Abstract Present work consists of a pioneer taxonomic survey of pseudofilamentous desmids in southern Bahia, Brazil. Based on periphytic and planktonic samples collected from ponds in Serra do Conduru State Park, Uruçuca, Bahia, 24 taxa were identified, including first documented occurrences for South America ( Groenbladia undulata var. kriegeri , Hyalotheca burmensis, and Teilingia excavata ) . Moreover, we present a new combination based on previously unknown morphological data: Hyalotheca confervacea comb. nov., a species that is being currently reported for the second time in Brazil after a 78-year gap. Furthermore, we present for the first time details of zygospores of two taxa ( Hyalotheca mucosa var. laevicincta and Hyalotheca tatrica ). This study contributes to our understanding of pseudofilamentous desmid diversity and distribution in Brazil and South America.
The semiarid landscapes of Northeastern Brazil host disjunct savanna formations, often broadly categorized under the term ‘northeastern cerrados’, whose biogeographical connections with the core Cerrado and Caatinga domains remain debated. While savanna formations on sedimentary basins have been extensively characterized, those established on crystalline substrates remain poorly understood. This study documented the angiosperm flora of a granitic-based savanna on the Serra do Barriga inselberg (Sobral, Ceará, Brazil) and assessed its phytogeographical identity using a comprehensive multivariate suite (UPGMA, NMDS, PCoA, PERMANOVA, PERMADISP, and NODF nestedness), comparing the site with the other 29 areas. We recorded 156 species, with Fabaceae as the most representative family and a predominance of therophytes. Although the area exhibits a typical savanna physiognomy featuring ‘oligarchic’ woody species (e.g., Tabebuia aurea), statistical analyses consistently positioned the site within the Crystalline Caatinga block. Furthermore, the overall biogeographic results revealed a pronounced species turnover, highlighted by an anti-nestedness system (NODF = 11.56, p < 0.01) among the analyzed areas, and demonstrated that the expression ‘northeastern cerrados’ is an inaccurate generalization, as these patches function as heterogeneous transitional mosaics rather than a cohesive floristic group. For the Serra do Barriga vegetation, the decoupling of structure and composition indicates that the shallow crystalline substrate acts as a primary environmental filter selecting for Caatinga taxa, while local ‘run-off’ mechanisms allow the persistence of savanna elements. Given its distinct identity and role as a refuge for threatened taxa (e.g., Bacopa cochlearia, Amburana cearensis), the creation of a Natural Monument is recommended to protect this singular ecosystem.
Croton urucurana is a pioneer species used in soil regeneration and traditional medicine. Despite expectations of adaptive variation across its extensive range, the species’ macro-geographic genetic structure and its relationship with phenotypic traits are still poorly understood. To address this knowledge gap and identify critical evolutionary reservoirs, this study integrated molecular, anatomical, and palynological data to evaluate diversity across the Chaco, Amazon, Cerrado, and Atlantic Forest domains. Twenty-nine specimens were analyzed using Light and Scanning Electron Microscopy, in parallel to DNA analysis, to assess genetic structure. The study identified two distinct genetic lineages. Brazil exhibited the highest genetic diversity, containing representatives of both lineages. Argentina showed the lowest diversity, composed almost exclusively of a single lineage, whereas Paraguayan samples are distributed between two groups, consistent with a zone of genetic contact and admixture. Molecular variance analysis shows that 94
The firecracker plant Russelia equisetiformis is native to Mexico and introduced worldwide for ornamental gardening and landscaping. This plant is a year-round bloomer with copious red flowers that attract nectar-feeding birds. In the Americas the slender, long-tubed flowers are pollinated by diverse set of small and large hummingbirds, whereas in Australia a small honeyeater with hummingbird-like bill is the only recorded pollinator. Herein we briefly describe and illustrate a medium-sized robust honeyeater visiting the flowers of the firecracker plant. We observed the plant and the honeyeater in suburban Central Coast, Australia. The flowers were visited and probably pollinated by the noisy miner Manorina melanocephala. When the bird inserted its short and robust bill into the flower to extract nectar, the corolla slit longitudinally, while the reproductive structures remained intact despite the altered appearance of the flower. The behaviour displayed by the noisy miner seems to be a previously undescribed interaction and further observations would clarify its functional and ecological implications.
