Leaf Margins Research Articles

The Purple leaf (Pl) Alleles, Plw and Pli, Regulate Leaf Color Development Independently from the Pb Gene of Purple pericarp (Prp) in Rice

Color development in various rice organs results from the complementary expression of genes involved in anthocyanin biosynthesis. The Purple pericarp (Prp) trait and the Purple leaf (Pl) trait both display epistasis, relying on the complement of the Pb and Pp genes for pericarp coloration and the Pl and Pp genes for leaf coloration, respectively. However, there is still genetic uncertainty in identifying the genes responsible for the various color expressions and intensities of rice grain pericarp and leaves. In this study, we characterized the inheritance patterns of color development and the mode of anthocyanin pigments in rice by crossing two parental mutant lines. YUM051, exhibiting dark purple leaves (Plw) and purple pericarp (Prp), was crossed with YUM144, which displayed light purple leaves (Pli) and a white pericarp (prp). The F1 plants exhibited dark purple leaves with purple pericarps, indicating the dominant nature of the purple leaf (Pl) and purple pericarp (Prp) traits. The rice Prp traits display a complementary interaction, reflected in a 9:7 ratio of purple to white pericarp. However, the Prp trait followed Mendelian segregation with a 3:1 ratio of purple to white pericarp in this cross, indicating homozygous dominant Pp alleles in both parental plants. Meanwhile, the segregation of the purple leaf color in the F2 generation of this cross followed complementary inheritance, exhibiting a 9:7 segregation ratio between purple leaves and greenish leaves with purple leaf margins. Moreover, the co-segregation of Prp and Pl traits in the cross between YUM051 (Plw) and YUM144 (Pli) plants did not adhere to the Mendelian 9:3:3:1 independent assortment ratio, confirming that the Pl gene and Pb gene are linked on the same chromosome. Cyanidin-3-O-glucoside (C3G) was detected in the leaves of all progeny resulting from the Plw and Pli cross. However, C3G was exclusively identified in the seeds of offspring carrying the dominant Pb gene. Therefore, the Plw and Pli alleles are Pl genes responsible for purple leaf color, while the Pb gene is responsible for purple pericarp color in rice; these genes function independently of each other.

An Overview of the History of Bellevalia (Asparagaceae: Scilloideae) Infrageneric Classifications and Evaluation of Cilia at Leaf Margins to Determine the Position of Species in the Classification

Bellevalia Lapeyr. (Asparagaceae) underwent numerous changes in infrageneric classification based on morphological characteristics between 1854 and 1980. In 1939, a comprehensive classification was proposed, based on the morphological features of the flowers and leaves of 45 species. This classification, which was unique at the time, divided the genus into four sections and six subsections. In 2021, a phylogenetic study was conducted on 14 Bellevalia species using four plastid genes. The study led to a revised infrageneric classification determined by the presence or absence of cilia at the leaf margins. In this study, morphological characteristics, particularly the presence of cilia at the leaf margins, were assessed for of 40 Bellevalia species and categorised according to the recent infrageneric classification. The results showed that 13 species exhibited glabrous or smooth leaf margins while 27 displayed non-glabrous leaf margins. Three types of cilia were observed in non-glabrous species: a) ribbon-shape, b) turbinate or conical, and c) papilla. Notably, the species with glabrous leaf margins were exclusively found in the Irano-Turanian region, whereas non-glabrous species were distributed throughout the Irano-Turanian, Mediterranean and Saharo-Sindian regions.

Tirpitzia meiguensis (Linaceae), a new species from southwest Sichuan (China)

Tirpitzia meiguensis, a new species from Meigu County, Sichuan Province, China, is herein described and illustrated. Although its herb-like semi-shrub habit, toothed leaf margins, and seeds without a membranous wing are not characteristics that are seen in the three formerly-reported Tirpitzia species, other characteristics are morphologically related to T. sinensis; these include white flowers, terminal cymes, a four-loculed ovary with two ovules per locule, and a four-valvate capsule. Furthermore, phylogenetical analysis based on the internal transcribed spacer sequences of nuclear genes confirmed that this new species is clearly a member of Tirpitzia.

