Bamboo Internodes Research Articles

Effects of natural weathering on the mechanical properties of Moso bamboo internodes and nodes

Bamboo structures are susceptible to natural weathering when exposed to outdoor conditions, making it imperative to comprehend the aging resistance of bamboo. In this paper, the study of Moso bamboo exposed to outdoor environment for one year illustrates the discoloration, expansion, mass loss and density reduction of the specimens. The changes of relative crystallinity (CrI) of bamboo were measured by using X-ray diffraction (XRD), the microstructural changes of bamboo were observed by scanning electron microscopy (SEM), and the computed tomography (CT) scanning technology was used to analyze the internal structure of the damaged specimens. Meanwhile, the damage and differences in the mechanical properties of bamboo internodes and nodes were evaluated by the tests of compression parallel to the grain, compression perpendicular to the grain and compressive elastic modulus parallel to the grain, taking into account the bamboo height. The results showed that natural weathering reduces cellulose crystallinity and has a detrimental effect on the cellular structure of bamboo, resulting in a weakening of the interfacial bonding between the vascular bundles and the parenchyma. Consequently, this leads to a decrease in the mechanical properties of bamboo. Compared to the internode specimens, the compressive strength perpendicular to the grain and compressive elastic modulus parallel to the grain are higher in the bamboo node specimens. However, the compressive strength parallel to the grain will be significantly reduced due to the complex fiber structure inside the bamboo nodes. In light of the experimental findings, a constitutive model is proposed to describe the relationship between uniaxial compressive stress and strain in Moso bamboo, both before and after weathering. The numerical results obtained from this model demonstrate a strong correlation with the experimental findings, thereby establishing a solid foundation for conducting finite element analysis on Moso bamboo structures.

Forest Canopy Structures and Bamboo Rhizome Internodes Impact the Appearance Quality of Bamboo Shoots

Bamboo shoots are a healthy vegetable with significant commercial value, and their appearance quality is a key factor influencing consumer preference and market pricing. Their growth characteristics—after being unearthed, they maintain basal diameter while rapidly growing in height—affect the taste and nutritional quality. However, little attention has been given to the impact of bamboo forest management on shoot appearance. Therefore, this study addressed this research gap through a comprehensive investigation across three types of bamboo forests: evergreen broad-leaved forest (EBF), evergreen deciduous broad-leaved mixed forest (MBF), and pure bamboo forest (PBF). In addition, we further assessed factors that potentially affect the appearance quality of bamboo shoots, including canopy structures, understory light factors and understory soil factors, mother bamboo factors, and shoot internal factors (pigments and cells). The basal diameters of shoots in PBF and MBF were 1.89 cm and 1.97 cm, respectively, which were significantly larger than those in EBF by 0.27 cm and 0.35 cm, respectively. The linear mixed effect model identified the number of bamboo rhizome internodes and the chlorophyll a content as primary factors influencing basal diameter thickening and elongation growth of shoots, respectively. In addition, increasing the bamboo canopy and mean leaf angle reduced the chlorophyll a content and increased the carotenoid content, thereby benefiting the improvement in or maintenance of the taste and quality of shoots. This study highlighted that increasing the number of bamboo rhizome internodes, bamboo canopy, and mean leaf angle is helpful to improve the appearance quality of shoots. These findings offer a scientific foundation for bamboo forest management, contributing to both ecological sustainability and economic benefits.

Effects of moisture content and fibrous structure on the uniaxial compression behavior of natural bamboo

The compression properties of natural bamboo were tested, and the crush morphologies with different moisture contents and fibrous structure were observed. Real-time acoustic emission (AE) and optical microscope videos captured the compression behaviors. Dry bamboo internodes showcased 100% higher compression strength with shearing as the predominant failure mode, while the wet samples demonstrated delamination and splitting. AE and fracture morphology indicated five compression behavior categories. Bamboo node samples exhibited heightened compressive strength and modulus than internodes due to their coarser 3D fibrous structures. This investigation offers valuable insights for the development of engineering bamboo materials.

Change in the faunal composition of mosquitoes (Diptera: Culicidae) along a heterogeneous landscape gradient in the Brazilian Amazon.

