Abaxial Surface Research Articles

Small Papillae Regulated by SPD25 are Critical for Balancing Photosynthetic CO2 Assimilation and Water Loss in Rice

BackgroundThe leaf epidermis plays an important role in the transmission of light and the regulation of water and gas exchange, which influences the photosynthesis of mesophyll cells. Small papillae (SP) are one of the important structural elements of the leaf epidermis. The mechanism of the effect that small papillae have on rice leaf photosynthetic performance remains unclear.ResultsIn this study, a small papilla deficient 25 (spd25) mutant was isolated from japonica rice Longjin1. Small papillae were absent on the adaxial and abaxial leaf surfaces of the spd25 mutant and the silicon and cuticular wax content in the spd25 mutant leaves decreased. Map-based cloning and functional analysis revealed that SPD25, encoding a guanine nucleotide exchange factor for Rop, is a novel allele of OsRopGEF10. The spd25 mutant showed an increased water loss rate and reduced relative water content. The lower stomatal conductance in the spd25 mutant prevented water loss but decreased the intercellular CO2 concentration and net assimilation rate. The fluorescence parameters showed that the inhibited CO2 assimilation reaction feedback regulated the photochemical electron-transfer reaction, but the performance of Photosystem II was stable. Further analysis indicated that the excess light energy absorbed by the spd25 mutant was dissipated in the form of non-photochemical quenching to avoid photodamage through the optical properties of small papillae.ConclusionsSPD25 regulates the development of small papillae on the surface of rice leaves, which play an important role in balancing photosynthetic gas exchange and water loss. This study deepens our understanding of the physiological mechanisms by which small papillae affect photosynthetic performance.

New report on the invasive Bondar's Nesting Whitefly (Paraleyrodes bondari Peracchi) on oil palm in India

This communication is the new report of the neotropical invasive Bondar's Nesting Whitefly (BNW) , Paraleyrodes bondari Peracchi (Hemiptera: Aleyrodidae)incidence in oil palm in India. A typical feature of BNW infestation is the presence of woolly wax nests on the abaxial surface of oil palm leaflets. The nesting whitefly population was observed to increase phenomenally on oil palm and within a year ie., from 2021 to 2022, a 100 per cent palm infestation was observed. During this period the intensity per palm increased by 24.49 per cent and per leaf increased by 63.28 per cent. Analysis of the partial mitochondrial cytochrome oxidase subunit 1 (CO1) sequences from adult specimens indicated 100% nucleotide identity with Bondar's Nesting Whitefly from coconut.

Taxonomic implications of leaf morphology and epidermal anatomy for 14 species of Gagea (Liliaceae) from Xinjiang, China

BackgroundLeaf morphology and epidermal characters are important for phylogenetic and taxonomic studies of many plants, but there is currently insufficient data to use them to help distinguish species of Gagea, which is a taxonomically difficult genus mainly due to polyploidy and hybridization. Therefore, leaf morphology and epidermal characters of Gagea were studied to assess the characters that can be used to elucidate the taxonomy and systematics of 14 species of Gagea collected in Xinjiang, China. Using light microscopy (LM), six qualitative and three quantitative leaf epidermal anatomical characters were examined for both the adaxial and abaxial surfaces. Hierarchical cluster analysis (HCA) was employed to reveal the similarities based on leaf morphology and epidermal characters of the investigated species.ResultsBasal leaf of these species can be terete or flat, and it is triangle, flat, or circular in transverse section. Anticlinal wall patterns of the leaf epidermal cells were straight and sinuous, and only three species had epidermal hairs. Shape of long cells varies, ranging from quadrangular to irregular. HCA revealed that the 14 species could be divided into two groups. Group A was arranged into three subgroups (A1, A2 and A3), based on the Euclidean distance of 6.96. Subgroup A1 consisted of three species with indumentum; subgroup A2 had four species with sinuous type anticlinal walls; and subgroup A3 comprised of two species with a fistulose basal leaf. Group B included five species with short cells.ConclusionsLeaf morphology and epidermal characters did not differ significantly among populations of the same species in Gagea, whereas they differ significantly among species. Thus, leaf morphology and epidermal characters provide diagnostic information for differentiating G. nigra and G. filiformis; G. altaica, G. jensii and G. alberti, which are morphologically similar species.

