Epidermal Micromorphology Research Articles

Foliar epidermal micro-morphology of selected brinjal varieties: A study on leaf surface characteristics

Studies on the leaf epidermal morphological characteristics were conducted on the three varieties of brinjal (Solanum melongena L.) belonging to the family Solanaceae. The varieties used in the study were Bhavani Gold, Purple Round and Haritha. Fresh mature brinjal leaves were randomly selected from the three experimental genotypes, and the foliar epidermal features were studied by using light microscopy and SEM imaging. Measurements were taken with an ocular and stage micrometer using 10X and 40X magnifications. The photographs were taken from mounted slides. The stomatal count and each measurement represent the average of ten readings. The upper and lower epidermal surfaces of leaf were studied for stomatal features including, stomatal distribution, stomatal type, stomatal index, stomatal pore length, stomatal pore width, guard cell length, guard cell width, subsidiary cell length and width, epidermal cell type, epidermal cell length and width, trichome type, trichome length and width. Amphistomatous, anisocytic, and with more stomata on the lower epidermal surface than the upper epidermal surface were present in all leaf varieties. On the leaves, the abaxial stomatal index ranged from 68.19 mm-2 (Bhavani Gold) to 56.67 mm-2 (Purple Round) to 58.8 mm-2 (Haritha). While on the adaxial surface, it varied from 59.67 mm-2 (Bhavani Gold), 53.46 mm-2 (Purple Round) and 56.67 mm-2 (Haritha). The three varieties of this study exhibited similarities in the pattern of epidermal cell on the adaxial and abaxial surfaces and were irregular in shape. Among the three varieties epidermal cell become irregular in outline and trichomes were present on both leaf surfaces. It becomes stellate, non-glandular, glandular and 8-12 in number. The highest trichome length was obtained in Bhavani Gold (63 μm) followed by Haritha (57.5 μm) and Purple Round (43 μm) on the upper epidermis. On the lower epidermal region maximum length was obtained in Bhavani Gold (65.5 μm) followed by Haritha (53 μm) and Purple Round (44 μm).

Lamiales epidermal dynamics: Unveiling antimicrobial resilience in a structural symphony.

This research on Lamiales epidermal anatomy not only provides in-depth understanding of their structural traits but also highlights the significance of uncovering the inherent antimicrobial resilience embedded within these plants. Such insights hold promise for advancing natural product-based approaches in medicine, potentially contributing to the development of novel antimicrobial agents inspired by Lamiales unique biological defense mechanisms. Scanning microscopic tools were utilized to conduct foliar epidermal anatomy of nine species that belong to seven genera and four families within the Lamiales order, Plantaginaceae, Scrophulariaceae, Verbenaceae, and Lamiaceae. This approach aimed to gather both qualitative and quantitative data, facilitating the assessment of taxonomic microanatomical significance. The shape of epidermal cells and their anticlinal walls; number of epidermal cells, stomata, and trichomes; type of stomata and trichomes; length and width of epidermal cells, trichomes, stomatal pore, guard cells, and subsidiary cells; and stomatal index were determined statistically. Most of the species examined were amphistomatous and showed extensive array of trichomes diversity. The exploration of Lamiales epidermal micromorphology and their antimicrobial potential were significant for their implications in multidisciplinary fields. The pharmacological research to utilize sustainable agricultural practices prompts avenues to strengths of Lamiales order for the development of novel antimicrobial solutions and ecological benefits. RESEARCH HIGHLIGHTS: Diverse trichome morphometry reveals a wide array of trichome structures across Lamiales species. Epidermal microscopic architecture variability of epidermal cell shapes and sizes signifies the interspecies variability. Secondary metabolite localization within microanatomical structures elucidates potential hotspots for antimicrobial compound production.

