Leaf Venation Patterns Research Articles

Leaf Venation of Brazilian Species of Cryptocarya R. Br. (Lauraceae)

With the aim of recognizing and identifying both fertile and sterile specimens of Cryptocarya from Brazil, we analyzed the leaf venation pattern of 14 taxa, 6 of them being described and illustrated for the first time. A dichotomous identification key was built from a matrix of 12 leaf venation characters and 30 character states, which distinguishes among taxa.

Venation studies of some species in the genus Ficus Linn. in Southwestern Nigeria

The present study investigates the venation of ten species of the genus Ficus collected from Obafemi Awolowo University Ile-Ife (latitude 7° 31' 14.7612'' N and longitude 4° 31' 49.1340'' E) and the NACGRAB, Ibadan, Nigeria (latitude 7°23¢4²N and longitude 3°50¢31²E). The leaf venations of the species were carried out using standard methods. All photomicrographs of the features were taken with the aid of Amscope digital camera mounted on a celesterone binocular microscope. All data were subjected of analysis of variance using SAS software. The result revealed the Leaf venation pattern based on areole shape, length and width, veinlets ending and trichomes. The leaf venation patterns of the species show that they are significant in identifying and delimiting studied species within the genus with respect to qualitative and quantitative data. Species specific variation were recorded for the venation patterns as areole shape, length and width, veinlets ending and trichomes and these features are either genetically fixed or as a result of environmental extremes. Presence of cystolith cells, trichomes and no veinlets ending is diagnostic of Ficus mucuso. The study concluded that venation patterns are therefore significant in delimitation of species in the genus Ficus and these characters can be employed as additional information in the existing taxonomical keys of the genus.

Leaf venation of Ocotea species (Lauraceae) from Bahia, Brazil

AbstractWith the aim of recognizing and identifying both fertile and sterile specimens of Ocotea from the Brazilian state of Bahia, we analyzed the leaf venation pattern of 55 species, 21 of them being described and illustrated for the first time. A dichotomous identification key was built from a matrix of 12 venation characters and 36 states, which allowed to distinguish the taxa.

Leaf venation of Lauraceae species (excluding Ocotea) from Bahia, Brazil

With the aim of recognizing and identifying both fertile and sterile specimens of Lauraceae from the Brazilian state of Bahia, we analyzed the leaf venation pattern of 56 species belonging to 14 genera (excluding Ocotea), 30 of them described and illustrated for the first time. A dichotomous identification key was built from a matrix of 12 venation characters and 36 states, which allowed to distinguish the taxa.

Leaf venation of Lauraceae species (excluding Ocotea) from the Reserva Natural Vale, Linhares, Espírito Santo, Brazil

ABSTRACTWith the aim of recognizing and identifying both fertile and sterile specimens of Lauraceae from the Reserva Natural Vale, Linhares, we analyzed the leaf venation pattern of 20 species belonging to 11 genera. The venation patterns of 12 species are described and illustrated for the first time here. A dichotomous identification key was built from a matrix of 12 venation characters with 38 states, which allowes to distinguish the taxa.

Leaf venation of Ocotea species (Lauraceae) from the Reserva Natural Vale, Linhares, Espírito Santo, Brazil

With the aim of recognizing and identifying both fertile and sterile specimens of Ocotea from the Reserva Natural Vale, Linhares, we analyzed the leaf venation pattern of 31 species, 13 of them being described and illustrated for the first time. A dichotomous identification key was built from a matrix of 12 venation characters and 36 states, which allowed to distinguish the taxa.

Leaf venation patterns as a model for bioinspired fog harvesting

Collecting water from the atmosphere has been studied to address the global water shortage. One main challenge in this method is designing a patterned surface to maximize the water collection efficiency. In this work, we propose a bioinspired categorization method for the types of surfaces based on leaf venation patterns that are fabricated by direct laser writing. Our method introduces three categories from simple to complex intervals that include: completely linear, a combination of linear and network, and completely networked. Results show that our design-inspired pieces of venations suggest superior performance compared to the simple non-planar surface by boosting the efficiency of about ∼200−400% at the best venation pattern at 60° while making it possible to have enhanced effective and controllable transport of liquid through channels.

Identification of tree species using a machine learning algorithm based on leaf shape and venation pattern

Identification of tree species using a machine learning algorithm based on leaf shape and venation pattern

Auxin transport model for leaf venation.