Growth Light Quality Influences Leaf Surface Temperature by Regulating the Rate of Non-Photochemical Quenching Thermal Dissipation and Stomatal Conductance

Significant efforts have been made to optimise spectrum quality in indoor farming to maximise artificial light utilisation and reduce water loss. For such an improvement, green (G) light supplementation to a red–blue (RB) background was successfully employed in our previous studies to restrict both non-photochemical quenching (NPQ) and stomatal conductance (gs). At the same time, however, the downregulation of NPQ and gs had the opposite influence on leaf temperature (Tleaf). Thus, to determine which factor plays the most prominent role in Tleaf regulation and whether such a response is temporal or permanent, we investigated the correlation between NPQ and gs and, subsequently, Tleaf. To this end, we analysed tomato plants (Solanum lycopersicum L. cv. Malinowy Ozarowski) grown solely under monochromatic LED lamps (435, 520, or 662 nm; 80 µmol m−2 s−1) or a mixed RGB spectrum (1:1:1; 180 µmol m−2 s−1) and simultaneously measured gs and Tleaf with an infrared gas analyser and a thermocouple or an infrared thermal camera (FLIR) during thermal imaging analyses. The results showed that growth light quality significantly modifies Tleaf and that such a response is not temporal. Furthermore, we found that the actual adaxial leaf surface temperature of plants is more closely related to NPQ amplitude, while the temperature of the abaxial surface corresponds to gs.

First report of powdery mildew caused by Erysiphe corylacearum on hazelnut in Bulgaria.

In June 2020, during an observation of fruit-bearing hazelnut trees (Corylus avelana L., cv. Tonda Gentile), grown in a small private home garden in the region of Kavarna (North-Eastern Black Sea coast of Bulgaria), symptoms of powdery mildew were observed on each of the 15 trees. Compared to the widely spread in Bulgaria powdery mildew caused by Phyllactinia guttata and known with its powdery patches and differing chasmothecia exclusively formed on the abaxial leaf surface, the newly observed disease was characterized by the presence of concomitant pathogen's structures on both the abaxial and adaxial surfaces of the leaves, varying from single pustules to 90% severity on certain leaves, as well as on the husks which were 100% affected. Among the white mycelium, cylindrical conidiophores and singly produced conidia (22-34 x 16-22 µm; n = 50) were found. Scattered or in groups, black spherical chasmothecia (diameter of 85-115 µm; n = 30), possessing 8 to 12 appendages with dichotomous branched apices, were also observed in the autumn. Chasmothecia contained 3 to 5 subglobose asci (45-60 x 34-62 µm; n = 30), each ascus containing 8 hyaline and ellipsoid ascospores (15-22 x 9-16 µm; n = 50). From one field powdery mildew sample DNA was extracted using the Nucleospin Plant II kit (Macherey-Nagel, Germany) and the rDNA ITS region was amplified using primers PMITS1 and PMITS2 (Cunnington, J.H. et al., 2003). The amplicon was sequenced (Macrogen Europe, The Netherlands) and used in a BLAST analysis. This resulted in 100% homology with the ITS sequence of Erysiphe corylacearum. The obtained sequence was different from the ones of Erysiphe pseudocorylacearum (99.20% homology) and Erysiphe coryli-americanae (96.52% homology). The targeted sequence was submitted to GenBank (accession number OQ860748). Based on the symptoms, morphological characteristics and molecular identification, the pathogen was identified as Erysiphe corylacearum. Pathogenicity of the fungus was confirmed under lab conditions (natural day/light regime, 23-25°C) by shaking down conidia from naturally infected leaves on both sides of healthy leaves (2-years plantlets, cv. Tonda Gentile, 3 replicates) and incubation in a moist chamber (plastic bags) for the first 24 hours. First small fluffy white pustules appeared 6-7 days after inoculation, subsequently, the disease was progressing and the pathogen's conidiophores and conidia were morphologically identical to that first observed under natural infections in the private garden. The non-inoculated control plantlets (grown under the same conditions in a separate room) remained symptomless during the entire three weeks testing period. To our knowledge, this is the first report of Erysiphe corylacearum on hazelnut in Bulgaria. In October 2021, the same disease was also found in a hazelnut orchard (1.2 ha) located in the region of Pazardzhik (Central Southern part of the country). Globally, this report indicates the disease's expansion in the Black Sea region since its first observation in Turkey in 2013 (Sezer, A., et al. 2017; Heluta, V.P., et al. 2019; Meparishvili, G., et al. 2019; Rosati, M., et al. 2021) and elsewhere in Europe as well (Beenken, L., et al. 2020; Mezzalama, M., et al. 2021; Voglmayr, H., et al. 2021).

Investigations on the morpho-anatomy and histochemistry of Aconitum napellus L.