First report of coffee leaf spot caused by Curvularia geniculata

AbstractDuring May and June 2021, the commercially grown coffee, variety SL34, grown commercially, developed necrotic, irregularly shaped spots on 1–5% of leaves. These plants were under greenhouse culture in the area of Goheung in South Korea (34°47′N, 127°46′E). The leaf spots, often observed at leaf margins, changed with time from reddish‐brown coloration to dark brown lesions with yellow halos. Morphological and molecular analysis confirmed the fungus from the lesions as Curvularia geniculata. The pathogenicity of the fungal isolate was verified by Koch's postulates on coffee plants grown under greenhouse conditions. These findings support that C. geniculata causes leaf spot disease in coffee plants and, to our knowledge, is the first time this disease has been reported in the world.

An Inverse Scaling Relationship between Stomatal Density and Mean Nearest Neighbor Distance: Evidence from a Photinia Hybrid and One of Its Parents.

Stomata are involved in transpiration and CO2 uptake by mediating gas exchange between internal plant tissues and the atmosphere. The capacity for gas exchange depends on stomatal density (SD), stomatal size, and pore dimensions. Most published work on stomatal quantification has assumed that stomatal distribution and stomatal density are spatially homogeneous across the leaf, but this assumption has been seldom tested. We selected 32 leaves from a Photinia hybrid, Photinia × fraseri 'Red Robin', and one of its parents, P. serratifolia. For each leaf, the leaf surface was divided into three or four equidistant layers along the apical-basal axis, and, in each layer, two positions, one closer to the midrib and the other closer to the leaf margin, were further selected. We calculated SD and mean nearest neighbor distance (MNND) for each lamina section and tested the scaling relationship between SD and MNND of the sampled stomatal centers using reduced major axis protocols. In addition, we calculated the stomatal aggregation index (SAI) for each lamina section to examine the spatial arrangement of stomata at the given size of field of view of 1.2 mm × 0.9 mm. We observed that SD decreased from the lamina apex towards the base for central lamina areas but varied little at leaf margins. An inverse scaling relationship between SD and MNND was observed for both species. This relationship could be used for SD estimation using the rapidly estimated trait, MNND. SAI did not vary significantly throughout leaf lamina, and the numerical values of SAI for all fields of view were greater than one, which indicates significant spatial repulsion between stomata. The study suggests that SD varies across leaf lamina to fine-tune plant water use and maximize carbon gain. However, spatial structures of stomata from different lamina sections exhibit similar patterns (i.e., spatial inhibition between stomata at small scales), probably due to hierarchical leaf vein patterns.

Favorite Parts of a Single Leaf for Giant Flying Squirrels to Eat in Three Species of Food Trees.

To examine the effect of leaf chemical composition on selective herbivory by the Japanese giant flying squirrels (Petaurista leucogenys), we measured and compared the total phenolic, glucose, and water contents of leaves among their main food tree species, deciduous Quercus acutissima, and evergreen Q. sessilifolia and Phonitia serratifolia. Leaves of these three tree species were available in the warm season (April to October), but the flying squirrels mostly preferred the leaves of Q. acutissima, having higher glucose and water contents than those of the other two tree species. In the cold season (November to the next March), the two evergreen tree species were available, and the flying squirrels used both leaves without any apparent influence of the chemical compositions. On the other hand, the favorite parts of a single leaf differed among the three tree species. Flying squirrels dropped the individual leaves after partial consumption. Their feeding marks on the dropped leaves were distinguished into four types: apical, basal, central, and marginal parts of consumption. The basal parts of consumption were most frequent in Q. acutissima leaves in which more water was contained at the basal part, and the central part consumption followed, which may be related to a lower phenolic content and more glucose and water at the leaf center than its margin. In contrast, the apically consumed leaves dominated in Q. sessilifolia, with relatively homogeneous leaf chemical distribution except for more water at the center. In P. serratifolia, leaves consumed at the center were frequent, but those with marginal consumption were also observed, which may be related to its specific chemical distribution with less phenolics and more glucose at the leaf margin. Thus, the chemical distributions within the single leaf differ among tree species, and the flying squirrel's selectivity of the tree species and the part of each leaf depends partly on the relative compositions of preferable glucose and water and unpreferable phenolics.