The plant hormone auxin controls many aspects of the development of plants. One striking dynamical feature is the self-organization of leaf venation patterns which is driven by high levels of auxin within vein cells. The auxin transport is mediated by specialized membrane-localized proteins. Many venation models have been based on polarly localized efflux-mediator proteins of the PIN family. Here, we investigate a modelling framework for auxin transport with a positive feedback between auxin fluxes and transport capacities that are not necessarily polar, i.e. directional across a cell wall. Our approach is derived from a discrete graph-based model for biological transportation networks, where cells are represented by graph nodes and intercellular membranes by edges. The edges are not a priori oriented and the direction of auxin flow is determined by its concentration gradient along the edge. We prove global existence of solutions to the model and the validity of Murray's Law for its steady states. Moreover, we demonstrate with numerical simulations that the model is able connect an auxin source-sink pair with a mid-vein and that it can also produce branching vein patterns. A significant innovative aspect of our approach is that it allows the passage to a formal macroscopic limit which can be extended to include network growth. We perform mathematical analysis of the macroscopic formulation, showing the global existence of weak solutions for an appropriate parameter range.

PHYLOGENY OF TWO AFRICAN GENERA OF SAPOTACEAE – ENGLEROPHYTUM AND SYNSEPALUM

Englerophytum and Synsepalum are two closely related genera of trees and shrubs from the African tropics. Previous molecular studies have shown that these genera collectively form a clade within the subfamily Chrysophylloideae (Sapotaceae). However, little is known about the inter-relationships of the taxa within the Englerophytum–Synsepalum clade. In this study, nuclear ribosomal DNA and plastid trnH–psbA sequences were used to estimate the phylogeny within the clade. Results indicate that the clade consists of six major lineages, two composed solely of taxa from the genus Englerophytum and four composed of taxa from the genus Synsepalum. Each lineage can be distinguished by suites of vegetative and floral characters. Leaf venation patterns, calyx fusion, style length and staminodal structure were among the most useful characters for distinguishing clades. Some of the subclades within the Englerophytum–Synsepalum clade were also found to closely fit descriptions of former genera, most of which were described by Aubréville, that have since been placed in synonymy with Englerophytum and Synsepalum. The clade with the type species of Englerophytum also contains the type species of the genera Wildemaniodoxa and Zeyherella, which are confirmed as synonyms.

Phylogeny and circumscription of Dasyphyllum (Asteraceae: Barnadesioideae) based on molecular data with the recognition of a new genus, Archidasyphyllum.

Dasyphyllum Kunth is the most diverse genus of the South American subfamily Barnadesioideae (Asteraceae), comprising 33 species that occur in tropical Andes, Atlantic Forest, Caatinga, Cerrado, and Chaco. Based on distribution, variation in anther apical appendages, and leaf venation pattern, it has traditionally been divided into two subgenera, namely, Archidasyphyllum and Dasyphyllum. Further, based on involucre size and capitula arrangement, two sections have been recognized within subgenus Dasyphyllum: Macrocephala and Microcephala (=Dasyphyllum). Here, we report a phylogenetic analysis performed to test the monophyly of Dasyphyllum and its infrageneric classification based on molecular data from three non-coding regions (trnL-trnF, psbA-trnH, and ITS), using a broad taxonomic sampling of Dasyphyllum and representatives of all nine genera of Barnadesioideae. Moreover, we used a phylogenetic framework to investigate the evolution of the morphological characters traditionally used to recognize its infrageneric groups. Our results show that neither Dasyphyllum nor its infrageneric classification are currently monophyletic. Based on phylogenetic, morphological, and biogeographical evidence, we propose a new circumscription for Dasyphyllum, elevating subgenus Archidasyphyllum to generic rank and doing away with the infrageneric classification. Ancestral states reconstruction shows that the ancestor of Dasyphyllum probably had acrodromous leaf venation, bifid anther apical appendages, involucres up to 18 mm in length, and capitula arranged in synflorescence.

Leaf architecture of Rubiaceae Juss. from caatinga vegetation in Brazil

Abstract: The study and characterization of leaf venation plays a key role in the recognition of taxonomic groups that have been identified mainly based on reproductive traits. This study aimed at characterizing the pattern of leaf venation of Rubiaceae, recognizing individual characters among the taxa of this group and testing the use of leaf architecture as a taxonomic tool capable of providing vegetative and diagnostically characteristics between species. Leaves of 14 species distributed in eight genera from Rubiaceae were diaphanized and classified. The study area is located in Área de Proteção Ambiental Serra Branca/Raso da Catarina, Bahia State, Brazil. The characterization of secondary veins, including type, spacing and number of pairs, third veining patterns, fourth and fifth order, and the conformation of the areola were useful to delimit taxa when used together, providing subsidies to more comprehensive studies.

