Endemic species analysis: Foliar epidermal anatomical characters of Aster glehnii F. Schmidt (Asteraceae)

The classification and identification of Aster glehnii F. Schmidt are determined from its foliar epidermal anatomical features. Scanning electronic microscopy has been used to determine the foliar epidermal anatomical characteristics of the species in detail. This study compared the qualitative and quantitative characteristics of the leaf epidermis of A. glehnii for taxonomic identification to be used as a reference for future studies on the species. A. glehnii has smooth, thin cuticles, depressed anomocytic stomata dispersed randomly throughout the leaf surface, polygonal epidermal cells with straight to slightly curved anticlinal walls, and no trichomes. There are obvious veins containing thick‐walled bundle sheath cells. The stomatal density is between 100 and 150 stomata per millimeter. The vein density ranges from five to 10 veins per millimeter, and the epidermal cells are 10 to 20 μm long and 5 to 10 μm in width. Understanding the connections between the different A. glehnii species and categorizing and identifying them depend heavily on these foliar epidermal structural features. Taxonomy and conservation are closely intertwined because the former serves as the basis for comprehending and safeguarding biodiversity.


| INTRODUCTION
A. glehnii is a perennial plant in the family Asteraceae that is widespread in Ulleungdo Island, South Korea, and Sakhalin, Japan (Hokkaido, Honshu).The whole plant body extract has been used historically in Asian traditional medicine for its anti-inflammatory properties, and it has been included in cosmetic formulas more recently (Kim et al., 2010;Tao et al., 2010).Young A. glehnii leaves and stems harvested from the wild have long been used as vegetables in Korea (Hong & Gruda, 2020).Numerous A. glehnii plants exhibiting powdery mildew signs were discovered in a public garden in Daegu City, Korea, in October 2015 (35 48 0 06.5 00 N; 128 31 0 14.2 00 E) (Cho et al., 2016).
For example, the leaves are shaped differently and are covered with a dense coating of glandular, waxy trichomes (Uzelac et al., 2021).
Numerous studies have used microscopy to examine the foliar epidermal anatomical characteristics of several plant species, including A. glehnii F. Schmidt.These investigations have yielded important understandings of how plants adapt structurally and morphologically to their particular surroundings.For example, the foliar epidermal architecture of three species of Asters was examined using microscopy to evaluate drought tolerance (Karanovi c et al., 2015).The size, shape, and density of epidermal cells varied significantly across species.A. glehnii has smaller and more densely packed epidermal cells than the other two species, indicating its adaptability to drier environments (Schweingruber, 2012).This research also discovered trichomes on the surface of A. glehnii leaves, which reduce water loss via transpiration.
Using microscopy, researchers examined the foliar epidermal structure of A. glehnii populations from marshes, grasslands, and woods (Munir, Khan, et al., 2011).The size and form of epidermal cells differed significantly among the groups, which may be attributed to their adaptability to various environmental factors (Poorter et al., 2009).Epidermal cells in wetlands were larger and more asymmetrical in form, while those in forests were smaller and more regular.
These differences were attributed to varying light intensities and water availability in the various environments.
The limited range and possible hazards to the habitat of A. glehnii F. Schmidt raise questions about its conservation status (Mace, 2004).
The Primorsky Krai region in the Russian Far East, South Korea, and Japan is home to the tiny native range of this species.Rocky slopes, woodland borders, and coastal meadows are some of its native habitats.The surviving populations of A. glehnii are seriously threatened by human activities, including deforestation, urbanization, and agricultural growth (Matsushita et al., 2023).There is a loss and fragmentation of natural habitats as a consequence of their conversion for agriculture and development.Furthermore, gathering plants for gardening might be a factor in decreasing the natural populations.Conservation initiatives are being carried out to preserve A. glehnii and its environment (Nakahama et al., 2022).The species is protected legally, and its harvest from the wild is forbidden because of its listing as "Vulnerable" in the Russian Federation's Red Data Book (Samy-Kamal et al., 2023).In addition, several protected areas, such as the Ussuriysky Nature Reserve and the Lazovsky State Nature Reserve, have been designated within its distribution zone.The natural habitats of A. glehnii and other endangered species will be preserved in these protected areas (Ozaki et al., 2006).For conservation strategies, further study is required to comprehend the ecological needs, population dynamics, and any dangers that A. glehnii faces (Shirane et al., 2021).This knowledge will be essential for developing conservation plans that work and guarantee the long-term survival of this rare and endangered species.The overall conservation status of Aster glehnii is concerning because of habitat loss, fragmentation, and possible over-collection.Hence, conservation measures, such as study, habitat preservation, and legal protection, are crucial for maintaining this uncommon species and its distinctive genetic diversity.
This study thoroughly examined the foliar epidermal anatomical features of A. glehnii.The leaf surface characteristics and epidermal architecture were investigated using optical and scanning electron microscopy (SEM).The findings provide insight into the evolutionary background of this endemic species.Furthermore, the significance of conservation efforts to save this and other endemic species in South Korea's distinct and varied habitats is underscored by these results.