This study aimed to evaluate the influence of different anthropic landscape profiles on the diversity and distribution of mosquito species in a rural settlement of the Brazilian Amazon. Eight field collections were conducted at 18 sampling points interspersed throughout 2020-2021. Plastic containers, bamboo internodes, and tires were used as traps to capture immature mosquitoes in three distinct habitats: forest, forest edge, and peridomicile. A total of 15,547 individuals, distributed in 26 species of culicids, were collected. The most abundant species were Culex urichii (8,376 specimens), Culex (Melanoconion) (2,473 specimens), and Aedes albopictus (1,252 specimens). Forest habitat showed the highest abundance, and forest edge showed the highest species richness. Different types of environments influenced both the abundance and richness of mosquitoes. The species composition was also significantly different between the analyzed sites, mainly between forest and peridomicile environments. The change in species dominance could largely explain this change in mosquito community composition. Haemagogus janthinomys, an important sylvatic arbovirus vector, was found in peridomicile habitats and Ae. albopictus, a vector associated with human environments, was found in forest habitats, thus providing evidence of species spillover. Our results indicated that landscape changes affect mosquito communities, influencing their richness and abundance. These changes may have implications for future arboviral outbreaks in this rural settlement due to the possible establishment of sylvatic vector species in anthropic environments.

Genome-Wide Identification, Expansion, Evolution, and Expression Analysis Reveals ABCB Genes Important for Secondary Cell Wall Development in Moso Bamboo (Phyllostachys edulis)

The ATP-binding cassette subfamily B (ABCB) is an important transporter family, and many members are well known for their auxin transport function. However, reports on the function of the ABCB genes during Moso bamboo development are few. In this study, we identified and characterized 37 PhABCB genes in Moso bamboo and classified them into five subgroups, Ⅰ–Ⅴ. We further observed gene family expansion and gene loss events during the evolution of the PhABCB gene family. It was found that the expansion of the PhABCB family was mainly attributed to the whole-genome duplication and DNA-transposed duplication models. Gene co-expression analysis and quantitative real-time PCR revealed that several PhABCB genes may be involved in the development of the secondary cell wall (SCW) during the rapid growth of Moso bamboo. Through examining their expression in different parts of the bamboo internode where the cell walls exhibited different developmental stages, the roles of eight candidate PhABCBs in the SCW development were further characterized. Of the eight PhABCB genes, PhABCB7, PhABCB11, PhABCB14, and PhABCB21 may be involved in the SCW biogenesis in Moso bamboo. This study provides the basis for discovering the potential role of PhABCB genes in Moso bamboo cell wall development; further studies are needed to elucidate how these PhABCBs function in SCW development by regulating the polar transport of auxin.

Integrative analysis of exogenous auxin mediated plant height regulation in Moso bamboo (Phyllostachys edulis)

Auxin is important in regulating bamboo growth and development. Morphological and anatomical analyses of naturally growing Moso bamboo treated with auxin revealed that auxin-mediated regulation of bamboo height mainly increased internode length rather than nodes number. For individual internodes, auxin regulated internode elongation mainly by promoting cell elongation. Targeted metabolomic assays of endogenous hormones found that exogenous auxin treatment affected the dynamic balance of endogenous hormones, resulting in increased levels of gibberellin and cytokinin. Transcriptome sequencing indicated that the regulation of internode length by auxin is mainly through phytohormone signaling pathway, amino acid synthesis and protein processing pathway, and energy metabolism pathway. The transcription factors that play major regulatory roles included the ethylene response factor, WRKY and MYB transcription factor, NAC structural domain protein and basic leucine zipper protein. By constructing a gene regulatory network, we found that auxin may crosstalk with multiple plant hormones. Yeast two-hybrid and transgenic experiments demonstrated that the auxin signaling factor PheAUX/IAA34 and the jasmonic acid signaling factor PheTIFY28 do interact and regulate growth in response to phytohormones. Overall we have obtained good quality bamboo internode material for industry through the auxin treatment and have preliminarily investigated the mechanism, which will provide a reference for bamboo plant height regulation.

