as separate species, but the Dominican Republic contains several barriers to gene flow, notably the Cordillera Central mountain range.

Actualización de la flora epífita del Perú / Update of the epiphytic flora of Peru

Resumen A pesar de la alta diversidad de epífitas vasculares (EV) reportadas en Perú, no existe un listado actualizado que esté acorde con las nuevas delimitaciones taxonómicas y los nuevos conceptos de epífitas. En este trabajo actualizamos el listado de EV de Perú, a partir de una búsqueda bibliográfica y visitas a herbarios locales. Se actualizaron los nombres de las especies según World Flora Online, se confirmó su presencia en la EpiList, su distribución altitudinal y por departamento, su categoría de riesgo y endemismo; y finalmente, se estimó el coeficiente epífito. Encontramos 2462 especies, pertenecientes a 18 órdenes, 25 familias y 249 géneros. Las familias con mayor riqueza fueron Orchidaceae (1606), Bromeliaceae (201) y Piperaceae (139 spp.); el 85 % de las especies estaban en la EpiList (2088 spp.). El departamento con mayor riqueza fue Amazonas (709) y los de menor fueron Ica y Tacna (2 spp.). El rango altitudinal con mayor riqueza se ubica entre los 1501 - 2000 m (649); 689 especies son endémicas y 220 se encuentran en alguna categoría de riesgo; el cociente epífito es de 13.12. Esta actualización representa un incremento aproximado del 40%, lo que posiciona a Perú como el tercer país con mayor diversidad de EV. Se obtuvo un listado más completo y acorde con el concepto de epifitismo; con lo que se hace evidente la necesidad de incluir 384 especies a la EpiList, lo que ayudaría a complementar el listado global de EV en el mundo.

Abstract Despite the high diversity of vascular epiphytes (VE) reported in Peru, there is no updated checklist that is in line with the new taxonomic delimitations and the new concepts of epiphytes. In this study, we update the list of VE in Peru, based on a bibliographic search and visits to local herbaria. Species names were updated according to the World Flora Online, their presence in the EpiList was confirmed, as well as their altitudinal distribution and distribution by department, risk category, and endemism. Finally, the epiphyte coefficient was estimated. We found 2462 species, belonging to 18 orders, 25 families, and 249 genera. The families with the highest richness were Orchidaceae (1606), Bromeliaceae (201), and Piperaceae (139 spp.); 85% of the species were in the EpiList (2088 spp.). The department with the highest richness was Amazonas (709) and the lowest were Ica and Tacna (2 spp.). The altitudinal range with the highest richness is between 1501 - 2000 m (649); 689 species are endemic and 220 are in some risk category; the epiphyte quotient is 13.12. This update represents an approximate 40% increase, positioning Peru as the third country with the highest VE diversity. A more comprehensive list was obtained, in line with the concept of epiphytism, highlighting the need to include 384 species in the EpiList, which would help complement the global list of VE worldwide.

Drought memory in Acanthostachys strobilacea, a CAM epiphytic bromeliad.

Stress memory is the development of altered responses to stress due to previous exposure, which might result in increased tolerance. Biochemical and physiological parameters shown to be positively affected by stress memory include those of the antioxidant and nitrosative metabolism, photosynthetic pigments and osmolyte content. Epiphytic bromeliads likely present stress memory since they experience frequent droughts in the canopies. Thus, we aimed to evaluate if the epiphytic bromeliad Acanthostachys strobilacea (Schult. & Schult.f.) Klotzsch shows improved metabolic stress defence responses to a second drought and rewatering cycle compared to a single exposure. In a controlled environment chamber, 90-day-old plants were exposed to one or two drought-rewatering cycles of 14 days without irrigation and 5 days of rewatering each. Sampling occurred after the final drought and rewatering periods for one or two cycles treatments. The free amino acid, chlorophyll, and carotenoid levels and S-nitrosoglutathione reductase (GSNOR) activity were higher at the second drought than at the first exposure. The rise in nocturnal acidification (indicative of increased CAM activity) caused by the initial drought persisted through the second drought-rewatering cycle, implying a lasting memory effect on CAM activity. Furthermore, the second recovery did not induce glutathione accumulation, as in the first rewatering event, suggesting the pre-exposure to drought reduced this thiol's demand during a later recovery. Our results evidence metabolic changes related to drought stress memory in A. strobilacea, supporting this mechanism might be involved in the tolerance of epiphytic bromeliads to intermittent droughts.