Seed dispersal interactions are critical for the persistence of parasitic plants. However, anthropogenic habitat change may alter those interactions. We examined how anthropogenic habitat transformation in an urban area alters frugivore interactions of the hemiparasitic mistletoe Tristerix corymbosus. While Mimus thenca is traditionally recognized as its primary disperser, rapid urbanization and the replacement of native sclerophyllous vegetation by invasive Acacia species have modified these dynamics. Using focal observations and camera traps, we recorded 181 fruit-consumption events. We found that the herbivorous bird Phytotoma rara accounted for 60
The phenylpropanoid pathway leads to the formation of a wide array of secondary metabolites. In this pathway, the Cinnamate 4-hydroxylase (C4H) gene encodes the enzyme catalyzing the second step of hydroxylation of cinnamic acid into p-coumaric acid. Orchids serve as a rich source of metabolites thus making it significant to analyze the C4Hs in orchids. In the present study, two C4H proteins were identified in each of the orchid species under study (Apostasia shenzhenica, Dendrobium catenatum, Phalaenopsis aphrodite, P. equestris, P. lueddemanniana, P. modesta and P. schilleriana) except in Phalaenopsis bellina which had three C4H proteins. Multiple sequence alignment confirmed the presence of five substrate binding sites, the ERR triad, enzymatic active sites, hinge motif and heme–iron binding domain in all the proteins. Motif analysis showed that the motif encapsulating the p450 domain was present in all the proteins. Secondary structure prediction revealed a prevalence of alpha helices and random coils in the identified proteins. Phylogenetic analysis grouped C4H proteins into two clades, representing class I and II. Gene structural analysis showed the presence of two introns and the promoter study of these genes revealed the presence of cis-acting elements regulated by light, abiotic and biotic stress and plant growth and development. Tissue-specific expression profiling of C4H genes showed varied expression patterns in reproductive and vegetative tissues, suggesting diverse roles in growth and development.
Dyckia brevifolia is a riparian bromeliad endemic to southern Brazil. Despite the endangered status of this species, no genomic resources are available to aid conservation initiatives. This study describes the investigation of the genetic diversity and structure of D. brevifolia populations using newly neutral, species-specific nuclear microsatellite markers developed through genome skimming. Genotyping thirty individuals from three populations with nine generated microsatellite markers revealed low levels of allelic and genetic diversity (A = 2.56 and He = 0.39, Ho = 0.19) and high fixation index (f = 0.46), indicating significant inbreeding levels. Principal coordinates analysis suggested the occurrence of gene flow directed by river current, favoring downstream populations, which evidences hydrochorous dispersal of propagules. These primary data using molecular markers provide the basis for designing conservation strategies to ensure the maintenance of gene flow and genetic variability in the fragmented populations of D. brevifolia.
In this study, embryogenic calluses (EC) of Cinnamomum camphora were used as the initial material and control, and somatic embryos (SE) were used as the material to be tested for transcriptome analysis. By analyzing the expression patterns of genes related to lipid anabolism (fatty acid biosynthesis, fatty acid elongation and triacylglycerol synthesis), the energy storage mechanism during somatic embryogenesis was explored. The transcriptome analysis results of somatic embryos and embryogenic calluses in Cinnamomum camphora revealed a total of 80 differentially expressed genes (DEGs) associated with lipid anabolism, including 56 up-regulated genes and 24 down-regulated genes. Among them, the key genes related to the fatty acid biosynthesis pathway were ACC, KASⅠ/Ⅱ/Ⅲ, and FATA/B. The key gene involved in the fatty acid elongation pathway was KCS. The key genes in the triacylglycerol synthesis pathway were GPAT, DGAT, and PDAT. Through comparison, it was found that there were significant differences in the expression of genes related to the three pathways of lipid anabolism, indicating that the activity of lipid anabolic pathways in embryogenic calluses and somatic embryos was different. Fatty acid biosynthesis, fatty acid elongation, and triacylglycerol synthesis were all more active in the somatic embryos. This study, from the perspective of lipid anabolism, provided a reference for researching energy storage during the somatic embryogenesis process of Cinnamomum camphora.
