The Promise of Molecular and Genomic Techniques for Biodiversity Research and DNA Barcoding of the Arabian Peninsula Flora

The Arabian Peninsula is known to have a comprehensive and rich endowment of unique and genetically diverse plant genetic resources. Analysis and conservation of biological diversity is a crucial issue to the whole Arabian Peninsula. The rapid and accurate delimitation and identification of a species is crucial to genetic diversity analysis and the first critical step in the assessment of distribution, population abundance and threats related to a particular target species. During the last two decades, classical strategies of evaluating genetic variability, such as morphology and physiology, have been greatly complemented by phylogenetic, taxonomic, genetic diversity and breeding research molecular studies. At present, initiatives are taking place around the world to generate DNA barcode libraries for vascular plant flora and to make these data available in order to better understand, conserve and utilize biodiversity. The number of herbarium collection-based plant evolutionary genetics and genomics studies being conducted has been increasing worldwide. The herbaria provide a rich resource of already preserved and identified material, and these as well as freshly collected samples from the wild can be used for creating a reference DNA barcode library for the vascular plant flora of a region. This review discusses the main molecular and genomic techniques used in plant identification and biodiversity analysis. Hence, we highlight studies emphasizing various molecular techniques undertaken during the last 10 years to study the plant biodiversity of the Arabian Peninsula. Special emphasis on the role of DNA barcoding as a powerful tool for plant biodiversity analysis is provided, along with the crucial role of herbaria in creating a DNA barcode library

Genetic distance.

<p>Distribution of intra and inter specific K2P mean divergence (arranged in ascending order). (a) ITS2 and ITS2+<i>matK</i> (concatenated) are represented by grey and black colors respectively. (b) For <i>atpF-atpH</i>, <i>psbK-psbI and rpoC1</i> markers maximum intraspecific distance and minimum interspecific distance to nearest neighbor are represented by a bar.</p

Fuzzy nanofibrous network of polyaniline electrode for supercapacitor application

Fuzzy nanofibrous network of polyaniline electrode is successfully electrosynthesized for supercapacitor application. The nanofibre network of polyaniline electrode is characterized using Fourier transforms infrared spectroscopy (FTIR), scanning electron microscope (SEM) and optical absorption studies. Network of polyaniline is highly porous with interconnected fuzzy nanofibres having diameter typically between 120 and 125 nm. The supercapacitive performance of polyaniline electrode is tested using cyclic voltammetry (C-V) technique in H2SO4 electrolyte within potential range of -100 to 800 mV. The effect of scan rate on the capacitance of polyaniline electrode is studied. The highest specific capacitance of 839 F g-1 at the voltage scan rate of 10 mV s-1 is achieved. Additionally stability and charging-discharging of polyaniline electrode are studied

Fabrication of copper oxide multilayer nanosheets for supercapacitor application

Copper oxide multilayer nanosheets thin films have been formed using simple and inexpensive chemical bath deposition (CBD) method. These films were characterized using X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Fourier transform infrared spectrum (FTIR), optical absorption and wettability test. The XRD pattern revealed that the copper oxide films are amorphous. Formation of copper oxide compound was confirmed from the FTIR studies. The FESEM images revealed the development of hierarchical multilayer nanosheets which covered the substrate surface. Surface wettability with liquid interface showed hydrophilic nature with water contact angle 53°. The optical absorption showed existence of direct optical band gap of energy 2.18 eV. The supercapacitive properties of copper oxide thin film investigated in 1 M Na2SO4 electrolyte showed supercapacitance of 43 F g-1 at scan rate 10 mV s-1

Hydrophilic polyaniline nanofibrous architecture using electrosynthesis method for supercapacitor application

An electrosynthesis process of hydrophilic polyaniline nanofiber electrode for electrochemical supercapacitor is described. The TGA-DTA study showed polyaniline thermally stable up to 323 K. Polyaniline nanofibers exhibit amorphous nature as confirmed from XRD study. Smooth interconnected fibers having diameter between 120-125 nm and length typically ranges between 400-500 nm observed from SEM and TEM analysis. Contact angle measurement indicated hydrophilic nature of polyaniline fibers. Optical study revealed the presence of direct band gap with energy 2.52 eV. The Hall effect measurement showed room temperature resistivity ∼3 × 10-4 Ω cm and Hall mobility 549.35 cm-2V-1 s-1 . The supercapacitive performance of nanofibrous polyaniline film tested in 1 M H2SO4 electrolyte and showed highest specific capacitance of 861 F g-1 at the voltage scan rate of 10 mV/s

Automated partition.

<p>The automatic partition by ABGD with three metrics (JC69, K2P and p-distance) and two X-values (X = 1, 1.5) for (a) ITS2 (initial partition 1,2 and Recursive partition 3 and 4); (b) <i>matK</i> (initial partition 1,2 and Recursive partition 3 and 4); (c) ITS2+<i>matK</i> (initial partition 1,2 and Recursive partition 3 and 4);(d) <i>atpF-atpH</i> and <i>psbK-psbI</i> (initial partition 1,2 for <i>atpF-atpH</i> and Initial partition 3 and 4 for <i>psbK-psbI</i>).</p

Evaluation of multilocus marker efficacy for delineating mangrove species of West Coast India

<div><p>The plant DNA barcoding is a complex and requires more than one marker(s) as compared to animal barcoding. Mangroves are diverse estuarine ecosystem prevalent in the tropical and subtropical zone, but anthropogenic activity turned them into the vulnerable ecosystem. There is a need to build a molecular reference library of mangrove plant species based on molecular barcode marker along with morphological characteristics. In this study, we tested the core plant barcode (<i>rbcL</i> and <i>matK</i>) and four promising complementary barcodes (ITS2, <i>psbK-psbI</i>, <i>rpoC1</i> and <i>atpF-atpH</i>) in 14 mangroves species belonging to 5 families from West Coast India. Data analysis was performed based on barcode gap analysis, intra- and inter-specific genetic distance, Automated Barcode Gap Discovery (ABGD), TaxonDNA (BM, BCM), Poisson Tree Processes (PTP) and General Mixed Yule-coalescent (GMYC). <i>matK</i>+ITS2 marker based on GMYC method resolved 57.14% of mangroves species and TaxonDNA, ABGD, and PTP discriminated 42.85% of mangrove species. With a single locus analysis, ITS2 exhibited the higher discriminatory power (87.82%) and combinations of <i>matK</i> + ITS2 provided the highest discrimination success (89.74%) rate except for <i>Avicennia</i> genus. Further, we explored 3 additional markers (<i>psbK</i>-<i>psbI</i>, <i>rpoC1</i>, and <i>atpF</i>-<i>atpH</i>) for <i>Avicennia</i> genera (<i>A</i>. <i>alba</i>, <i>A</i>. <i>officinalis</i> and <i>A</i>. <i>marina</i>) and <i>atpF-atpH</i> locus was able to discriminate three species of <i>Avicennia</i> genera. Our analysis underscored the efficacy of <i>matK</i> + ITS2 markers along with <i>atpF-atpH</i> as the best combination for mangrove identification in West Coast India regions.</p></div

Distance summary.

<p>Distance summary.</p

TaxonDNA analysis.

<p>TaxonDNA analysis.</p

Bayesian phylogenetic tree.

<p>Bayesian phylogenetic tree of (a) ITS2 and (b) <i>matK</i>+ITS2 gene. Vertical boxes on the right indicate the clades detected by the coalescent-based GMYC, PTP, the distance-based ABGD and TaxonDNA methods.</p