Tillandsia landbeckii phyllosphere and laimosphere as refugia for bacterial life in a hyperarid desert environment.

BACKGROUND: The lack of water is a major constraint for microbial life in hyperarid deserts. Consequently, the abundance and diversity of microorganisms in common habitats such as soil are strongly reduced, and colonization occurs primarily by specifically adapted microorganisms that thrive in particular refugia to escape the harsh conditions that prevail in these deserts. We suggest that plants provide another refugium for microbial life in hyperarid deserts. We studied the bacterial colonization of Tillandsia landbeckii (Bromeliaceae) plants, which occur in the hyperarid regions of the Atacama Desert in Chile, one of the driest and oldest deserts on Earth. RESULTS: We detected clear differences between the bacterial communities being plant associated to those of the bare soil surface (PERMANOVA, R2 = 0.187, p = 0.001), indicating that Tillandsia plants host a specific bacterial community, not only dust-deposited cells. Moreover, the bacterial communities in the phyllosphere were distinct from those in the laimosphere, i.e., on buried shoots (R2 = 0.108, p = 0.001), indicating further habitat differentiation within plant individuals. The bacterial taxa detected in the phyllosphere are partly well-known phyllosphere colonizers, but in addition, some rather unusual taxa (subgroup2 Acidobacteriae, Acidiphilum) and insect endosymbionts (Wolbachia, "Candidatus Uzinura") were found. The laimosphere hosted phyllosphere-associated as well as soil-derived taxa. The phyllosphere bacterial communities showed biogeographic patterns across the desert (R2 = 0.331, p = 0.001). These patterns were different and even more pronounced in the laimosphere (R2 = 0.467, p = 0.001), indicating that different factors determine community assembly in the two plant compartments. Furthermore, the phyllosphere microbiota underwent temporal changes (R2 = 0.064, p = 0.001). CONCLUSIONS: Our data demonstrate that T. landbeckii plants host specific bacterial communities in the phyllosphere as well as in the laimosphere. Therewith, these plants provide compartment-specific refugia for microbial life in hyperarid desert environments. The bacterial communities show biogeographic patterns and temporal variation, as known from other plant microbiomes, demonstrating environmental responsiveness and suggesting that bacteria inhabit these plants as viable microorganisms. Video Abstract.

Epiphytic CAM bromeliads indicate vulnerability of tropical forest communities to climate change.

BACKGROUND AND SCOPE: Vascular epiphytes have a variety of mechanisms to trap and retain water, including crassulacean acid metabolism (CAM). Niche segregation was investigated for epiphytic bromeliads on the tropical Caribbean island of Trinidad, where habitats range from lowland deciduous forests to high-rainfall montane tropical forests, ~1000 m in elevation. METHODS: Four tank-impounding bromeliad epiphytes in the genus Aechmea (Ae. aquilega, Ae. fendleri, Ae. nudicaulis and Ae. dichlamydea) with CAM were mapped across their distinct geographical and elevational zonations in northern Trinidad and Tobago. Species distribution modelling was used to determine environmental limitations for each species. Anatomical and physiological measurements included leaf succulence traits, gas exchange and CAM activity; hydraulic conductance and vulnerability; stomatal sensitivity and quantum yield responses to nocturnal temperature and long-term water deficits. KEY RESULTS: A total of 2876 field observations identified the transitions between the lowland Ae. aquilega and montane Ae. fendleri, occurring >500 m a.s.l. at the drier western end of the Northern Mountain Range and at progressively lower elevations towards the wetter, eastern region. Anatomical and physiological sensitivities of gas exchange, CAM activity and water use, and responses to elevated nocturnal temperatures and drought, were markedly different for Ae. fendleri compared with Ae. aquilega or the ubiquitous Ae. nudicaulis. CONCLUSIONS: The species distribution model highlighted the susceptibility of Ae. fendleri to a changing climate. For each species, physiological and anatomical traits were tailored to environmental tolerances, consistent with specialist or generalist niche preferences. Using Intergovernmental Panel on Climate Change scenarios, we predict that rapid rainfall and temperature changes will lead to the loss of Ae. fendleri and associated lower (and upper) montane forest communities from Trinidad, seriously impacting both biodiversity and critical ecosystem functions here and in other tropical island habitats. Epiphytic bromeliads act as markers for threatened communities, and their physiological tolerances represent key indicators of climate change impacts.

An overview of secretion in floral bracts of Tillandsioideae (Bromeliaceae), with emphasis on the secretory scales.