| Gathering and producing ready plant samples
Plant samples of A. glehnii were collected from the natural habitats of each species from South Korea, and the foliar epidermal anatomical features were analyzed (Shiba et al., 2022).The collection sites were chosen carefully to accurately depict the geographical area of the species (Zhou et al., 2019).A range of mature, healthy leaves were selected from individuals to allow for intraspecific variance (Breza, 2023).A mild detergent solution was used to clean the leaves and remove any surface impurities (Allafi et al., 2022).The leaves were cleaned with distilled water and then gently blotted dry with absorbent paper (Long et al., 2023).During the preparation phase, great care was taken to maintain the integrity of the leaf surface (Codner et al., 2021).

| Techniques for SEM
SEM was used to examine the foliar epidermal characteristics of A. glehnii (de Silveira et al., 2020).SEM permits detailed examinations of epidermal cells, stomata, trichomes, and other microstructures (Bahadur et al., 2020).Small leaf portions were removed to prepare the samples for SEM.Subsequently, these pieces were adhered to SEM stubs using double-sided adhesive tape or conductive glue (Yuan et al., 2023).The samples were then sputter-coated with a thin coating of conductive material, such as gold or gold/palladium (Ul-Hamid, 2018), to prevent surface charging (Ayaz et al., 2020).Imaging was done at the appropriate accelerating voltage and working distance after loading the prepared samples into the SEM chamber (Ayaz & Yanartas ¸, 2020).Many sections of each leaf sample were examined to gain an accurate depiction of the foliar epidermal characteristics.Several SEM magnifications were used to capture the macroscopic and microscopic features (Jan et al., 2020).

| Techniques for gathering and analyzing data
The SEM images were used for data processing and quantifying the foliar epidermal anatomical features (Rajput et al., 2021).Measurements and observations were conducted using advanced image analysis tools (Imagj) (Willick et al., 2018).The stomatal density, trichome presence, epidermal cell arrangement and structure, and other significant features were examined (Alonso-Forn et al., 2023).The image analysis program, ImageJ, was used to measure the size of the cells, the stomata, and the features of the trichomes using the calibrated scales or measuring equipment (Munir, Wong, & Xagoraraki, 2011;Ullah et al., 2022).
The species was identified and categorized by analyzing the collected data using reference specimens, taxonomic keys, and previous reports (Schoch et al., 2020).The foliar epidermal properties of A. glehnii were described and compared by data analysis, which also provided information on their taxonomic connections and phylogenetic implications (Estrada-Peña et al., 2018).The foliar epidermal anatomical properties of A. glehnii were evaluated using collected and processed plant samples to gain a further understanding of the taxonomy and phylogeny of these plants (Francis et al., 2010;Horton et al., 2021).

| Taxonomic and conservation integration
The combination of taxonomy and conservation is a key strategy for biodiversity conservation that works.It talks about how taxonomic research, such as phylogenetic and revisionary taxonomic studies, may provide important information for determining the risks to a species, evaluating its conservation status, and developing focused conservation plans (Sandall et al., 2023).Taxonomic and conservation data needs to be incorporated into spatial analysis to find "biodiversity hotspots," or regions with high levels of biodiversity and endemism (Shipley & McGuire, 2022).Lastly, it offers concrete instances of how combining taxonomy and conservation has improved the preservation of ecosystems and vulnerable species (Wallace, 2007).This is important because it emphasizes how crucial it is for taxonomists and conservationists to work together to overcome the global biodiversity issue.Taxonomists and conservationists can identify and save the earth's most endangered, endemic, and rare species and habitats, ensuring that the amazing biodiversity of this planet survives for a long time.