Chemotaxonomy compared to morphological and anatomical taxonomy of five Hibiscus species

Hibiscus is a charismatic genus of the Malvaceae family that is noted for its diversity, lacking identifiable characteristics for distinguishing its various species. Therefore, there is an urgent need to develop authentication methods for genus delimitation and species delineation. The present study aims to discern the taxonomic relationships between the well-known, globally familiar, and economically important five Hibiscus species, namely: H. × rosa-sinensis, H. sabdariffa, H. schizopetalus, H. syriacus and H. tiliaceus based on traditional morphological and anatomical characteristics compared to the contemporary chemotaxonomy. In this context, the leaf-based methanolic extracts of the studied species were analyzed by Gas Chromatography-Mass Spectrometer (GC–MS) to estimate their secondary metabolites similarity. In addition, selected qualitative morphological and anatomical traits including leaf venation patterns, epidermal micromorphology, stomata types and trichomes diversity, petiole serial sectioning (outline, adaxial groove features, vasculature traces arrangement), and midrib characteristics of the studied species were investigated. The results of both chemotaxonomy and traditional taxonomy exhibited a remarkable agreement in the delineation of the five studied species. Specifically, the chemotaxonomy-based dendrogram separates the studied species into two main clusters with the H. sabdariffa as an outlier species in a single cluster and the remaining four species as another cluster with variant distances in its similarity indices. Similarly, the traditional morphological and anatomical characteristics revealed distinct traits for H. sabdariffa compared to the remaining four species. The findings of this study highlight the significance of integrating the structural features with phytochemicals profiling as a potential approach that could be harnessed for the delineation of the taxonomically challenging Hibiscus genus.

Foliar epidermal micromorphology: a contribution to the taxonomy of family Oleaceae

Foliar epidermal micromorphology: a contribution to the taxonomy of family Oleaceae

Petal epidermal micromorphology of Korean Peucedanum L. species (Apiaceae) and its systematic significance

Peucedanum L. (Apiaceae) is broadly distributed in the Old World, and 11 taxa, including five endemic species, have been reported in Korea. In this study, we used scanning electron microscopy to describe petal epidermal cell patterns and evaluated their systematic implications for all Korean Peucedanum species except for one. This included two recently reported endemic species, P. miroense and P. tongkangense, which are closely associated with Heracleum moellendorffii. The epidermal characteristics of the petals, including cell type (papillose conical, papillose knobby rugose, tabular conical, or tabular rugose), anticlinal wall shape (straight, sinuous, or curved), cuticle sculpture (striate or wrinkled), and stomata (presence or absence) were observed. The petal epidermis could be categorized into three types and two subtypes. We concluded that petal epidermal characteristics provide evidence supporting the recent robust phylogeny that suggests the non-monophyly of the genus Peucedanum. In particular, P. japonicum and P. praeruptorum, which are positioned in different clades to the other species in the recent phylogeny, had different types of petal epidermis among the studied species. These petal epidermal micro-characteristics were evaluated as possible consistent parameters for the taxonomic delimitation of species of the genus Peucedanum.

Foliar epidermal micromorphology of genus Glochidion J.R.Forst. & G.Forst. (Phyllanthaceae) by using light and electron microscopy

The present study was conducted to compare both qualitative and quantitative characteristics of foliar epidermal micromorphology on some members of Glochidion in Assam. As taxonomic attributes, the foliar epidermal micromorphology study of nine taxa of both abaxial and adaxial surfaces was performed by using light microscopy (LM) and field emission scanning electron microscopy (FESEM). The result showed both amphistomatic and hypostomatic types of leaf surfaces. On the same surface of the leaf, multiple types of stomata were observed such as anomocytic, anisocytic, hemiparacytic, and paracytic types. Significant diversity and variations were observed in stomatal number, size, area, epidermal cell number, subsidiary cells, and trichomes. The stomatal index, stomatal shape, epidermal cell shape, length and width of the stomata, and trichomes showed variation among the studied taxa. Glands were absent in all studied members. Papillae and epicuticular wax crystals were observed in some taxa. In addition, a taxonomic key was also provided based on foliar leaf epidermal characteristics using qualitative and quantitative data from LM and FESEM. Based on quantitative data of foliar leaf micromorphology, principal component analysis (PCA) and cluster analysis were carried out to authenticate the micromorphological data. These would aid in the identification of taxa as well as in taxonomic delimitation.