Bromeliaceae display many water-use strategies, from leaf impounding tanks to Crassulacean acid metabolism (CAM) photosynthesis and absorbing trichomes. Recent studies show that trichomes in inflorescences of bromeliads can exude viscous secretions, protecting against various stresses, including excessive water loss. In light of this, and considering the knowledge gap regarding inflorescence trichomes in bromeliads, we aimed to investigate the presence, source and chemical nature of inflorescence secretions in species of the Tillandsioideae (Bromeliaceae) and to describe the anatomy of their floral bracts focusing on trichome structure and position. We conducted a prospection of secretory activity and anatomy in floral bracts in 52 species of Tillandsioideae and 1 early divergent Bromeliaceae species. We used histochemical tests to investigate the presence and nature of secretion combined with standard light microscopy methods. Secretion appears in all studied species of tribe Vrieseeae, in Guzmania species, Wallisia cyanea, Tillandsia streptopylla (Tillandsieae) and Catopsis morreniana (Catopsideae). It is absent in Vriesea guttata (Vrieseeae), Racinaea crispa and various Tillandsia species (Tillandsieae). Secretion is produced by peltate trichomes on the adaxial surface of young bracts and comprises hydrophilic and lipophilic substances. Bract anatomy revealed an internal mucilage-secreting tissue with wide distribution within the subtribe Vrieseinae. Our results point to a broad occurrence of secretion associated with bracteal scales in inflorescences of Tillandsioideae. Secretory function is strongly related to trichomes of the adaxial surface, whereas the indumentum of the abaxial side is lacking or likely associated with water absorption; the latter case is especially related to small, xeric plants. Exudates might engage in colleter-like roles, protecting against desiccation, high-radiation and herbivores. Directions for future research are presented.

Exploring the mycobiota of bromeliads phytotelmata in Brazilian Campos Rupestres.

The phytotelmata is a water-filled tank on a terrestrial plant, and it plays an important role in bromeliad growth and ecosystem functioning. Even though previous studies have contributed to elucidate the composition of the prokaryotic component of this aquatic ecosystem, its mycobiota (fungal community) is still poorly known. In the present work, ITS2 amplicon deep sequencing was used to examine the fungal communities inhabiting the phytotelmata of two bromeliads species that coexist in a sun-exposed rupestrian field of Southeastern Brazil, namely Aechmea nudicaulis (AN) and Vriesea minarum (VM). Ascomycota was the most abundant phylum in both bromeliads (57.1 and 89.1% in AN and VM respectively, on average), while the others were present in low abundance (< 2%). Mortierellomycota and Glomeromycota were exclusively observed in AN. Beta-diversity analysis showed that samples from each bromeliad significantly clustered together. In conclusion, despite the considerable within-group variation, the results suggested that each bromeliad harbor a distinct fungi community, what could be associated with the physicochemical characteristics of the phytotelmata (mainly total nitrogen, total organic carbon, and total carbon) and plant morphological features.

Acid waters in tank bromeliads: Causes and potential consequences.

PREMISE: The consequences of acidity for plant performance are profound, yet the prevalence and causes of low pH in bromeliad tank water are unknown despite its functional relevance to key members of many neotropical plant communities. METHODS: We investigated tank water pH for eight bromeliad species in the field and for the widely occurring Guzmania monostachia in varying light. We compared pH changes over time between plant and artificial tanks containing a solution combined from several plants. Aquaporin transcripts were measured for field plants at two levels of pH. We investigated relationships between pH, leaf hydraulic conductance, and CO2 concentration in greenhouse plants and tested proton pump activity using a stimulator and inhibitor. RESULTS: Mean tank water pH for the eight species was 4.7 ± 0.06 and was lower for G. monostachia in higher light. The pH of the solution in artificial tanks, unlike in plants, did not decrease over time. Aquaporin transcription was higher for plants with lower pH, but leaf hydraulic conductance did not differ, suggesting that the pH did not influence water uptake. Tank pH and CO2 concentration were inversely related. Fusicoccin enhanced a decrease in tank pH, whereas orthovanadate did not. CONCLUSIONS: Guzmania monostachia acidified its tank water via leaf proton pumps, which appeared responsive to light. Low pH increased aquaporin transcripts but did not influence leaf hydraulic conductance, hence may be more relevant to nutrient uptake.

Origin and Function of Amino Acids in Nectar and Nectaries of Pitcairnia Species with Particular Emphasis on Alanine and Glutamine.