The “Oxygen Sink” of Bamboo Shoots Regulates and Guarantees the Oxygen Supply for Aerobic Respiration

The amazingly rapid growth of bamboo shoots requires strong respiration and provides a large amount of energy and intermediate metabolites. Strong aerobic respiration requires a large amount of O2. This raises the following question: What is the source and mechanism of O2 supply to meet aerobic respiration? However, currently, this remains unknown. The underground buds (US), the 2-m-high overground buds (AS), and the 8-m-high growth arrest buds (HS) of bamboo (Phyllostachys prominens) were collected to represent their different stages of growth and development. The fifth bamboo shoot node at each stage was sealed by two membranes, and treated in a polyethylene zip-lock bag filled with air (21% O2 + 79% N2) and nitrogen (100% N2) for 1.5 h. The concentrations of free O2 and CO2 in the shoot cavities in polyethylene zip-lock bags, and the ethanol content in the shoot body before and after treatment were determined. In addition, the photosynthetic rates of the fifth bamboo internodes of 1 y/o, 2 y/o and 3 y/o bamboo in the field were measured. The results indicated that: (1) When treated with air and nitrogen, US, AS and HS mainly exhibited aerobic respiration, and there was almost no anaerobic respiration; (2) When treated with air, 59.66%, 54.47% and 45.84% of the O2 in the aerobic respiration of US, AS and HS came from the polyethylene zip-lock bag, 0.06%, 0.57% and 0.650% came from the shoot cavity, but 40.28%, 44.96% and 53.51% of the O2 was of an unknown source; (3) Treated by nitrogen, 0.19%, 4.71% and 4.79% of O2 in aerobic respiration of US, AS and HS came from shoot cavity, while the other 99.808%, 95.290% and 95.21% of O2 came from unknown sources; and (4) The photosynthesis of the fifth internodes of 1 y/o, 2 y/o and 3 y/o bamboo generated little oxygen that could not absolutely meet the huge O2 supply for aerobic respiration. It was concluded that the respiration of P. prominens shoots in its different growth and development stages was dominated by aerobic respiration. O2 supply pathways were mainly via the sheath stomata; however, there was little absorption from dissolved O2 in the soil water and little supply produced by shoot/stem photosynthesis. It was found that the large supply of oxygen in the aerobic respiration of bamboo shoots and young bamboo was of an unknown source under air treatment and nitrogen treatment, i.e., 40.28%–53.51% and 95.21%–99.81% of oxygen in the aerobic respiration of bamboo shoots and young bamboo was of unknown origin, respectively. Therefore, we proposed that bamboo shoots may exhibit the phenomenon of acting as an “oxygen sink”, which can provide a large amount of O2 from unknown sources to ensure the rapid growth of bamboo shoots and young bamboo.

Plasticity in the Morphology of Growing Bamboo: A Bayesian Analysis of Exogenous Treatment Effects on Plant Height, Internode Length, and Internode Numbers.

Sucrose (Suc) and gibberellin (GA) can promote the elongation of certain internodes in bamboo. However, there is a lack of field studies to support these findings and no evidence concerning how Suc and GA promote the plant height of bamboo by regulating the internode elongation and number. We investigated the plant height, the length of each internode, and the total number of internodes of Moso bamboo (Phyllostachys edulis) under exogenous Suc, GA, and control group (CTRL) treatments in the field and analyzed how Suc and GA affected the height of Moso bamboo by promoting the internode length and number. The lengths of the 10th-50th internodes were significantly increased under the exogenous Suc and GA treatments, and the number of internodes was significantly increased by the exogenous Suc treatment. The increased effect of Suc and GA exogenous treatment on the proportion of longer internodes showed a weakening trend near the plant height of 15-16 m compared with the CTRL, suggesting that these exogenous treatments may be more effective in regions where bamboo growth is suboptimal. This study demonstrated that both the exogenous Suc and GA treatments could promote internode elongation of Moso bamboo in the field. The exogenous GA treatment had a stronger effect on internode elongation, and the exogenous Suc treatment had a stronger effect on increasing the internode numbers. The increase in plant height by the exogenous Suc and GA treatments was promoted by the co-elongation of most internodes or the increase in the proportion of longer internodes.