Multimodal plant recognition through hybrid feature fusion technique using imaging and non-imaging hyper-spectral data

Automatic classification of the plants is growing area of association with computer science and Botany, it has attracted many researchers to subsidize plant classification using image processing and machine learning techniques. Plants can be classified using number of traits such as leaf color, flowers, leaves, roots, leaf shape, leaf size etc. highly depends upon feature selection methods. However extraction of features from selected trait is most significant state in classification. State-of-the-art classification can be achieved by using leaf characteristics such as leaf venation patterns, leaf spectral signatures, leaf color, leaf shape, etc. This paper describes multimodal plant classification system using leaf venation patterns and its spectral signatures as a significant features. This paper shows that the feature fusion can be used to achieve efficient plant identification. The accuracy of identification for leaf spectral data, leaf venation features and HOG features is validated, it signifies that feature fusion technique performs better than that of non-imaging spectral signatures features only, with recognition result of 98.03% GAR and 93.51% GAR, respectively.

Foliar architecture of some members of the tribe Senecioneae (Asteraceae) with a key for identification of the Mexican genera

The foliar architecture of 18 genera (Barkleyanthus, Digitacalia, Erechtites, Nelsonianthus, Packera, Pentacalia, Pippenalia, Pittocaulon, Psacaliopsis, Psacalium, Pseudogynoxys, Robinsonecio, Roldana, Senecio, Telanthophora, Tetradymia, Villasenoria and Werneria) of the tribe Senecioneae (Asteraceae) distributed in Mexico is described. The aim was to identify leaf characters to be used in the taxonomy and phylogenetics of the tribe, as well as a source to identify at the generic rank the genera distributed in Mexico. More than 400 specimens were revised and several leaves were cleared to analyze leaf venation patterns. Four patterns of primary venation (actinodromous suprabasal, paralelodromous, pinnate and radiate-palmate) and five patterns of secondary venation (brochidodromous, weak-brochidodromous, craspedodromous, mixed-craspedodromous and festooned-semi-craspedodromous) were identified. Terminal tracheids were observed only in veinlets of Pentacalia, Pseudogynoxys and Werneria. In addition, secretory canals and crystals occurred in several genera. Foliar architecture showed to be a useful tool to identify genera, an identification key based mostly on leaf architecture characters is provided.

Morphological variation among fifteen superior robusta coffee clones in Lampung Province, Indonesia

Ramadiana S, Hapsoro D, Yusnita Y. 2018. Morphological variation among fifteen superior robusta coffee clones inLampung Province, Indonesia. Biodiversitas 19: 1475-1481. This study aimed to characterize morphological variation among fifteensuperior robusta coffee clones in Lampung Province. The fifteen clones consisted of four clones released by the Indonesian Coffee andCocoa Research Institute (ICCRI), i.e. ‘BP 409’,‘BP936’, ‘BP939’, ‘SA 237’, together with eleven superior coffee clones selected byfarmers from Tanggamus District (‘Tugino’, ‘Wanto’, ‘Biyadi’, ‘Komari’, ‘Wardi’, ‘Wariso’) and from West Lampung District (‘TuguKuning’, ‘Tugu Hijau', ‘Tugu Biru', ‘Tugu Sari', ‘Lengkong'). Fifteen qualitative and seven quantitative morphological characters wereevaluated in a randomized complete block design with three replicates for each clone,each replication consisted of two plants. Fromeach plant, four samples were taken from four sides of the plant (north, south, west, and east). It was found that while somemorphological characters exhibited negligible variation among clones, there were significant differences between clones for othercharacters. The characters that did not differ significantly between clones were: shapes of leaf base and leaf tip; petiole color; leafvenation pattern; fruit disk shape; ripe-fruit color; and stipule shape. The characters that varied between clones were shape of leaf lamina(elliptical vs. lanceolate); fruit shape (round vs. oval); and shape of leaf margins. Morphological variation was also observed in somequantitative characters: canopy diameter; tree height; stem diameter; leaf length; leaf width; petiole length; stipule length; and number ofprimary branches.