Aconitum napellus L. is a popular medicinal plant extensively used in homeopathy. This article provides detailed morphology and microscopy, including the anatomical and histochemical features of the herb, to aid authentication and quality control. In cross-section, the root in secondary growth shows the phloem surrounded by pericyclic fibers and a well-developed xylem. The stem is irregular in outline, displaying unicellular trichomes and many free collateral vascular bundles encircling the pith. The leaf is dorsiventral, hypostomatic with anomocytic and anisocytic stomata, and shows non-glandular trichomes. The floral parts are characterized by uniseriate epidermises, homogeneous mesophyll, anomocytic stomata on the abaxial surface, trichomes, and oval pollen grains. The tissue fragments in powdered herbs show these characteristics and have numerous starch grains with thimble-shaped, linear or star-shaped hilum. The detailed macroscopic and microscopic analysis provided in this study can help in the authentication and quality control of A. napellus raw materials. RESEARCH HIGHLIGHTS: Key anatomical, micromorphological, and microchemical features of Aconitum napellus are described. The results of the study can support the taxonomy of the genus Aconitum. Morphological standardization of the species reported here is helpful in the quality control of this herb.

Anatomical and micromorphological characteristics of Pogostemon heyneanus Benth. (Lamiaceae)

Foliar micromorphological and anatomical characteristics of Pogostemon heyneanus Benth. (Lamiaceae) was investigated in order to describe its comprehensive characterization and its association with the presence of essential oils. The methods used in this study involved several methods such as cross-section using a sliding microtome and epidermal peeling that were observed under light microscope, and foliar micromorphological characteristics that were observed under scanning electron microscope (SEM). Results showed leaf anatomical and micromorphological characteristics that could be useful in species identification and the localization of chemical properties. The leaf epidermal surfaces were characterized by curved to sinuous anticlinal walls (adaxial side) and sinuous anticlinal walls (abaxial side). The diacytic and anisocytic types of stomata were present only on the abaxial surface. The features of the stem is quadrangular and the well-developed collenchyma function. The sclerenchyma cells are present as clusters at the outer layer of vascular bundles and continuously surround the vascular tissue. Then, there were three forms of crystals found, namely star shaped crystals, prismatic crystals and raphides in the pith area. Eight types of trichomes were observed: simple unicellular, simple multicellular, peltate, short-stalked capitate (unicellular head), short-stalked capitate (bicellular head), short-swollen multistalked (unicellular acute head), long-stalked capitate, and long-swollen stalked capitate (disk head) trichomes. The presence of various glandular trichomes on the leaf surfaces may serve as secretory sites where secondary metabolites or essential oils are produced. The findings on the foliar and stem anatomical and micromorphological characteristics are very useful for the medicinal herbs industry as well as being of taxonomic value.

Piper alwynii (Piperaceae), a New Species from the Cordillera del Cóndor at the Border of Peru and Ecuador

Piper alwynii M. A. Jaram. (Piperaceae), a new species occurring in sandstone outcrops of the Cordillera del Cóndor at the border of Ecuador and Peru, is here described and illustrated. Morphologically it shows similarities to species in the Radula clade. Piper alwynii is similar to P. purdiei C. DC. but differs in having leaves pinnately nerved within the lower two thirds of the midvein, nerves pubescent on the abaxial surface, villous peduncles, and spikes 2–2.7 cm long. An identification key for 32 northern South American Piper L. species with small (≤ 10 cm) leaves is presented.

Morphological Characterization of Cannabis sativa L. Throughout Its Complete Life Cycle.

This study extensively characterizes the morphological characteristics, including the leaf morphology, plant structure, flower development, and trichome features throughout the entire life cycle of Cannabis sativa L. cv. White Widow. The developmental responses to photoperiodic variations were investigated from germination to mature plant senescence. The leaf morphology showed a progression of complexity, beginning with serrations in the 1st true leaves, until the emergence of nine leaflets in the 6th true leaves, followed by a distinct shift to eight, then seven leaflets with the 14th and 15th true leaves, respectively. Thereafter, the leaf complexity decreased, culminating in the emergence of a single leaflet from the 25th node. The leaf area peaked with the 12th leaves, which coincided with a change from opposite to alternate phyllotaxy. The stipule development at nodes 5 and 6 signified the vegetative phase, followed by bract and solitary flower development emerging in nodes 7-12, signifying the reproductive phase. The subsequent induction of short-day photoperiod triggered the formation of apical inflorescence. Mature flowers displayed abundant glandular trichomes on perigonal bracts, with stigma color changing from whitish-yellow to reddish-brown. A pronounced increase in trichome density was evident, particularly on the abaxial bract surface, following the onset of flowering. The trichomes exhibited simultaneous growth in stalk length and glandular head diameter and pronounced shifts in color. Hermaphroditism occurred well after the general harvest date. This comprehensive study documents the intricate photoperiod-driven morphological changes throughout the complete lifecycle of Cannabis sativa L. cv. White Widow. The developmental responses characterized provide valuable insights for industrial and research applications.