Sesame Oil Addition to Bamboo Reinforced Composite Matrix

Wooden ships use jati wood. Over time jati wood has become scarce. So that jati wood is relatively expensive. therefore bamboo is researched starting from the skin, bamboo meat, and bamboo internodes contained in the plant. In the structure of bamboo there are internodes. The bamboo segment is the weakness of the bamboo structure. The effect of bamboo segments in composite construction was investigated. Sesame oil replaces mineral oil and chemicals, because sesame oil is biodegradable, non-toxic, environmentally friendly, and renewable. To determine the effect of bamboo segments, tensile and bending tests will be conducted on the bamboo composite. The results of this research are expected to find alternative materials, namely bamboo fibre-based composites or so-called bamboo reinforcement plastics (BRP) as materials for making people's ships. This study found that the more layers of bamboo and bamboo segments are very influential in influencing the tensile and bending strength of a laminated material. The tensile testing value of layer 3 with segments reached 127.556 Mpa and without segments 933.333 as well as bending testing layer 3 with segments reached 113.889 Mpa and without segments 111.111 Mpa. From this value, the value has not met the standard of the Indonesian Classification Bureau (BKI).

Adaptation of a wood theoretical fracture model for predicting splitting capacity of dowelled connections in bamboo

A theoretical fracture model for predicting the splitting capacity of transversely loaded dowelled connections in timber was adapted to suit round bamboo. Existing experimental data obtained from a bespoke dowelled connection test for G. angustifolia (Guadua) bamboo was used to validate the model. It was found that the proposed theoretical model corresponds well with the experimental results. In addition, a simple numerical model was implemented using the Finite Element method to model the splitting capacity of the studied connection. The numerical results were found to correlate well with the experimental data. The study confirmed that the splitting capacity of transversely loaded dowelled connections in natural, unfilled bamboo internode can be effectively predicted with a theoretical timber fracture model as well as with the Finite Element analysis. The main outcome of the study is the characteristic equation for splitting capacity of a dowelled connection loaded perpendicular to fibre in round, unfilled Guadua bamboo.

Assembling microbial communities: a genomic analysis of a natural experiment in neotropical bamboo internodes.

Microbes participate in ecological communities, much like multicellular organisms. However, microbial communities lack the centuries of observation and theory describing and predicting ecological processes available for multicellular organisms. Here, we examine early bacterial community assembly in the water-filled internodes of Amazonian bamboos from the genus Guadua. Bamboo stands form distinct habitat patches within the lowland Amazonian rainforest and provide habitat for a suite of vertebrate and invertebrate species. Guadua bamboos develop sealed, water-filled internodes as they grow. Internodes are presumed sterile or near sterile while closed, but most are eventually opened to the environment by animals, after which they are colonized by microbes. We find that microbial community diversity increases sharply over the first few days of environmental exposure, and taxonomic identity of the microbes changes through this time period as is predicted for early community assembly in macroscopic communities. Microbial community taxonomic turnover is consistent at the bacteria phylum level, but at the level of Operational Taxonomic Units (OTUs), internode communities become increasingly differentiated through time. We argue that these tropical bamboos form an ideal study system for microbial community ecology due to their near-sterile condition prior to opening, relatively consistent environment after opening, and functionally limitless possibilities for replicates. Given the possible importance of opened internode habitats as locations of transmission for both pathogenic and beneficial microbes among animals, understanding the microbial dynamics of the internode habitat is a key conservation concern for the insect and amphibian species that use this microhabitat.

Effect of Alkaline 5% NaOH treatment with variations of immersion time on tensile strength and flexural strength of Betung bamboo internode

Betung bamboo has a bigger stem diameter, thicker walls, and shorter internodes than other species of bamboo, making it ideal for building materials such as bridges and interior furnishings that may also be turned into works of art. Alkaline NaOH treatment was introduced to Betung bamboo to increase its mechanical properties. The alkaline treatment used a solution consisting of 5 %NaOH. Specimens with alkaline treatment were immersed into 5%NaOH solution for one hour, two hours, and three hours, followed by two hours of drying in a furnace at 60 °C. Tensile tests (ASTM D638) and flexural tests (ASTM D790) were carried out using servo hydraulics MTS Landmark 100 kN under static loading. The tensile strength, modulus of rupture (MOR) and modulus of elasticity (MOE) were analyzed from the results tests. The average maximum tensile strength of the Betung bamboo internode immersed for two hours into 5%NaOH solution is about 195.95 MPa, whereas the average values of MOR and MOE are about 207.35 MPa and 4.56 GPa, respectively. The faults and surface conditions in the Betung bamboo internode were observed using fractographic and morphological observations.