Floral nectar contains sugars and numerous other compounds, including amino acids, but little is known about their function and origin in nectar. Therefore, the amino acid, sugar, and inorganic ion concentrations, as well as the activity of alanine aminotransferase (AlaAT) and glutamine synthetase (GS) in nectar, nectaries, and leaves were analyzed in 30 Pitcairnia species. These data were compared with various floral traits, the pollinator type, and the phylogenetic relationships of the species to find possible causes for the high amino acid concentrations in the nectar of some species. The highest concentrations of amino acids (especially alanine) in nectar were found in species with reddish flowers. Furthermore, the concentration of amino acids in nectar and nectaries is determined through analyzing flower color/pollination type rather than phylogenetic relations. This study provides new insights into the origin of amino acids in nectar. The presence of almost all amino acids in nectar is mainly due to their transport in the phloem to the nectaries, with the exception of alanine, which is partially produced in nectaries. In addition, active regulatory mechanisms are required in nectaries that retain most of the amino acids and allow the selective secretion of specific amino acids, such as alanine.

Comparative analyses of the metabolite and ion concentrations in nectar, nectaries, and leaves of 36 bromeliads with different photosynthesis and pollinator types.

Floral nectar contains mainly sugars as well as smaller amounts of amino acids and further compounds. The nectar composition varies between different plant species and it is related to the pollination type of the plant. In addition to this, other factors can influence the composition. Nectar is produced in and secreted from nectaries. A few models exist to explain the origin of nectar for dicotyl plant species, a complete elucidation of the processes, however, has not yet been achieved. This is particularly true for monocots or plant species with CAM photosynthesis. To get closer to such an elucidation, nectar, nectaries, and leaves of 36 bromeliad species were analyzed for sugars, starch, amino acids, and inorganic ions. The species studied include different photosynthesis types (CAM/C3), different pollination types (trochilophilous/chiropterophilous), or different live forms. The main sugars in nectar and nectaries were glucose, fructose, and sucrose, the total sugar concentration was about twofold higher in nectar than in nectaries, which suggests that sugars are actively transported from the nectaries into the nectar. The composition of amino acids in nectar is already determined in the nectaries, but the concentration is much lower in nectar than in nectaries, which suggests selective retention of amino acids during nectar secretion. The same applies to inorganic ions. Statistical analyses showed that the photosynthesis type and the pollination type can explain more data variation in nectar than in nectaries and leaves. Furthermore, the pollinator type has a stronger influence on the nectar or nectary composition than the photosynthesis type. Trochilophilous C3 plants showed significant correlations between the nitrate concentration in leaves and the amino acid concentration in nectaries and nectar. It can be assumed that the more nitrate is taken up, the more amino acids are synthesized in leaves and transported to the nectaries and nectar. However, chiropterophilous C3 plants show no such correlation, which means that the secretion of amino acids into the nectar is regulated by further factors. The results help understand the physiological properties that influence nectaries and nectar as well as the manner of metabolite and ion secretion from nectaries to nectar.

Pitcairnia y Deuterocohnia (Bromeliaceae: Pitcairnoideae) del departamento de Lambayeque, Perú / Pitcairnia and Deuterocohnia (Bromeliaceae: Pitcairnioideae) from Lambayeque, Peru

Resumen Este estudio proporciona una lista comentada de las especies de Pitcairnioideae (Bromeliaceae) del departamento de Lambayeque, Perú. Se reporta un total de cinco especies, una de ellas por primera vez para la zona de estudio y dos representan endemismos norperuanos. Las ecoregiones donde se encuentran corresponden al Desierto Cálido Tropical (DCT), Bosque Seco estacional (BSe), la transición Matorral Desértico-Bosque Seco (MD-BS) y el Bosque Pluvial Montano del Noroeste (BPMN), en las tres provincias del departamento. Se discuten las razones de endemismos, amenazas y criterios de categorización de estas.

Abstract This study provides an annotated list of the species of Pitcairnioideae (Bromeliaceae) from Lambayeque, Peru. A total of five species are reported, one of them for the first time for the study area and two represent northern Peruvian endemisms. The ecoregions where they are found correspond to the Tropical Warm Desert (DCT), Seasonal Dry Forest (BSe), the Desert Scrub-Dry Forest transition (MD-BS) and the Northwest Montane Pluvial Forest (MNPF), in the three provinces of the department. The reasons for endemism, threats and criteria for their categorization are discussed.