Morphoanatomical leaf traits of herbaceous species raised in a cronosequence of naturally regenerated areas of tropical deciduous forest

ABSTRACT Plant survival in semi-arid climates depends on morphological, anatomical, and physiological adjustments that determine survival under limiting environmental conditions. In this study, anatomical and morphological characteristics of three herbaceous species with different growth habits were determined: a tall herb, Mesosphaerum suaveolens (tall), Stachytarpheta sanguinea (short), and Jacquemontia evolvuloides (climbing). Fully expanded leaves were collected from three sites in each of three different natural regeneration periods in a seasonally dry tropical forest. Leaf, specific leaf area, epidermis, cuticle, parenchyma, and mesophyll thicknesses; stomatal and trichome densities were measured. All three species have stomata and trichomes on both leaf surfaces and higher densities on the abaxial surface than the adaxial surface. M. suaveolens and S. sanguinea have unusual leaf morphological and anatomical adjustments, with a larger leaf area in the more open and youngest site, but thicker abaxial and adaxial epidermis and mesophyll in the oldest site which has the closest canopy stratum. J. evolvuloides has more usual adjustments, with a smaller specific leaf area and thinner epidermis and isobilateral parenchyma in the youngest site, being better acclimatized to low water availability and high light incidence. Therefore, M. suaveolens and S. sanguinea have unique acclimatization strategies for different environmental conditions.

Lophiolepis (=Cirsium Epitrachys seksiyonu) cinsine ait Türkiye’den yeni bir melez kaydı (Asteraceae, Carduinae)

Lophiolepis Cass., belonging to the tribe Cardueae of the family Asteraceae (subtribe Carduinae) is newly separated from the genus Cirsium Miller in the light of recent molecular studies. It has a high affinity to form interspecific and intersubspecific hybrids under certain circumstances. In the present study, one hybrid combination, Lophiolepis x trifurca (Petr.) Bureš, Del Guacchio, Iamonico &P. Caputo which was previously described as Cirsium x trifurcum Petrak by Petrak in 1914 is newly recorded for Turkish Flora. The hybrid specimens have intermediate characters with parental species; Lophiolepis kosmelii (Adams) Bureš, Del Guacchio, Iamonico & P. Caputo and L. caucasica (Adams) Bureš, Del Guacchio, Iamonico & P. Caputo. Plant samples including parental species were collected from Şavşat district of Artvin province in sympatric populations. These specimens were carefully examined and compared with the putative parents, and morphological character measurements of hybrid plants, as well as parental species were carried out. The samples’ natural habits were photographed, cauline leaf drawings were supplied using a stereomicroscope, leaf micromorphological characters were determined and anatomical characteristics were compared with parents, in detail. In conclusion, intermediate morphological characteristics between L. x trifurca and its parents were determined in terms of features such as cauline leaves, phyllaries, capitula and corolla. It has spines on adaxial sides, and uniseriate multicellular tomentose trichomes in abaxial ones. Cuticle has striate appearance near to the stomata/ trichome bases in the abaxial surface and scale/granules are shown in adaxial parts. This taxon has amphistomatic leaves and dorsiventral mesophyll as in the parental species.

Morphological and anatomical studies of Conamomum vietnamense N.S. Lý & T.S. Hoang: An endemic plant from Vietnam