Mosquito (Diptera: Culicidae) Diversity and Community Structure in Doi Inthanon National Park, Northern Thailand.

Simple SummaryMosquitoes are small flies, some of which are known as principal vectors of the pathogens that cause dengue, malaria, filariasis, chikungunya, Japanese encephalitis, and Zika in many countries of the world. However, the majority of the species are important components of ecosystems. We evaluated the diversity and community structure of mosquitoes in Doi Inthanon National Park, named for the highest mountain in Thailand. The park mainly consists of natural forest, but it hosts a number of human activities. A total of 140 mosquito species were identified among 3,795 specimens. The most dominant genera were Culex (34.3%), Aedes (19.3%), Anopheles (13.6%), Uranotaenia (10.7%), and Armigeres (5.8%). The five most abundant species were Ae. albopictus, Ae. vittatus, Cx. bitaeniorhynchus, Cx. mimulus, and Tripteroides aranoides. Species richness was higher in the rainy season than in the cold and hot seasons. Natural phytotelm habitats for immature stages had a higher diversity than artificial container habitats. A greater number of species were found in forest areas than in agricultural areas and villages. Ground pools, stream pools, rock pools, bamboo stumps, bamboo internodes, and rice fields were the most preferred natural habitats. Ground pools, rock pools, and stream margins, which had a high diversity index, were the most important habitats for mosquitoes in the park.Urbanization and human activities create new suitable aquatic habitats for the immature stages of mosquitoes in many countries. This also applies to Doi Inthanon National Park in northern Thailand, which is named for the highest mountain in the country. Despite its popularity, there is no information regarding mosquito diversity and community structure in the different ecosystems of the park. Monthly collections of immature stages from various habitats were conducted from August 2004 to December 2005 using dipping and sucking methods. The specimens collected from each habitat were reared to adults and identified based on their morphology. Diversity parameters and community structure were statistically analyzed. A total of 140 species (3795 specimens) belonging to 15 genera were identified. Among these, four genera (Culex, Aedes, Anopheles, and Uranotaenia) had high species richness, each represented by 48, 27, 19, and 15 species, respectively. Aedes albopictus was the most relatively abundant species, representing 6.7% of the total number of captured specimens, followed by Tripteroides aranoides (5.6%) and Cx. mimulus (5%). Species richness in natural habitats was significantly higher than in artificial containers. Species richness and abundance were highest in the rainy season. In comparison to agricultural areas and villages, mosquito diversity was found to be higher in forest areas. Ground pools, stream pools, rock pools, bamboo stumps, bamboo internode, and rice fields were the most preferred natural habitats. The results indicate that Doi Inthanon National Park has a high mosquito diversity. Each species exhibits differences in abundance and distribution in different habitats, which is useful information for planning conservation measures and vector control in the park.

Cellular differentiation, hormonal gradient, and molecular alternation between the division zone and the elongation zone of bamboo internodes.

Bamboo differentiates a cell division zone (DZ) and a cell elongation zone (EZ) to promote internode elongation during rapid growth. However, the biological mechanisms underlying this sectioned growth behavior are still unknown. Using histological, physiological, and genomic data, we found that the cell wall and other subcellular organelles such as chloroplasts are more developed in the EZ. Abundant hydrogen peroxide accumulated in the pith cells of the EZ, and stomata formed completely in the EZ. In contrast, most cells in the DZ were in an undifferentiated state with wrinkled cell walls and dense cytoplasm. Hormone detection revealed that the levels of gibberellin, auxin, cytokinin, and brassinosteroid were higher in the DZ than in the EZ. However, the levels of salicylic acid and jasmonic acid were higher in the EZ than in the DZ. Transcriptome analysis with qRT-PCR quantification revealed that the transcripts for cell division and primary metabolism had higher expression in the DZ, whereas the genes for photosynthesis, cell wall growth, and secondary metabolism were dramatically upregulated in the EZ. Overexpression of a MYB transcription factor, BmMYB83, promotes cell wall lignification in transgenic plants. BmMYB83 is specifically expressed in cells that may have lignin deposits, such as protoxylem vessels and fiber cells. Our results indicate that hormone gradient and transcriptome reprogramming, as well as specific expression of key genes such as BmMYB83, may lead to differentiation of cell growth in the bamboo internode.