Arabidopsis thaliana homeodomain-leucine zipper type I transcription factors contribute to control leaf venation patterning

ABSTRACTVenation patterning is a taxonomic attribute for classification of plants and it also plays a role in the interaction of plants with the environment. Despite its importance, the molecular physiology controlling this aspect of plant development is still poorly understood. Auxin plays a central role modulating the final vein network and patterning. This addendum discusses recent findings on the role of homeodomain-leucine zipper (HD-Zip) transcription factors on the regulation of leaf venation patterning. Moreno-Piovano et al. reported that ectopic expression of a sunflower HD-Zip I gene, HaHB4, increased the asymmetry of leaf venation. Even more, this work showed that auxin transport in the leaf through LAX carriers controls venation patterning. Here, we provide evidence indicating that some Arabidopsis thaliana HD-Zip I genes play a role in the determination of the final leaf venation patterning. We propose that these genes contribute to regulate vein patterning, likely controlling auxin homeostasis.

Quantitative trait loci controlling leaf venation in Arabidopsis.

Leaf veins provide the mechanical support and are responsible for the transport of nutrients and water to the plant. High vein density is a prerequisite for plants to have C4 photosynthesis. We investigated the genetic variation and genetic architecture of leaf venation traits within the species Arabidopsis thaliana using natural variation. Leaf venation traits, including leaf vein density (LVD) were analysed in 66 worldwide accessions and 399 lines of the multi-parent advanced generation intercross population. It was shown that there is no correlation between LVD and photosynthesis parameters within A. thaliana. Association mapping was performed for LVD and identified 16 and 17 putative quantitative trait loci (QTLs) in the multi-parent advanced generation intercross and worldwide sets, respectively. There was no overlap between the identified QTLs suggesting that many genes can affect the traits. In addition, linkage mapping was performed using two biparental recombinant inbred line populations. Combining linkage and association mapping revealed seven candidate genes. For one of the candidate genes, RCI2c, we demonstrated its function in leaf venation patterning.

NET: a new framework for the vectorization and examination of network data

BackgroundThe analysis of complex networks both in general and in particular as pertaining to real biological systems has been the focus of intense scientific attention in the past and present. In this paper we introduce two tools that provide fast and efficient means for the processing and quantification of biological networks like Drosophila tracheoles or leaf venation patterns: the Network Extraction Tool (NET) to extract data and the Graph-edit-GUI (GeGUI) to visualize and modify networks.ResultsNET is especially designed for high-throughput semi-automated analysis of biological datasets containing digital images of networks. The framework starts with the segmentation of the image and then proceeds to vectorization using methodologies from optical character recognition. After a series of steps to clean and improve the quality of the extracted data the framework produces a graph in which the network is represented only by its nodes and neighborhood-relations. The final output contains information about the adjacency matrix of the graph, the width of the edges and the positions of the nodes in space. NET also provides tools for statistical analysis of the network properties, such as the number of nodes or total network length. Other, more complex metrics can be calculated by importing the vectorized network to specialized network analysis packages.GeGUI is designed to facilitate manual correction of non-planar networks as these may contain artifacts or spurious junctions due to branches crossing each other. It is tailored for but not limited to the processing of networks from microscopy images of Drosophila tracheoles.ConclusionThe networks extracted by NET closely approximate the network depicted in the original image. NET is fast, yields reproducible results and is able to capture the full geometry of the network, including curved branches. Additionally GeGUI allows easy handling and visualization of the networks.

Fabrication and testing of silicon-based microchannel heat exchanger inspired by leaf venation pattern for electronic cooling

Fabrication and testing of silicon-based microchannel heat exchanger inspired by leaf venation pattern for electronic cooling

Fabrication and testing of silicon-based microchannel heat exchanger inspired by leaf venation pattern for electronic cooling

Microchannel heat sinks (MCHS) provide an efficient means to dissipate large heat flux. The task of fabricating MCHS becomes challenging due to availability of large number of newer materials and processes. In this work, tetra methyl ammonium hydroxide (TMAH) etching and LASER machining methods for fabricating the microchannels are compared with respect to dimensional accuracy, the profile of channel, surface roughness, aspect ratio, material compatibility, cost and thermal performance. TMAH etching results in trapezoidal cavity instead of the rectangular cavity, finest surface finish (8 nm), and is suited for batch fabrication. While, LASER machining results in small taper profile (10o to vertical surface), rough surface (2.83 μm), and better dimensional accuracy and is suited for job production. Experimental results show that both MCHS exhibit similar thermal performance at lower flow rates. At higher flow rates, however, LASER fabricated MCHS have 25% higher thermal performance than TMAH etched channels.