Abstract. Nhi NTT, Chen TV, Lam DNX, Nguyen DD, Dinh QD, Linh NHK. 2023. Morphological and anatomical studies of Conamomum vietnamense N.S. Lý & T.S. Hoang: An endemic plant from Vietnam. Biodiversitas 24: 5022-5034. Conamomum vietnamense N.S. Lý & T.S. Hoang (Zingiberaceae) is an endemic plant from Vietnam. Information on the anatomical structure of leaves, roots, rhizomes, and the powder characteristics of C. vietnamense has not been reported. This study aimed to combine macro- and micro-morphological analysis to identify C. vietnamense accurately. Twenty fresh plants were randomly collected from the wild habitats in Vietnam were used for the study. Macromorphological characteristics were observed and compared to earlier research. Iodine green-carmine staining was then used to histologically examine the leaves, roots, and rhizomes. The powdered rhizome and leaf features were described via a microscope. Macromorphologically, C. vietnamense is characterized by its stout stilt roots, short petioles, oblong-lanceolate leaf blades with lightly plicate, inflorescences with obovoid, and narrowly ovate bracts, hairy underside bracteoles, bilobed calyx, yellow flowers with broadly obovate, glabrous, trilobed labellum. Micromorphologically, the anatomical features of leaves, roots, and rhizomes have similarities with those of Zingiberaceae species. The tetracytic stomata was observed on both leaf surfaces. The stomatal indexes on the abaxial and adaxial surfaces of the leaves are 8.81±0.55% and 0.1±0.06%, respectively. Calcium oxalate crystals were found in the leaf. Starch grains and reticulate xylem vessels were present only in rhizome powder. These findings are important characteristics for identifying C. vietnamense.

First report of areolate mildew of cotton, caused by Ramulariopsis pseudoglycines in Mississippi.

In August of 2022, cotton (Gossypium hirsutum L.) growing in several north central Mississippi counties was observed to exhibit yellowish lesions on the adaxial leaf surface with white powdery fungal growth on the corresponding abaxial surface. By the end of the 2022 growing season, 19 Mississippi counties were observed to have infected cotton. Symptomatic leaves were collected from affected plants, sealed in plastic freezer bags, stored on ice in a cooler, and transported to the laboratory. Prior to isolation, the pathogen was microscopically examined and determied to be morphologically similar to the description of Ramulariopsis spp. (Ehrlich and Wolf 1932). Using a sterile needle, conidia were transferred to V8 medium amended with chloramphenicol (75 mg/liter) and streptomycin sulfate (125 mg/liter) and incubated in the dark at 25°C. After 14 days, the colony diameter was measured, and morphological characteristics were consistent with previous descriptions (Videira et al. 2016; Volponi et al. 2014). On V8 medium, the 7 mm diameter colonies grew raised, lumpy, and lobed, with iron-grey coloration. The mycelia were hyaline, septate, branched, and 1 to 3 μm in diameter. Conidia ranged from 2.8 to 25.6 μm in length and 1.0 to 4.9 μm in width (x = 12.8 × 3.1 μm; n = 20). Pure cultures were obtained on V8 medium, and DNA was extracted from a 14-day-old-culture. TW098-22, a representative isolate, was amplified, and sequenced targeting the internal transcribed spacer (ITS), translation elongation factor 1-α (TEF 1-α), and actin (ACT) genes as described by Videira et al. (2016). The consensus sequences were deposited in GenBank (accession no. OQ653427, OR157986, OR157987). BLASTn query of the NCBI GenBank showed 100% identity of the 483-bp (ITS) and 706-bp TEF 1-α sequences from TW098-22 with Ramulariopsis pseudoglycines CPC 18242 (type culture; Videira et al. 2016). Koch's postulates were performed after multiplying individual colonies by streaking on V8 medium as above. Culture plates were subsequently incubated at 25°C for 14 days in the dark. Colonies were aseptically transferred to 50 ml centrifuge tubes containing 50 ml of autoclaved reverse osmosis (RO) water amended with Tween 20 (0.01%). The resulting inoculum suspension was adjusted to 13.5 × 105 conidia/ml using a hemocytometer. The foliage of five, 25-day-old cotton plants were sprayed with 10 ml of the suspension and a plastic bag was placed over each plant to maintain humidity for 30 days. Five plants were sprayed with sterilized RO water to serve as controls. Plants were incubated in a growth chamber at 25°C and ~70% relative humidity with 16:8 h of light:dark. Thirty days post-inoculation, foliar symptoms and signs were observed on all inoculated plants including small necrotic lesions and white powdery growth. Control plants remained asymptomatic. The trial was repeated. When reisolated, the colony and conidia morphology and DNA sequence (ITS) were consistent with the description of the original field isolate. Areolate mildew of cotton can be caused by two species of Ramulariopsis: R. gossypii and R. pseudoglycines (Videira et al. 2016). The two species have been reported in Brazil (Mathioni et al. 2021); however, this is the first report of R. pseudoglycines in the United States. In addition, even though areolate mildew has previously been reported from much of the southeastern U.S. (Anonymous 1960), the report herein serves as the first description of R. pseudoglycines in Mississippi and U.S. cotton.

Erysiphe elevata causing powdery mildew on Eucalyptus urophylla × E. camaldulensis in China.