Mosquitoes (diptera: culicidae) in bamboo internodes in the northwestern region of the state of Rio Grande do Sul, Brazil

Bamboo internodes can serve as a breeding ground for a diverse mosquito fauna, some with relative epidemiological importance. The goal of this study is to determine the mosquitoes´ species found in the bamboo internodes at the northwestern region of Rio Grande do Sul, Brazil. From September 2016 to August, 2017 immature forms of mosquitoes were collected from bamboos (Bambusa sp.), in the quarterly intervals (ten plants per collection) through 0.5 cm in diameter perforations on 40 internodes sides. After 30 days, the perforated internodes were cut out and their contents were taken to the laboratory where the immature forms of mosquitoes developed to adult stage were identified. A total of 367 immature forms of Culicidae were collected, however only 158 (43.1%) have developed to adult stage and were identified at a specific level. Eight species were identified: Onirium personatum (Lutz, 1904), Sabethes aurescens (Lutz, 1905), Sa. intermedius (Lutz, 1904), Sa. purpureus (Theobald, 1907), Shannoniana fluviatilis (Theobald, 1903), Trichoprosopon pallidiventer (Lutz, 1905), Wyeomyia limai (Lane & Cerqueira, 1942) and Wyeomyia serratoria (Dyar & Nuñez Tovar, 1927). Thus, the study showed the importance of this type of breeding in order to maintain the mosquito fauna in the wild areas in the studied region. The finding of the species On. personatum and Sh. fluviatilis was also reported for the first time in the State. KEY WORDS: Fitotelmata; Onirium; Sabethini; Shannoniana; bamboo; mosquitoes.

Mathematical Expression of Internode Characteristics of Yellow Ampel Bamboo (“Bambusa vulgaris” var. Striata)

Most bamboo research has focused on growth performance, physic-chemical attributes, and biomass estimation. There are few studies on elaborating the biometrics of bamboo, especially in internodes mathematical expression. In this study, we revealed the mathematical expression of bamboo internode along the culm. We used 30 samples of culms and cut each culm by its internodes. A total of 928 sample internodes were measured for the outer diameter, wall thickness, and length of internodes. The findings showed that the mathematical expression for two-dimensional culm morphometric was a two and three-order function. In contrast, the three and four-dimensional culm morphometric were a four-order function. Moreover, the relationship between relative internode number (RIN) and relative internode length (RIL), and relative cumulated internode length (RCIL) showed a third-order function.

Interlaminar fracture property of Moso bamboo strips influenced by fiber distributions in bamboo internode and node

Bamboo is widely used as sustainable bio-composite material in the construction of houses, pavilions, furniture, and bridges, etc. As a unidirectional fibrous composite, it is usually damaged due to the interlaminar crack, which is directly related to the corresponding microstructure. In this study, the different fracture performances between bamboo internode and bamboo node are researched, as well as the fiber distributions in these zones. For the internode specimens, the results show that specimens with higher fiber contents tend to exhibit higher fracture energy than the case of lower fiber contents, so the fracture energy presents the functional gradient characteristics with fiber content. It is mainly because that more longitudinal vascular bundles make the fracture crack more tortuous and ultimately need more fracture energy. Furthermore, the node specimens have much-strengthened fracture performance than internode specimens with the same fiber contents, due to the radial fibers distributing in the bamboo node. The microscopic observation results indicate that the existence of radial vascular bundles causes the fracture process to include multiple damage modes such as interface delamination, vascular bundle pull-out, and crack deflection and finally play the effect of resisting crack propagation.