Taxonomic implications of normal and abnormal stomatal complexes in Indigofera L. (Indigofereae, Faboideae, Fabaceae)

This study is the first to report the foliar and stem epidermal micro-morphology of 13 taxa of Indigofera L. (Fabaceae) using light (LM) and scanning electron microscopy (SEM). The micro-morphological characteristics studied here are related to the epidermal cell shape, size, frequency, anticlinal wall pattern, and stomatal complex types, size, position, frequency, and index. The study revealed 19 major normal stomatal types with eight subtypes and seven major abnormal stomatal types with 13 subtypes. The stomatal index was lower on the abaxial leaf surface than on the adaxial surface. Notably, the adaxial surface of I. hochstetteri had the highest stomatal index (27.46%), while the abaxial surface of I. oblongifolia had the lowest (9.95%). The adaxial surface of I. hochstetteri also displayed the highest average stomatal frequency (38.67), while the adaxial surface of I. spinosa had the lowest average frequency (9.37). SEM analysis revealed that most leaves had slightly sunken to sunken stomata, while stem stomata were positioned at the same level as epidermal cells in most taxa. Indigofera's foliar and stem epidermal anatomy recommends their application as baseline data coupled with other taxonomic data for the delimitation and differentiation of closely related taxa in the genus. The study provides a comprehensive description, illustrations, images, and micrographs of the stomatal types, as well as a taxonomic key for distinguishing the studied taxa of Indigofera.

Profiles of the Headspace Volatile Organic and Essential Oil Compounds from the Tunisian <i>Cardaria draba</i> (L.) Desv. and Its Leaf and Stem Epidermal Micromorphology

Profiles of the Headspace Volatile Organic and Essential Oil Compounds from the Tunisian <i>Cardaria draba</i> (L.) Desv. and Its Leaf and Stem Epidermal Micromorphology

Economically important species of Asteraceae: An overview of leaf epidermal micro-morphology with respect to water availability

This paper reports the result of a study undertaken with a view to documenting responses of leaf epidermal parameters of three economically important species of the family Asteraceae: Aspilia africana, Chromolaena odorata and Vernonia amygdalina from Nigeria to seasonal water stress. Obtained quantitative data showed a significant decrease (p < 0.05) in stomata density and index on the abaxial surface in Chromolaena odorata in dry conditions. The increased stomata densities and indices on the adaxial surfaces in Aspilia africana and Vernonia amygdalina in the wet season suggest that CO2 was more taken up. The reduction in stomata size (on both leaf surfaces in the three taxa) in the dry season indicated species' adaptations to dry conditions and reduction in stomatal conductance. Turgescent guard cell in the three species in the wet season indicated stomatal opening, which could, though, be a hormonal response to water availability since transpiration needed to be activated. The ability of Aspilia africana to reduce water loss and defend against herbivores greatly increased in plants that developed in dry conditions by possessing more multicellular trichomes in comparison to wet conditions, while in Vernonia amygdalina, the number increased during the wet season. Water stress had little or no effect on the micro-morphology of anticlinal walls and the shapes and arrangements of the epidermal cells in the three species. This study revealed that investigations into leaf epidermal micro-morphology might be a useful tool to elucidate the multiple mechanisms underlying leaf epidermal structure function in response to water availability.

The use of silicon and mycorrhizal fungi to mitigate changes in licorice leaf micromorphology, chlorophyll fluorescence, and rutin content under water-deficit conditions