Fire triggers flowering, stimulating and advancing flower production and, consequently, fruiting in some plants of the Cerrado, the Brazilian savanna. Integrated Fire Management (IFM) has been applied in several protected areas in the Cerrado to simulate natural fire regimes. However, its effects on both flowering and fruiting patterns remain underexplored. This study evaluated the impact of IFM on the phenology and abundance of flowers and fruits of Macairea radula, an abundant shrub that produces large quantities of flowers. Sampling was conducted monthly for 12 months in both unburned and low-intensity prescribed-burned areas. Our findings highlight the complex interactions between fire and plants. Prescribed fire anticipated and extended flowering, indicating that M. radula is fire-stimulated but not fire-dependent. However, fire reduced both the fruiting period and fruit abundance, suggesting an effect on initial reproductive stages that did not lead to increased fruit availability over time. These findings underscore the need to monitor phenological processes beyond flowering. Species-specific assessments are essential for understanding the full impact of IFM on plant reproductive strategies and for guiding fire management in fire-prone biodiversity hotspots. From a management perspective, our results also indicate that adjusting the timing of prescribed fires to avoid periods of high reproductive sensitivity may substantially mitigate negative effects on plant reproductive success without compromising the benefits of low-intensity burns.
Understanding reproductive trait divergence among closely related taxa is essential for deciphering the evolutionary mechanisms of diversification. This study aimed to characterize and compare the reproductive ecology of four endemic Anatolian subspecies of the Jasione supina complex: subsp. akmanii, subsp. pontica, subsp. supina, and subsp. tmolea. We analyzed flowering phenology, floral morphometrics, pollen biology, breeding systems, and pollinator visitation under natural field conditions. Our results demonstrate significant variation in reproductive efficiency across the complex; fertilization success reached 81.97
The critically endangered evergreen tree Elaeocarpus venustus is a specialist of submontane riparian swamps, where it exhibits a singular, synchronous annual phenological cycle driven by climatic cues. Research indicates that its flowering is positively correlated with rainfall but negatively influenced by rising temperatures. While a single individual in a nutrient-rich swamp habitat can command up to 31.8
Palaeobotany can provide insights into the preservation patterns of different plant organs in the fossil record and how diversity was represented across various geographic scales in the Permian palaeoflora. These insights are important for interpreting palaeodiversity and palaeoenvironmental conditions more integratively. Reproductive and vegetative organs may be preserved in systematically different proportions, potentially biasing our understanding of past plant communities and leading to over- or underestimation of diversity depending on the fossils available in different regions, climates, or time intervals. We thus investigate whether vegetative or reproductive elements reported in 37 studies spanning 1945 to 2024 are more abundant in the Permian fossil record and how different geographic scales influence the diversity of these elements. Networks, combined with meta-analyses, were employed to understand the heterogeneity of fossil-taxa composition and certain biogeographic aspects. Our results revealed a higher proportion of vegetative than reproductive parts, with the type of anatomical fragment separating distinct geographic regions at different scales. No evidence of publication bias was detected. Continental-scale analyses favoured vegetative parts, whereas hemisphere-scale patterns favoured reproductive parts. Networks indicated Leiotriletes as a connector taxon and Pecopteris as widely distributed. Antarctica showed the highest palaeobotanical potential, with the greatest diversity of preserved parts. Leaves appeared to increase the taxonomic precision of the recorded fossil-taxa. Arborescent plants may have dominated the physiognomy of milder climates during different Permian epochs. The Late Permian does not appear to have undergone abrupt changes in its palaeofloristic physiognomy when fossil-taxa are considered at the genus level.