Eucalyptus urophylla × E. camaldulensis, named Chiwei eucalypt, is a hybrid species widely used in China. Many of its clones are cultivated for afforestation due to cold tolerance, high yield, high strength and disease resistance. Clone LH1 is planted extensively for its high stability and machinability in South China. In December 2021, severe powdery mildew signs were observed on clone LH1 in Zhanjiang, Guangdong (N28°8'29"; E110°17'5"). Whitish powder principally appeared on both abaxial and adaxial leaf surfaces. All plants were infected within about a week and above 90% leaves were diseased, which resulted in abnormal growth and shrinkage of leaves. Hyphae with single, lobed appressoria were hyaline, septate, branched, 3.3-6.8 µm (ave. 4.9 µm, n>50) wide. Conidiophores with a straight to flexuous foot-cell (14.7-46.1×5.4-9.7 µm, ave. 25.8×7.9 µm, n>30) were erect, hyaline, 2-septate, unbranched, 35.4-81.8 × 5.7-10.7 (ave. 56.7×8.7 µm, n>50). Conidia were solitary, hyaline, cylindrical to elliptical, 27.7-46.6 ×11.2-19.0 (ave. 35.7×16.6 µm, n>50). Chamothecia were not found on infected trees. The further identification was confirmed by partial sequences of internal transcribed spacer (ITS), large submit rRNA gene (LSU), Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), glutamine synthetase (GS), and RNA polymerase II second largest subunit (RPB2) gene. A very small amount of mycelia and spores from voucher specimens CCAS-ASBF-1 and CCAS-ASBF-2 were deposited in the herbarium of Guangdong Ocean University. Specimens were PCR amplified and sequenced with primer pairs ITS1/ITS4 (White et al 1990), LROR/LR7 (Moncalvo et al 1995), PMGAPDH1/PMGAPDH3R, GSPM2/GSPM3R and PmRpb2_4/ PMRpb2_6R (Bradshaw, et al. 2022), respectively. BLASTn results showed that ITS (OP270019 and OQ380937), LSU (OP270018 and OQ380938), GAPDH, GS and RPB2 (OQ414445- OQ414450) were above 99% identical with those of E. elevata on Catalpa bignonioides (ITS: AY587013) (Cook et al 2004), Plumeria rubra (ITS: MH985631) (Yeh et al 2019), Cerbera manghas (ITS: MZ379159; LSU: MZ379160) (Mukhtar et al 2022), and Eucalyptus camaldulensis (LSU: LC177375-6) (Meebon et al. 2017), and above 99% identical with those of Erysiphe vaccinii FH00941201 on Vaccinium corymbosum (ITS: ON073869; RPB2: ON119159; GS: ON075687) and FH00112205 on V. vacillans (ITS: ON073870; GAPDH: ON075646) (Bradshaw et al 2022). This is the first sequence data for non rDNA of E. elevata. In an ITS tree phylogenetic analysis with Maximum likelihood (ML) method showed the fungus clustered in a highly supported clade with E. elevata and E. vaccinii. In a multi-locus tree, E. elevata grouped in a sister position to E. vaccinii FH00941201. Thus, the pathogen was identified as E. elevata based on morphology, DNA BLASTn and phylogenetic analysis (Braun and Cook 2012). Pathogenicity tests were conducted on healthy leaves of 1-year-old potted plants. Ten leaves were cleaned with sterile water, inoculated by gently dusting conidia from single lesion on the naturally infected leaves, and then covered with plastic bags containing wet absorbent cotton. Non-inoculated leaves served as controls. Symptoms developed on all inoculated leaves 3 to 5 days after inoculation, and the fungus was identical to the original fungus on the infected leaves, whereas control plants remained symptomless. This is the first report of powdery mildew caused by E. elevata on Eucalyptus sp. from China. This finding is helpful for land managers to diagnose and control the disease.

Comparative Morphology, Anatomy and Phytochemistry of Cyrtosperma senegalense (Schott) Engl. and Alocasia macrorrhizos L. (Araceae)

Morphological, anatomical and epidermal studies were carried out on two species of Araceae, Cyrtosperma senegalense (Schott) Engl. and Alocasia macrorrhizos L. to investigate the taxonomic value of their similarities and differences. Morphological features were visually observed. Fresh specimens were dehydrated, wax embedded, mounted, microscopically observed and micrographed. Basic similarities were found in their leaf shape, venation, inflorescence and spathe, seeded fruits, scattered vascular bundles, possession of aerenchyma, and presence of stomata on the abaxial and adaxial leaf surfaces. Conversely, the presence of prickles and sparseness of raphide idioblasts containing a raphide bundle each in C. senegalense distinguishes it from A. macrorrhizos which has abundant raphides. Phytochemical screening shows differences in their alkaloids, saponin, triterpenoids, steroids and glycosides contents. Though these preliminary studies yielded data that revealed their relationship and phytochemistry, further investigations of their cytology using electron microscopy and molecular biology are needed for more diagnostic data to distinguish them from each other and add more incite to their potential in drug discovery.