In this study, the effects of water-deficit conditions, silicon (Si) fertilizer (300 ppm), and arbuscular mycorrhizal (AM) inoculation by Claroiedoglomus etunicatum were evaluated on several features of licorice (Glycyrrhiza glabra L.). The measurable features were photosynthetic parameters, rutin content in aerial parts, and leaf micromorphology. Drought was administered at five levels determined by the percentage of field capacity (FC), i.e. 100, 80, 60, 40, and 20% of FC. Leaf extracts were utilized for measuring rutin content (via HPLC), and photosynthetic pigments; measurement of stomatal density, and trichome analysis were performed by scanning electron microscopy (SEM). Under severe drought stress, leaf area decreased by 50.84%, compared to well-irrigated plants. A significant decrease in leaf numbers (32.52%) was observed because of deficit irrigation. AM and Si improved chlorophyll fluorescence, which corresponded to the maximum efficiency of photosystem II. Rutin content decreased significantly under deficit irrigation. Also, the integration of AM and Si treatments positively affected rutin quantity under various irrigation regimes. Under moderate stress (60% FC), using AM and/or Si treatments reduced the stomatal length by 61.22 and 52.98%, respectively. Interestingly, a significant reduction in stomatal density towards control was observed as a result of the integrated treatments of Si and AM (58.28% at W20 and 59.82% at W100), which helped plants reduce water loss when facing drought stress. Principal component analysis (PCA) showed that photosynthetic pigments, chlorophyll fluorescence, and rutin changed quantitatively under moderate drought stress, while more variations were observed in leaf epidermal micromorphology under severe drought stress. These findings revealed that Si and AM, by exogenous application, synergistically mitigated the effects of drought stress on licorice.

Micromorphology of epicuticular waxes in genus Mimosa (Fabaceae)

Epicuticular waxes crystallize on the foliar surface with different morphologies, which can be taxonomically relevant features in many taxa. Their morphological analysis was based on scanning electron microscopy (SEM) images on herbarium specimens of selected sections of Mimosa. The present work is the first detailed description and classification of the epidermal micromorphology in the genus Mimosa, focusing on section Calothamnos and Mimosa series Mimosa, subseries Dolentes and Brevipedes. We also describe different wax crystallization morphologies present in these taxa, identifying three different crystallization types: film, plates, and platelets. Novel epidermal micromorphologies have been described, such as papillae in M. lepidorepens. Results allow grouping taxa of the studied sections, contributing to clarifying their taxonomy. SEM images of epicuticular waxes and leaf surfaces could be a new tool for performing a new taxonomic treatment of section Mimosa subser. Dolentes and subser. Brevipedes, and section Calothamnos.

The diversity of elaborate petals in Isopyreae (Ranunculaceae): a special focus on nectary structure.

Elaborate petals are highly diverse in morphology, structure, and epidermal differentiation and play a key role in attracting pollinators. There have been few studies on the elaborate structure of petals in the tribe Isopyreae (Ranunculaceae). Seven genera in Isopyreae (Aquilegia, Semiaquilegia, Urophysa, Isopyrum, Paraquilegia, Dichocarpum, and Leptopyrum) have petals that vary in morphology, and two genera (Enemion and Thalictrum) have no petals. The petals of nine species belonged to 7 genera in the tribe were studied to reveal their nectary structure, epidermal micromorphology and ancestral traits. The petal nectaries of Isopyreae examined in this study were located at the tip of spurs (Aquilegia yabeana and A. rockii), or the bottom of shallow sacs (Semiaquilegia adoxoides, Urophysa henryi, Isopyrum manshuricum, and Paraquilegia microphylla), a cup-shaped structure (Dichocarpum fargesii) and a bilabiate structure (Leptopyrum fumarioides). The petal nectary of eight species in Isopyreae (except A. ecalcarata) was composed of secretory epidermis, nectary parenchyma, and vascular tissues, and some sieve tubes reached the secretory parenchyma cells. Among the eight species with nectaries examined in the present study, A. yabeana had the most developed nectaries, with 10-15 layers of secretory parenchyma cells. The epidermal cells of mature petals of the nine species were divided into 11 types. Among these 11 types, there were two types of secretory cells and two types of trichomes. Aquilegia yabeana and A. rockii had the highest number of cell types (eight types), and I. manshuricum and L. fumarioides had the lowest number of cell types (three types). Aquilegia ecalcarata had no secretory cells, and the papillose conical polygonal secretory cells of D. fargesii were different from those of the other seven species with nectaries. Trichomes were found only in Aquilegia, Semiaquilegia, Urophysa, and Paraquilegia. The ancestral mode of nectar presentation in Isopyreae was petals with hidden nectar (70.58%). The different modes of nectar presentation in petals may reflect adaptations to different pollinators in Isopyreae.