Astereae, comprising approximately 252 genera and 3100 species, is the second largest tribe within the family Asteraceae. Members of this tribe are most commonly found in temperate regions. Astereae is considered the sister tribe of Anthemideae. The taxonomy and subtribal classification of the Astereae are challenging and controversial. Consequently, pollen morphology is a practical and reliable tool for studying the systematics of the Astereae due to its conserved features. This study aims to identify and describe the pollen types within Astereae based on pollen features and to investigate the relationships among subtribes, genera and species using these data. The pollen micromorphology of 39 specimens representing 11 genera of Astereae was examined using scanning electron microscopy. Clustering and ordination methods identified three pollen types—Aster, Bellis and Symphyotrichum—among the studied taxa. PCA analysis revealed that the distance between spines was the most important pollen feature for distinguishing the three groups. Therefore, pollen morphology played a reliable role in the delimitation of the studied species within the tribe and identifying the different pollen types. Using the pollen data, the taxonomic problems related to the delimitation between the genera Aster and Erigeron were resolved based on differences in pollen micromorphology. The studied Astereae taxa demonstrated the greatest similarity in pollen features with the tribe Anthemideae, particularly in features such as exine ornamentation and spine size.
Canistrum (Bromeliaceae) comprises 13 species endemic to the Atlantic Forest and is subdivided into two subgenera (Canistrum and Cucullatanthus). This study aimed to characterize the morphology of reproductive structures (pollen and stigma), assess pollen viability and stigma receptivity across all species of the genus, and evaluate the taxonomic, reproductive, and conservation relevance of these characters. Analyses were conducted using light microscopy (with pollen grains prepared by lactic acetolysis) and scanning electron microscopy. Pollen viability was assessed using histochemical tests and in vitro germination assays at three floral stages. Stigma receptivity was evaluated through enzymatic assays. Pollen grains are dispersed as monads and show variation in shape (oblate, suboblate, and oblate-spheroidal), polarity (apolar and subisopolar), amb (circular and elliptical), aperture (pantoporate and biporate), and exine ornamentation, consistently semitectate and reticulate-heterobrochate to foveolate, with differences in lumen structure depending on the presence of granules. The occurrence of distinct pollen types proved informative for infrageneric delimitation within Canistrum. Stigmas are conduplicate-spiral, with stigmatic lobes ranging from crenulate to laciniate, and coloration varying from white to yellow. Pollen viability was high in all species, especially during anthesis, a stage that also showed the highest in vitro germination rates. Stigma receptivity peaked at anthesis and remained high during post-anthesis, indicating synchrony between pollen and stigma and suggesting the absence of dichogamy. Overall, pollen aperture type and exine ornamentation are stable characters of taxonomic value, whereas viability, germination, and receptivity patterns provide insights into reproductive strategies, supporting conservation and reproductive management of endemic and threatened Canistrum species.
This study evaluated the effects of solar UV-B (Ultraviolet-B) radiation on coffee seedlings at different altitudinal ranges in a tropical environment. A field experiment, conducted using a randomized complete block design, tested four coffee varieties—Fayette, Odisha, Koti, and Hangafa—under natural UV-B radiation and UV-B-blocking sheets at altitudes of 1450, 1850, and 2150 m, with three replications. The results revealed that altitude significantly influenced most growth parameters, except for specific leaf area and primary branch girth. The interaction between altitude and coffee variety affected plant height, primary branch length, and internode length (at p < 0.001, 0.01 and 0.05, respectively), with plant height and primary branch length decreasing as altitude increased. Altitude also impacted leaf area and physiological parameters such as photosynthetic rate (Pn) and transpiration rate. In contrast, the interaction of UV-B and altitude influenced stomatal conductance and intercellular CO2 levels. These findings demonstrate that coffee varieties respond differently to solar UV-B radiation at different altitudes. This highlights the need for location-specific coffee breeding/genetic selection/ in tropical environments to address adaptation to climate change, particularly in relation to increased UV radiation.