Different plant compartments, different yeasts: The example of the bromeliad phyllosphere.

The plant phyllosphere is one of the largest sources of microorganisms, including yeasts. In bromeliads, the knowledge of yeasts is dispersed and still incipient. To understand the extent of our knowledge of the subject, this review proposes to compile and synthesize existing knowledge, elucidating possible patterns, biotechnological and taxonomic potentials, bringing to light new knowledge, and identifying information gaps. For such, we systematically review scientific production on yeasts in bromeliads using various databases. The results indicated that the plant compartments flowers, fruits, leaves, and water tank (phytotelma) have been studied when focusing on the yeast community in the bromeliad phyllosphere. More than 180 species of yeasts and yeast-like fungi were recorded from the phyllosphere, 70% were exclusively found in one of these four compartments and only 2% were shared among all. In addition, most of the community had a low frequency of occurrence, and approximately half of the species had a single record. Variables such as bromeliad subfamilies and functional types, as well as plant compartments, were statistically significant, though inconclusive and with low explanatory power. At least 50 yeast species with some biotechnological potentials have been isolated from bromeliads. More than 90% of these species were able to produce extracellular enzymes. In addition, other biotechnological applications have also been recorded. Moreover, new species have been described, though yeasts were only exploited in approximately 1% of the existing bromeliads species, which highlights that there is still much to be explored. Nevertheless, it appears that we are still far from recovering the completeness of the diversity of yeasts in this host. Furthermore, bromeliads proved to be a good ecological model for prospecting new yeasts and for studies on the interaction between plants and yeasts. In addition, the yeast community diverged among plant compartments, establishing bromeliads as a microbiologically complex and heterogeneous mosaic.

Speciation with gene flow between two Neotropical sympatric species (Pitcairnia spp.: Bromeliaceae).

The study of mechanisms that generate new species is considered fundamental for broad areas of ecology and evolution. Speciation is a continuous process in which reproductive isolation is established, and it is of fundamental importance to understand the origins of the adaptations that contribute to this process. Hybrid zones are considered natural laboratories for the study of speciation and represent ideal systems for such studies. Here, we investigated genomic differentiation between hybridizing Neotropical species Pitcairnia staminea (G. Lodd.) and P. albiflos (Herb.). Using thousands of SNPs genotyped through RAD-seq, we estimate effective population sizes, interspecific gene flow, as well as time of divergence between these two sister species and identify candidate genomic regions for positive selection that may be related to reproductive isolation. We selected different scenarios of speciation and tested them by using approximate Bayesian computation (ABC); we found evidence of divergence with gradual reduction in gene flow between these species over time, compatible with the hypothesis of speciation with gene flow between these Pitcairnia species. The parameter estimates obtained through ABC suggested that the effective population size of P. albiflos was around three times larger than that of P. staminea. Our divergence date estimates showed that these two species diverged during the Pliocene (4.7 Mya; CI = 1.3-8.5 Mya), which has likely allowed this species to accumulate genome-wide differences. We also detected a total of 17 of 4165 loci which showed signatures of selection with high genetic differentiation (F ST > 0.85), 12 of these loci were annotated in de novo assembled transcriptomes of both species, and 4 candidate genes were identified to be putatively involved in reproductive isolation. These four candidate genes were previously associated with the function of pollen development, pollen tube germination and orientation, abiotic stress, and flower scent in plants, suggesting an interplay between pre- and postpollination barriers in the evolution of reproductive isolation between such species.

Influence of Luminosity on Functional Attributes of Quesnelia quesneliana (Brongn.) L.B.Sm. / Influência da Luminosidade nos Atributos Funcionais em Quesnelia quesneliana (Brongn.) L.B.Sm.

Quesnelia quesneliana is an endemic species from Brazil with restricted distribution in restinga areas and has been suffering from changes in its habitat. This study aimed to evaluate the influence of light on the morpho-anatomy and pigment content of Q. quesneliana. The samples were collected in the Liberdade neighborhood in São Mateus, Espírito Santo State, Brazil, which is impacted by anthropization. The influence of light was tested comparing individuals completely exposed to it and individuals under shade. For a morphobiometric analysis, 150 individuals were measured for each light condition, and for pigment determination, 10 leaves were used for each light condition. For anatomical analysis, samples were fixed in 50% FAA and transferred to 70 % ethanol solution after 48 hours. Cross sections were made on roots and stems, and transverse and paradermal sections on leaves. It was concluded that individuals exposed to light are smaller, with higher carotenoid content, while shaded individuals are larger, with more succulent and darker leaves due to greater accumulation of chlorophyll. Anatomically, the individual's structure is similar.