Pharmacognostic and Phytochemical Evaluation of Leaf of Jatropha nana var. bengalense C.H. Rahaman and S. Mondal: An Endemic Member of Euphorbiaceae

Pharmacognosy Research,2022,14,2,204-210.DOI:10.5530/pres.14.2.29Published:April 2022Type:Original ArticleAuthors:Swarnendu Mondal, and Nayan Roy Author(s) affiliations:Swarnendu Mondal1,*, Nayan Roy2 1Department of Botany, Tribal Medicine and Pharmacognosy Lab., MUC Women’s College, Burdwan, West Bengal, INDIA. 2Department of Zoology, Ecology Research Unit, MUC Women’s College, Burdwan, West Bengal, INDIA. Abstract:Background: Pharmacognostic and phytochemical studies helps to maintain the quality of herbal products and purity of crude drugs by means of standardized parameters which will lead to developing the safest and efficacious natural products. Objectives: This study was undertaken to carry out pharmacognostic and phytochemical investigation of the leaves of the Jatropha nana var. bengalense (Euphorbiaceae), an ethnomedicinal plant. Materials and Methods: Epidermal Micromorphology, physical and physicochemical constants like ash value determination and UV-fluorescence study have been employed for pharmacognostic evaluation. For qualitative phytochemistry, microchemical color reaction test and TLC studies performed. Variations in different biochemical parameters of leaves of different developmental stages have been examined and the obtained data statistically analyzed following standard methods. Results: Typical paracytic type of stomata is found in hypostomatic condition distributed in irregular-shaped epidermal cells. Index of these stomata was found 20.251%. Phytochemical analysis in qualitative and quantitative approaches has also been done to describe its chemical variability. Ash value was found above 8% which shows more than 50% solubility in acid whereas water and ethanol solubility is found to be just below and above the 30% respectively. In UV- fluorescence study very distinctive colour changes of the powdered leaf have been recorded. Alcoholic extracts have shown positive results for presence of most of the phytochemical groups. Quantitative phytochemical analysis confirms that a range of phytochemicals are present in good amount in the leaves of this medicinal plant which could vary in amount in different developmental states. Thin Layer Chromatography has been carried out on ethanolic extract in two different solvent systems which show 6 different Rf values further indicates the presence of important phytochemical derivatives. Conclusion: This study will finally be needful for standardization of identification of the genuine drug, its adulterants and of the chemical constituents present in the leaves and finally bioprospection. Key words: Adulteration, Bioprospection, Euphorbiaceae, Jatropha nana var. bengalense, Pharmacognosy. View:PDF (450.58 KB)

Implications of foliar epidermal micromorphology using light and scanning electron microscopy: A useful tool in taxonomy of Korean irises

The genus Iris L., comprising approximately 210 species, is one of the most species-rich genera in the family Iridaceae. In this study, the first comprehensive leaf micromorphological characters of Korean irises were studied using light and scanning electron microscopy. Our objective was to evaluate the foliar micromorphological characteristics (namely epidermal cells, stomata types, and guard cell size) of Korean Iris taxa in a systematic context. All the investigated Korean Iris taxa had amphistomatic or hypostomatic leaves with anomocytic stomatal complexes. Guard cell length varied among species, ranging from 24.8μm (I. rossii) to 56.0μm (I. domestica). Although the presence of papillae on the outer periclinal wall is not of taxonomic significance, leaf margin pattern, guard cell size, and sunken stomata type were useful for species-level identification of Korean Iris species. The occurrence of polymorphic stomatal types was reported here for the first time, and the correlation between genome size and epidermal guard cell length was discussed.

Leaf epidermal micromorphology of Zingiber (Zingiberaceae) from China and its systematic significance.