Epidermal and subepidermal changes during the formation of hairy galls induced by Eriophyidae on Avicennia schaueriana leaves.

Leaf-galling Eriophyidae (Acarina) may promote simple or complex alterations in the organs of their host plants, such as an increase in indumentum density or the reorganization of epidermis and ground system tissue patterns. To test if hairy galls of Eriophyidae on Avicennia schaueriana (Acanthaceae) are related to complex changes, leaf galls in distinct developmental phases were compared to non-galled leaves using anatomical, histochemical, and histometric analyses. Quantitative comparisons of preferential gall induction sites and gall area according to distinct leaf portions were made to evaluate if the impacts of gall formation can be related to the distinct potentialities of leaf microsites. The apical portion of the leaves and leaf margins were the sites with the highest occurrence of galls, but no relationship was detected between gall area and induction site. The gall anatomy revealed that epidermal features are influenced the most with the development of abnormal stomata and projected or sunken salt glands. The most striking change is the neoformation of elongated filiform trichomes on the abaxial surface (where the mites occur) that accumulate reducing sugars and proteins. The filiform trichomes may protect the inducers against abiotic stressors and enemies, and the primary metabolites that accumulate are important foods for mites. The mesophyll has simple alterations, only in the spongy parenchyma. Complex alterations occur only in abaxial epidermal cells close to feeding sites of the inducer. The number of inducers per gall seems to be the most important influence on gall size, since gall area is not related to the position in the leaves.

First Report of Puccinia menthae Causing Leaf Rust on Peppermint (Mentha x piperita) in Mexico.

Peppermint (Lamiaceae) is an aromatic herb with culinary, medicinal, and industrial properties. In June 2022, symptoms and signs of foliar rust were observed in four commercial fields of peppermint (Mentha × piperita) in San Buenaventura Tecalzingo, San Martín Texmelucan, Puebla, Mexico (19°14'34.0"N 98°27'25.4"W; 19°14'16.7"N 98°27'21.4"W; 19°14'37.0"N 98°27'07.7"W; 19°15'00.6"N 98°26'54.7"W). Two diseased plants were collected at each site. The disease was present in 50% of the plants and the damaged foliar tissue was under 17%. Initial symptoms included small chlorotic spots on the adaxial surface of the leaves, which later spread to form a necrotic area surrounded by a broad chlorotic halo. Necrosis developed only in the presence of abundant reddish-brown pustules on the abaxial surface of the leaf, while smaller pustules were observed on the adaxial surface. The signs were detected as numerous reddish-brown pustules on the abaxial surface of the leaves. The infected leaves of all samples showed subepidermal uredinia, erumpent, with hyaline and cylindrical paraphyses. Urediniospores (n = 50) were hyaline to light brown, echinulate, with two germinative pores, obovoid (16.5-26.5 × 11.5-25.5 μm, mean ± SD = 22 ± 1.6 × 19 ± 0.4 μm and 0.6 μm of wall thickness), individually supported on pedicels. Morphological characteristics aligned most closely with the description of Puccinia menthae by Kabaktepe et al. (2017) and Solano-Báez et al. (2022). A voucher specimen was deposited in the Herbarium of the Department of Plant-Insect Interactions at the Biotic Products Development Center of the National Polytechnic Institute under accession no. IPN 10.0115. From one sample, genomic DNA was extracted, and the 28S gene region of rDNA was amplified by a nested PCR using the primer sets Rust2inv (Aime, 2006) and LR6 (Vilgalys and Hester, 1990), and Rust28SF (Aime et al., 2018), and LR5 (Vilgalys and Hester, 1990) for the first and second reactions, respectively. The obtained sequence (GenBank accession No. OQ552847) showed 100% homology (902/1304bp) with the type-specimen sequence of P. menthae (DQ354513) from Cunila origanoides from USA (Aime, 2006). A phylogenetic analysis using Maximum Likelihood including a published 28S dataset for Puccinia species was executed and the isolate IPN 10.0115 was grouped into a clade of P. menthae with bootstrap support value of 100%. Pathogenicity was assessed by spraying a suspension of urediniospores (1×104 spores/ml) of the isolate IPN 10.0115 onto six healthy peppermint plants (Mentha × piperita) that were 30 days old, while six other plants were sprayed with sterile distilled water. All plants were kept in a wet chamber for 48 h at temperatures from 28±2°C and relative humidity of 95%, after which the plastic bag was removed. All inoculated plants developed disease symptoms after 15 days, whereas the control plants remained symptomless. The pathogenicity assay was conducted twice with similar results. The morphology of the pathogen recovered from the pustules of the inoculated plants was identical to that originally recollected, thus fulfilling Koch'postulates. To our knowledge, this is the first report of Puccinia menthae causing leaf rust on Mentha × piperita in Mexico. This species has been previously identified using morphological characteristics in Brazil, Canada, Poland, and USA on Mentha × piperita (Farr and Rossman, 2023). Since the disease defoliates peppermint plants reducing yield, further information on disease management is needed.