Quesnelia quesneliana é endêmica do Brasil com distribuição restrita nas áreas de restinga e vem sofrendo com alterações no seu habitat. O trabalho objetivou avaliar a influência da luminosidade na morfoanatomia e conteúdo de pigmentos foliares de Q. quesneliana. As amostras foram coletadas no bairro Liberdade em São Mateus, Estado do Espírito Santo, Brasil, que sofre com ações antrópicas. A influência das condições de luminosidade foi testada comparando indivíduos completamente expostos à luminosidade e à sombra. Para as análises morfobiométricas foram mensurados 150 indivíduos por condição luminosa, e para a determinação de pigmentos, foram utilizadas 10 folhas por condição luminosa. Para a análise anatômica, as amostras foram armazenadas em FAA 50 para fixação e transferidas para etanol 50% após 48 horas. Foram realizadas secções transversais em raízes e caules, e secções transversais e paradérmicas em folhas. Conclui-se que os indivíduos expostos a luminosidade são menores, com maior teor de carotenoides, enquanto os indivíduos sombreados são maiores, com folhas mais suculentas e escuras devido ao maior acúmulo de clorofila. Anatomicamente, a estrutura dos indivíduos é similar.

The complete chloroplast genome of Ananas comosus var. erectifolius (L.B. Smith) Coppens & Leal.

Ananas comosus var. erectifolius (L.B. Smith) Coppens & Leal, a tropical plant from Bromeliaceae family, has immense applications, especially for fiber production of excellent quality. The lack of available chloroplast (cp) genome information limits its breeding and application. Here, we assembled its complete cp genome using Illumina high-throughput sequencing technology. The cp genome size is 159,983 bp, with 37.4% GC content, including a large single copy region (LSC) of 87,787 bp, a small single copy region (SSC) of 18,606 bp, and a pair of inverted repeat regions (IRs) of 26,795 bp. It encodes 89 protein-coding, 38 tRNA and 8 rRNA genes. Phylogenetic analysis showed that A. comosus var. erectifolius was close to Ananas comosus. The complete cp genome sequences could provide valuable information for variety breeding and genetic analysis of agronomic and economic traits in A. comosus var. erectifolius.

Seeds cryopreservation of Vriesea reitzii Leme & A.F. Costa endemic bromeliad from Atlantic Rainforest / Criopreservação de sementes de Vriesea reitzii Leme & A.F. Costa bromélia endêmica da Mata Atlântica

Vriesea reitzii is an endemic bromeliad from the Atlantic Rainforest. The objective of this research was to evaluate the cryopreservation using the method of direct immersion of its seeds, collected from capsules at 120, 135, and 150 days after anthesis (DAA). The water content was determined before cryopreservation, while the germination percentage, germination speed index (GSI), and total soluble carbohydrates were quantified after cryopreservation. The highest percentage of moisture (17.6%) was observed in 120 DAA, while the highest percentage of germination (89.6%) and GSI (17.0) were observed in 150 DAA. Optical and transmission electron microscopy analyses were performed, and no cell damage or changes at the morpho-histological and ultrastructural levels were observed after the cryopreservation process. From these results, V. reitzii seeds can be classified as orthodox seeds and the cryopreservation (+LN) is an efficient tool for an ex situ conservation of this species.

Vriesea reitzii é uma bromélia endêmica da Mata Atlântica. O objetivo deste trabalho foi avaliar a criopreservação de sementes utilizando o método de imersão direta, coletadas de cápsulas aos 120, 135 e 150 dias após a antese (DAA). O teor de água foi determinado antes da criopreservação. A porcentagem de germinação, o índice de velocidade de germinação (GSI) e os carboidratos solúveis totais foram quantificados após a criopreservação. A maior porcentagem de umidade (17,6%) foi observada aos 120 DAA, enquanto a maior porcentagem de germinação (89,6%) e GSI (17,0) foram observadas aos 150 DAA. Em análises de microscopia ótica e eletrônica de transmissão não foram observados danos celulares ou alterações a nível morfohistológico e ultraestrutural após o processo de criopreservação. A partir desses resultados, as sementes de V. reitzii podem ser classificadas como ortodoxas e a criopreservação (+LN) é uma ferramenta eficiente para a conservação ex situ desta espécie.