Leaf epidermal characteristics are important for phylogenetic and taxonomic studies of many plants, but there is currently insufficient such data for this application in Zingiber species. Therefore, the leaf epidermal micromorphology of 22 species in three sections of Zingiber was investigated by light microscopy and scanning electron microscopy. Differences between various taxonomic groups of Zingiberaceae were also compared to assess their phylogenetic and taxonomic significance. As in other genera of Zingiberaceae, the epidermal cells in both the adaxial and abaxial epidermis of Zingiber species were found to be hexagonal or polygonal, with non-sinuous anticlinal walls that are arranged parallel to leaf veins. Tetracytic stomata are mostly randomly distributed in the intercostal regions of both surfaces and are more common on the abaxial surface. The stomatal density of the species in sect. Pleuranthesis is significantly lower than that in sects. Zingiber and Cryptanthium. There are two types of trichome in Zingiber: so-called “delicate” trichomes are present in most species, while “stout” trichomes with a swollen base are only found in Z.corallinum and Z.montanum. Oil cells occur in both epidermal layers of some species in sects. Zingiber and Cryptanthium, but only in the abaxial epidermis of Z.ellipticum in sect. Pleuranthesis. Crystals are found in the abaxial epidermis only in all species, but are present in both epidermal layers of Z.corallinum and Z.montanum. Although the epidermal morphology is similar in most Zingiber species, stomatal density, type of trichome and distribution of oil cells and crystals offer valuable information for the systematic and taxonomic studies in this genus.

Two centuries from species discovery to diagnostic characters: molecular and morphological evidence for narrower species limits in the widespread SW Australian Anarthria gracilis complex (Restionaceae s.l./Anarthriaceae, Poales).

BackgroundThe extreme southwest of Australia is a biodiversity hotspot region that has a Mediterranean-type climate and numerous endemic plant and animal species, many of which remain to be properly delimited. We refine species limits in Anarthria, a Western Australian endemic genus characterised by the occurrence of the greatest number of plesiomorphic character states in the restiid clade of Poales. In contrast to many other groups of wind-pollinated Australian Poales, Anarthria was traditionally viewed as having well-established species limits. All six currently recognised species, which are conspicuous members of some Western Australian plant communities, were described in the first half of the 19th century. They are traditionally distinguished from each other mainly using quantitative characters.MethodsWe examined extensive existing herbarium specimens and made new collections of Anarthria in nature. Scanning electron microscopy and light microscopy were used to study leaf micromorphology. Molecular diversity of Anarthria was examined using a plastid (trnL-F) and a low-copy nuclear marker (at103). This is the first study of species-level molecular diversity in the restiid clade using a nuclear marker.ResultsMaterial historically classified as Anarthria gracilis R.Br. actually belongs to three distinct species, A. gracilis s.str., A. grandiflora Nees and A. dioica (Steud.) C.I.Fomichev, each of which forms a well-supported clade in phylogenetic analyses. Both segregate species were described in the first half of the 19th century but not recognised as such in subsequent taxonomic accounts. Anarthria dioica was first collected in 1826, then wrongly interpreted as a species of Juncus (Juncaceae) and described as Juncus dioicus. We provide a formal transfer of the name to Anarthria and for the first time report its clear and qualitative diagnostic characters: an extremely short leaf ligule and distinctive pattern of leaf epidermal micromorphology. A long ligule is present in A. gracilis s.str. and A. grandiflora. These species differ from each other in leaf lamina morphology and anatomy and have mostly non-overlapping distribution ranges. The narrower definition of species provides a basis for future phylogeographic analyses in Anarthria. Our study highlights a need for more extensive use of nuclear DNA markers in Restionaceae. The use of the low copy nuclear marker at103 allowed a clade comprising all three ligulate species of Anarthria to be recognised. The ligule character is used here for the first time in the taxonomy of Anarthria and merits special attention in studies of other restiids. In general, our study uncovered a superficially hidden but, in reality, conspicuous diversity in a common group of wind-pollinated plants in the southwest of Western Australia.