We investigated the role of Aluminum (Al) as a limiting factor for the development of Borreria latifolia, analyzing morphophysiological changes, subcellular accumulation sites, and its interaction with pH on biomass increment. We evaluated biomass fluctuation under different Al concentrations of 0, 250, 500, and 750 µM, and the combined effect of Al (presence/absence) under pH 3.5, 4.5, or 5.5. The beneficial effects on both root and shoot development were dependent upon both Al concentration and medium pH. The concentration of 750 µM Al at pH 4.5 induced the highest dry mass buildup. In the absence of Al, the pH gradient did not affect plant growth, but the addition of Al (pH 4.5) promoted dry mass increases of 34
Drought is the most prevalent environmental stress in crop production, posing a significant danger to food security. Microorganisms in the crop root zone affect crop growth and development, enhance effective nutrient use, and resist adversity hazards. Our study was to analyze the changes and functional differences of rhizosphere soil communities in sugar beet under drought stress. In this study, the rhizosphere soil of sugar beet were collected and analyzed by high-throughput sequencing and bioinformatics at 7, 14 and 21 days after water control treatment. There were two levels of water control treatment: normal water supply (relative soil water content = 70
Stream macroalgal communities were sampled at 58 sites across four national parks representing highland grasslands in southeastern Brazil. We assessed taxonomic beta diversity and its components (spatial turnover and nestedness), as well as the influence of selected environmental variables. Environmental conditions varied widely among streams from the different parks, reflecting high environmental heterogeneity, a pattern commonly reported for similar ecosystems worldwide. Cyanobacteria predominated in the flora of the four parks (47.4
The interaction between abiotic factors and plant traits is central to ecological strategies and species distribution, especially in environments with climate variability. It is reflected in morphoanatomical and biochemical traits that influence growth and survival. Widely distributed, species-rich families are models for understanding how environmental filters shape plant traits and foster innovation. Bromeliaceae, a diverse Neotropical family, exemplifies this dynamic, bringing together species with multiple habits (epiphytic, rupicolous, saxicolous, and terrestrial) and remarkable morphological diversity. Given Bromeliaceae significance in the Brazilian Atlantic Forest, particularly in high-elevation regions, we investigated environmental parameters potentially influencing trait variation in three widely distributed species: Aechmea vanhoutteana, Pitcairnia carinata, and Quesnelia kautskyi, occurring in distinct areas within Parque Nacional do Caparaó (MG/ES), Brazil. PCA analyses confirmed that temperature, humidity, and light intensity were the primary filters shaping functional trait space, possibly influencing niche differentiation and species coexistence. Aechmea vanhoutteana exhibits a generalist ecological strategy, thriving across all three life habits with minimal morphoanatomical and biochemical content adjustments. Pitcairnia carinata, confined to rocky outcrops, exhibited notable anatomical specializations likely balancing thermal tolerance and water conservation. Quesnelia kautskyi demonstrated the greatest trait variation, particularly between terrestrial and epiphytic individuals, with humidity emerging as the main driver of anatomical and biochemical differences. While morphological traits were relatively stable across conditions and functioned as “effect traits”, anatomical and biochemical traits acted as “response traits”, adjusting dynamically to environmental stimuli. Altogether, the results highlight that morphoanatomical and biochemical plasticity is critical for ecological performance and persistence in heterogeneous montane landscapes. Furthermore, approaches incorporating multiple traits can offer key insights into how environmental pressures potentially drive plant adaptation, specialization, and evolution in Neotropical ecosystems.
The reproductive structures of the family Piperaceae are a subject of debate, primarily because of the high variability in megagametophyte development and the modifications to previous characterizations of final arrangement of the embryo sacs. Information on the reproductive biology and pollination strategies of Peperomia remains limited. This study provides a detailed description of the developmental morphology and floral anatomy of Peperomia bracteata from Pedregal de San Angel, Mexico. We conducted a detailed developmental and anatomical study of P. bracteata inflorescences and flowers using light and scanning electron microscopy with conventional histological and histochemical techniques. Our findings revealed that the flowers are arranged spirally on spikes that mature basipetally. The flowers are perianthless and each is subtended by a bracteole. The androecium consists of two stamens with short, broad filaments, while the gynoecium features a single ovule within a globose ovary, broad style, and capitate stigma. Lipid-secreting osmophores were detected in both the ovary and the style. The embryo sac was tetrasporic and contained 16 nuclei, conforming to the Peperomia-type configuration. This study provides the first comprehensive description of floral morphoanatomy and gametophyte development in a Mexican Peperomia species. Our results provide valuable insights into the structural and embryological diversity of Piperaceae, highlighting the evolutionary relevance of female gametophyte variation and floral specialization in early-diverging angiosperms.