Integrated Approaches for the Identification of Mosquitoes (Diptera: Culicidae) from the Volcanoes of Central America Physiographic Subprovince of the State of Chiapas, Mexico.

Nowadays, there is a lack of information on the mosquito's fauna and DNA barcoding sequence reference library from many areas in Mexico, including the Volcanoes of Central America physiographic subprovince in the state of Chiapas. Consequently, a survey was undertaken to delineate the mosquito (Diptera: Culicidae) fauna in this region across different seasons using different collecting techniques. All species were identified by morphology and DNA barcoding, and their ecological features were also defined. In total, 62 taxa were morphologically examined, 60 of these were successfully identified based on morphological characteristics, but two were unable to be identified at the species level. The genera Aedes, Anopheles, Culex, and Wyeomyia are the most diverse among mosquito genera collected and include several species of medical and veterinary importance. Ecological characteristics of the immature habitats indicated that they were grouped into four categories namely, (1) large water bodies at ground level, (2) small and shady phytotelmata (e.g., tree holes and bamboo internodes), (3) large phytotelmata (e.g., plant leaves and axis bromeliad), and (4) artificial containers. The cytochrome c oxidase subunit I (COI) DNA barcoding sequences successfully separated the majority of these species, although specific species showed >2% intraspecific genetic divergences.

Bionomy of Mosquitoes in Bamboo Internodes in an Atlantic Forest Remnant of the State of Rio De Janeiro, Brazil.

Living bamboo stalks are one of the most specialized habitats for mosquito oviposition and immature development. Most of the mosquito species that breed in these habitats are sylvatic, and some are of importance for public health as possible vectors of pathogens. Perforated internodes are a very specialized environment due to the difficulty of access. Furthermore, due to their relatively simple fauna, they represent a valuable model for ecological studies that may be applicable to more complex environments. This study aims to assess the mosquito bionomics of species raised in bamboo internodes. Therefore, the diversity of mosquito species and the influence of abiotic variables (pH and temperature) on the distribution of mosquitoes that breed in this habitat were analyzed. The study area is a fragment of Atlantic Forest within the Association of da Armada (ATA) in Nova Iguaçu, state of Rio de Janeiro, Brazil. Immature mosquitoes were sampled with suction tubes (mouth aspirators) between August 2017 and July 2018. A total of 3,170 larvae were collected in 5 bamboo plants, each with 8 stalks perforated. Of these, 688 larvae reached the adult stage, representing 10 genera and 19 species. The most common species were Culex neglectus (43%), Trichoprosopon digitatum (22%), Culex iridescens (8%), Sabethes identicus (7%), and Orthopodomyia albicosta (7%). The richness of the immatures collected in the ATA was 19 species, with a diversity of 1.10 and Shannon evenness of 0.57. A diverse composition of Culicidae in bamboo stalks was found, although dominance was low.

Cellular and molecular characterizations of the irregular internode division zone formation of a slow-growing bamboo variant.

The key molecular mechanisms underlying the sectionalized growth within bamboo or other grass internodes remain largely unknown. Here, we genetically and morphologically compared the culm and rhizome internode division zones (DZs) of a slow-growing bamboo variant (sgv) having dwarf internodes, with those of the corresponding wild type (WT). Histological analysis discovers that the sgv has an irregular internode DZ. However, the shoot apical meristems in height, width, outside shape, cell number and cell width of the sgv and the WT were all similar. The DZ irregularities first appeared post apical meristem development, in 1-mm sgv rhizome internodes. Thus, the sgv is a DZ irregularity bamboo variant, which has been first reported in bamboo according to our investigation. Transcriptome sequencing analysis finds that a number of cell wall biogenesis and cell division-related genes are dramatically downregulated in the sgv DZ. Interestingly, both transcriptomic and brassinosteroid (BR) contents detection, as well as quantitative real-time PCR analyses show that these irregularities have resulted from the BR signaling pathway defects. Brassinosteroid defect might also cause the erect leaves and branches as well as the irregular epidermis of the sgv. These results suggest that BR signaling pathway plays critical roles in bamboo internode DZ and leaf development from a mutant perspective and also explain the upstream mechanisms causing the dwarf internode of the sgv bamboo.