| RESULTS
The taxonomy and identification of A. glehnii depend on its foliar epidermal anatomical characteristics.The qualitative and quantitative properties of the leaf epidermis can be used to differentiate A. glehnii from other species in the genus Aster (Figure 1).

| Epidermal cells
The anticlinal walls of epidermal cells and their form may have important taxonomic implications.The epidermal cells of A. glehnii have a polygonal form and anticlinal walls that are straight to slightly curved.This is not the case for certain other species in the Aster genus, which have more strongly wavy anticlinal walls or rounded epidermal cells.

| Cuticle
Taxonomically, the cuticle thickness and smoothness may also be significant.The cuticle of A. glehnii is smooth and thin.By contrast, the cuticles of several other species in the genus Aster are thicker or wrinklier.

| Stomata
The stomata type, density, and distribution may be important.The stomata of A. glehnii are depressed, anomocytic, and dispersed randomly throughout the leaf surface.By contrast, other species of the genus Aster have distinct forms of stomata, such as anisocytic or paracytic stomata, or have stomata that are not sunken or scattered in a different pattern.

| Trichomes
The presence or absence of trichomes can have taxonomically important differences.Trichomes are not present in A. glehnii.In contrast, trichomes of different kinds are observed in certain other species within the genus Aster.

| Veins
The bundle sheath cell thickness and vein prominence may have important taxonomic implications.The veins of A. glehnii are noticeable and include bundle sheath cells with thick walls.This contrasts with several other species of the genus Aster, which have thinnerwalled bundle sheath cells or less pronounced veins.

| Size of epidermal cells
The size of epidermal cells might be important.The epidermal cells of A. glehnii are 10 to 20 μm in length and 5 to 10 μm in breadth.This contrasts with the larger or smaller epidermal cells observed in certain other species in the genus Aster.

| Density of the stomata
In terms of taxonomy, the stomata density may matter.The stomatal density of A. glehnii is between 100 and 150 stomata per millimeter.
In comparison, the stomatal density of several other species in the genus Aster is higher or lower.

| Density of vein
Vein density of A. glehnii varies from 5 to 10 veins per millimeter.In comparison, the vein density of several other species in the genus Aster is greater or lower.The foliar epidermal anatomical characteristics are crucial for classifying and identifying A. glehnii.These traits may be utilized to identify A. glehnii from other species in the Aster genus and comprehend the connections among various species.

| Taxonomy and conservation: A case study of Aster glehnii
The conservation of A. glehnii, a rare plant species native to the Russian Far East, South Korea, and Japan, underscores how crucial it is for taxonomy and conservation to work together.Understanding the range and genetic diversity of a species and its preferred habitats and niches is critical for developing successful conservation plans using taxonomic and conservationist research.Low genetic diversity within populations and considerable genetic divergence across A. glehnii populations would be necessary for species conservation.initiatives.To safeguard and maintain this endangered plant species, conservationists may make well-informed judgments and carry out focused activities by being thoroughly aware of the taxonomic status, genetic diversity, and preferred habitats of the species.