Taxonomic implications of leaf epidermis in halophytes of Amaranthaceae from Salt Range of Punjab, Pakistan

The leaf epidermal anatomy of 15 salt-tolerant plant species belonging to the Amaranthaceae from the Salt Range of Punjab-Pakistan was studied using light microscopy (LM). The main purpose of this investigation was to compare the leaf micro-morphologies of the studied taxa, which can provide diagnostic characters useful for correct identification of halophytic taxa. Various quantitative and qualitative foliar epidermal features of adaxial and abaxial surfaces, including epidermal cell shape, anticlinal wall pattern, lobes per cell, anomocytic, anisocytic, and paracytic types of stomata and trichome diversity, were studied. Eight types of trichomes reported for the halophytes studied i.e. stellate, glandular, conical, capitate, non-capitate, non-glandular, cylindrical, and falcate. The shapes of epidermal cells found are pentagonal, polygonal, irregular, wavy, and tetragonal. This is the first report on leaf epidermal micromorphology of halophytes of family Amaranthaceae of Salt Range of Punjab. The findings revealed that leaf epidermal features showed adequate variations among genera distinguishing the halophytic taxa of family Amaranthaceae.

Leaflet blade epidermis and its taxonomic significance in 13 species of Bignonieae (Bignoniaceae) from Pico do Jabre, Paraíba, northeast of Brazil

Bignonieae is the largest tribe of Bignoniaceae, with 21 genera and 393 species of lianas and shrubs that are 1–3-foliolate with the terminal leaflet modified as tendrils. We examined the micromorphologies of the epidermis from the leaflet blade of 13 species of Bignonieae belonging to Amphilophium, Anemopaegma, Bignonia, Cuspidaria, Dolichandra, Fridericia, Pyrostegia, Tanaecium, and Xylophragma, from Pico do Jabre, Paraíba, Brazil. These are lianas except for Tanaecium parviflorum (shrub). We sought to identify the epidermal leaflet parameters to support their taxonomy, subject to great similarities between their vegetative characters, mainly in species of the same genus and related genera. Analyses were performed using light and scanning electron microscopy, and showed five types of epicuticular waxes, four cuticle types, three epidermal cell anticlinal wall types, and nonglandular and glandular trichomes. Hypostomatic leaves showed 10 different types of stomata, with stomatal indices from 6.21% (Bignonia ramentacea) to 23.52% (Tanaecium parviflorum), and stomatal densities from 76 stomata/mm2 (Pyrostegia venusta) to 752.9 stomata/mm2 (T. parviflorum). The presence of raphides in Amphilophium crucigerum and styloids in Fridericia pubescens constitute the first records for these genera. Epidermal micromorphology provided a set of distinctive characters with which to separate these species, representing an additional tool to support their taxonomies, as well as that of tribe Bignonieae.

Role of epidermal micromorphology in delimitation of taxa in genus Andrographis (Acanthaceae) in India

Role of epidermal micromorphology in delimitation of taxa in genus Andrographis (Acanthaceae) in India

Soil and foliar application of rock dust as natural control agent for two-spotted spider mites on tomato plants

Mineral-based products represent a valid alternative to synthetic pesticides in integrated pest management. We investigated the effects of a novel granite dust product as an agent for controlling two-spotted spider mites, Tetranychus urticae Koch (Acari: Tetranychidae), on tomato plants (Solanum lycopersicum L.). Two-choice tests for repellency and repulsiveness, and no-choice bioassays with different type of applications (soil, foliar, and soil–foliar) were used in order to evaluate performance and action of the product. Evaluation of epidermal micromorphology and mesophyll structure of treated plants and elemental analyses of leaves were performed. In repulsiveness experiments, almost all dust treatments significantly inhibited mites from migrating to and/or settling on the treated leaf. In repellency experiments, foliar and soil dust treatments were not significantly different from control. Significant mortality was observed for all dust treatments in two-choice and in no-choice bioassays, suggesting mites are susceptible to rock dust by contact, and by indirect interaction through the feeding on plants subjected to soil application of rock dust. Leaf epidermal micromorphology and mesophyll structure of treated plants showed structural variation due to mineral accumulation, which was also confirmed by elemental analyses of leaves. These results demonstrate for the first time that granite rock dust interacts with two-spotted spider mites by modifying pest behavior and via acaricidal action, providing more insights in understanding the mechanism of this novel natural product as pest management tool.