Anatomical and histochemical studies of vegetative organs of Stylosanthes capitata Vogel

The Fabaceae family is widely distributed throughout the world. Among the genera of this family, Stylosanthes Sw., in addition to counting some species used as fodder, also presents species used in traditional medicine. Stylosanthes capitata Vogel, known as arcançú or estilosantes, stands out from the other species of the genus for having a high content in leaf protein and used in traditional medicine. The general objective of this work is to carry out the anatomical characterization of the root, stem and leaves and histochemical study of the leaves of S. capitata. Usual methods in plant anatomy were used for the preparation of analyses in optical microscopy of semi-permanent slides containing cross sections of vegetative organs, and paraderms of the leaflet blade of S. capitata. Histochemical tests were also carried out in order to locate the metabolites in cross sections of leaflet blades. The microscopic evaluation allowed the identification of characteristics in the root, such as the presence of sclerenchyma; stem with bicollateral vascular bundle, presence of prismatic crystals; on the petiole with 1–3 layers of palisade parenchyma and bicollateral vascular bundle; and leaf blade with paracytic and anisocytic stomata on the abaxial surface, differentiation in the layers of palisade parenchyma and spongy parenchyma, and absence of secretory appendages in all structures analyzed. Through histochemical techniques, the presence of phenolic compounds, lipophilic compounds, lignin, and proteins was evidenced. The results are fundamental for the pharmacobotanical standardization of the studied specie.

Viola austroyunanensis (Violaceae), a new species from Yunnan province of China

Viola austroyunnanensis is described and illustrated as a new species from southeastern Yunnan province of China. According to morphological studies, it belongs to Viola sect. Diffusae, and is related to V. fargesii, from which it differs by its stolons, petioles, stipules, abaxial leaf surface and sepals being all glabrous (vs. white puberulous), later petals glabrous (vs. beard), flower color usually blue-purple (vs. white); corolla throat nearly white (vs. yellow). But molecular phylogenetic results based on ITS dataset show that V. austroyunnanensis belongs to Viola sect. Adnatae. The systematic relationship of V. austroyunnanensis needs further research.

Characterization of morphological, micromorphological, anatomical structures and matK gene-based identification of aromatic litsea (Litsea cubeba)

Abstract. Aini IN, Wisanti. 2023. Characterization of morphological, micromorphological, anatomical structures and matK gene-based identification of aromatic litsea (Litsea cubeba). Biodiversitas 24: 4557-4567. Aromatic litsea or krangean (Litsea cubeba (Lour.) Persoon) has potential as a drug. L. cubeba's status based on the IUCN red list is the least concern. This research aimed to (i) characterize morphology, micromorphology, and anatomy; (ii) indetify L. cubeba species based on DNA barcodes. The research samples were collected in the Mt. Anjasmoro, East Java, Indonesia at three different altitudes. Data in the form of various characters were analyzed using the one-way ANOVA method to determine the significance of the difference. The statistical test analysis of the quantitative character of L. cubeba showed a significant difference between heights (? = 0.05). The results showed that the characterization of L. cubeba includes (i) morphology: structure of lenticels, color, and substance that coats the lower surface of leaves, type of flower, fruit taste, and aroma; (ii) micromorphology: glands lining the abaxial surface of the lamina, trichomes on both surfaces of the lamina, structure of abaxial epidermal cells, the shape of pollen, shape and distribution of exin (iii) anatomy: cuticle thickness, epidermal cell shape, and presence of secretory cells in the lamina. The molecular identification in the form of L. cubeba barcode DNA based on the matK gene marker matched the Litsea cubeba sequence in NCBI (AB259073.1).