| DISCUSSION
The study findings provide perspectives on the foliar epidermal structural traits of A. glehnii (Bakalin et al., 2022).The qualitative and quantitative features of the leaf epidermis matched those described for other species within the genus Aster (Fenollosa & Munné-Bosch, 2018).On the other hand, some distinctions were also observed, such as the sunken stomata in A. glehnii, which is not a characteristic shared by other Aster species.A. glehnii may have sunken stomata due to environmental adaptation (Royer et al., 2013).
Reduced water loss via transpiration benefits plants that thrive under dry conditions, and sunken stomata may help this.Furthermore, sunken stomata may help shield the stomata from harm brought on by wind or other external elements (Otis Prud'homme, 2018).
The study findings also shed light on the taxonomic connections between A. glehnii; the results are similar to the published study (Khan et al., 2023).The leaf epidermis qualitative and quantitative properties were comparable to those of other species in the section Aster, such as A. novae-angliae and A. novi-belgii (Moyo et al., 2022).This suggests that these species and A. glehnii are closely related.The study findings also highlight certain distinctions between A. glehnii and other Aster species.Compared to other Aster species, A. glehnii has a larger stomatal density (Moyo et al., 2022).This discrepancy might be because A. glehnii is indigenous to Japan, a country with a more humid environment than other places where Aster species are found (Nobela, 2018).
These findings align with earlier research on the foliar epidermal structure of Aster species (Ambrosone et al., 2023).Nevertheless, this research offers fresh perspectives on the qualitative and quantitative traits of the leaf epidermis of A. glehnii (Messina, 2013).These discoveries advance the knowledge of the taxonomy and evolutionary history of the genus Aster (Prado, 2023).
The identification of A. glehnii may be affected by the study findings (Jyske et al., 2016).The qualitative and quantitative properties of the leaf epidermis may be used to differentiate A. glehnii from other Aster species (Esteban et al., 2023).Botanists and other plant scientists attempting to identify and categorize Aster species may find this material beneficial (Health et al., 2023).In addition to the taxonomic consequences, the findings of this investigation might also have ecological ramifications. A. glehnii has sunken stomata due to environmental adaptation (Esteban et al., 2023).Hence, A. glehnii is more tolerant to arid environments than other Aster species (Esteban et al., 2023).Land managers and conservationists trying to manage and conserve Aster species may find this information helpful (Bashir et al., 2020).
These results highlight how crucial it is for taxonomy and conservation to collaborate to guarantee the survival of A. glehnii.Developing successful conservation measures requires understanding the genetic diversity and population structure of the species, which is made possible by combining taxonomic and genomic data (Allendorf et al., 2012).The species has been historically isolated and has had minimal gene flow based on the low genetic diversity within populations and the high genetic difference across populations (Eckert et al., 2008).Therefore, it is susceptible to genetic diversity loss due to habitat loss, fragmentation, and over-collection (Karaca & Ince, 2019).Therefore, maintaining genetic connections among populations is crucial to preserving the overall genetic health of a species.
Environmental conservation priorities also depend on identifying genetically different populations (Allendorf et al., 2012).Geographically separated and genetically divergent populations should receive more protection because they reflect different genetic lineages and add to the total genetic diversity of the species (Moritz & Faith, 1998).Furthermore, attempts to maintain and restore habitat may be guided by knowledge of the ecological needs and habitat preferences gathered from this research.Conservationists may identify and safeguard appropriate habitats and put management techniques that support the survival of A. glehnii into practice by knowing the particular environmental conditions that the species prefers.This research emphasizes how crucial it is for taxonomy and conservation to collaborate to educate and direct conservation efforts for A. glehnii.
The results provide a solid basis for developing focused conservation plans that seek to preserve habitat connectivity, safeguard genetic diversity, and guarantee the long-term survival of this threatened plant species.

| CONCLUSION
This research offers fresh perspectives on the foliar epidermal anatomical traits of A. glehnii.While certain variations were observed, such as A. glehnii sunken stomata, the qualitative and quantitative properties of the leaf epidermis were similar to those described for other species in the genus Aster.The findings of this research have consequences for the identification and conservation of A. glehnii and the knowledge of the taxonomy and evolutionary history of the genus Aster.One of the best examples of how important taxonomy is to aiding conservation efforts is the preservation of A. glehnii.Conservationists may develop well-informed plans to maintain and preserve a species and thoroughly understand its conservation status by combining ecological data with taxonomic and genetic data.This research highlights how crucial it is for taxonomists and conservationists to work together to solve the global biodiversity issue and guarantee the survival of the rich and varied flora and fauna.
Identifying genetically different populations is essential for prioritizing conservation efforts and preserving the genetic integrity of the species as a whole.The amalgamation of taxonomy and conservation has facilitated scholars in comprehending the conservation condition and ecological requirements of A. glehnii.Targeted conservation techniques, such as the designation of protected areas, habitat restoration, and invasive species management, have been developed with this understanding in mind.This case study shows the importance of taxonomy in laying the groundwork for successful conservation F I G U R E 1 Foliar epidermal anatomical characteristics and adaxial surface morphology (a-d), along with the abaxial surface morphology (e-i), the anatomical morphology of A. glehnii under scanning electron microscopy.Scale bar is 10 μm.