A method for estimating paleotemperatures from pollen assemblages applied to the quantification of the Early Holocene warming in Central Brazil

This study presents a method for the quantification of paleotemperatures from pollen records based on the predominant leaf margin trait of the genera represented in the pollen assemblages. The method presented here uses the well-known and widely used relationship between leaf margin and mean annual temperature, which is commonly applied to macrofloras to reconstruct paleotemperatures. Here, genera occurring in the arboreal vegetation of Central Brazil were analyzed respective to the presence or absence of species bearing toothed leaves. Using floristic surveys, a correlation between the proportion of genera without toothed species and the mean annual temperature was investigated. A positive linear correlation between these two variables was found for forest sites, but not for the arboreal savannas. The equation derived from the linear regression between the two variables - proportion of genera without toothed species and mean annual temperature (MAT) - was applied to pollen assemblages collected on forest sites. The equation was used to calculate estimated MATs for surface samples in order to test the validity of its application to pollen assemblages. The equation was then applied to fossil records to estimate paleoMATs for two Brazilian sites located respectively at 15.5° and 28° of latitude, during the Pleistocene-Holocene transition (between 13.6 and 10 kyr cal BP). While MAT increases of around 3 °C were found for the higher latitude site, no significant differences between final Pleistocene and early Holocene MATs were found for the near-equatorial site.

The trait co-variation regulates the response of bryophytes to nitrogen deposition: A meta-analysis

The nitrogen deposition has the potential to alter the trait composition of plant communities by affecting the fitness and physiological adaptation of species, consequently exerting an influence on ecosystem processes. Despite the importance of bryophytes in nutrient and carbon dynamics across different ecosystems, there is a lack of research examining the relationship between nitrogen deposition and the co-variation of bryophyte traits. To address this gap, a meta-analysis was conducted using data from 27 independent studies to investigate potential associations between trait co-variation of bryophytes and nitrogen deposition. The results revealed that interspecific variability regulates the influence of nitrogen deposition on bryophytes by affecting trait co-variation. Multiple correspondence analysis identified six combinations of closely related traits. For example, species with unbranched main stems frequently exhibit robust leaf midribs, leading to leaf wrinkling and leaf clasping around the stem as a response to water loss. Some weft or mat species tend to obtain resources (nitrogen) through their scale hairs on the main stem. Some species with narrow leaves require leaf teeth to maintain a normal leaf shape. The subgroup analyses indicated that certain traits, including unbranched main stem, changes in leaf morphology, robust leaf midrib, main stem without scale hairs, narrow leaf, leaf margin with teeth, undeveloped apophysis, and erect capsule minimize interaction with pollutants and represent a resource strategy. Conversely, functional traits representing a resource acquisition strategy, such as branched main stem, no changes in leaf morphology, short and weak leaf midrib, main stem with scale hairs, broad leaf, leaf margin without teeth, developed apophysis, and non-erect capsule increase pollutant exposure. Overall, our results suggest that anthropogenic global change may significantly impact bryophytes due to changes in their individual physiology and colony ecological indicators caused by increased nitrogen deposition.

Beyond aesthetics: Integration of textural groups of tropical ornamental shrubs into urban planting designs

Shrubs are popularly incorporated to establish green infrastructure in urban spaces. We argue that the functions provided by shrubs could be further enhanced by giving due consideration to their leaf morphological characters. Therefore, our objective was to recognise how the different morphological characters of leaves, listed as contributing to determining the plant texture in literature, would collectively contribute to recognizing textural groups of plants, and further, to define each of these groups into either coarse, medium, or fine textural categories using ornamental shrubs. We investigated the quantitative and qualitative leaf morphology of 30 tropical ornamental shrubs in the Peradeniya area. According to our analysis, leaf area, petiole length, and internodal distance have significantly contributed to the separation of shrubs into three textural groups; fine, medium and coarse, and were considered as preliminary characters that determine the texture. Leaf hair related characters viz., hair densities on upper and lower surfaces, and the length of hairs on both surfaces, together with qualitative morphological characters, viz., leaf margins, leaf arrangement, and prominent venation were identified as secondary characters that contributed to defining textural groups. Shrubs with coarse texture possess significantly larger leaves, longer petioles and internodal distances compared to fine textured group. Our recommendation is to consider plant textural groups as a criterion in the selection of plants for planting designs during the establishment of green infrastructure in urban spaces, enabling the obtaining of benefits beyond aesthetics, which include other functional, health and environmental benefits, to improve the quality of life of city dwellers under the context of limited urban green spaces.

A new species of Begonia section Baryandra from Zamboanga Peninsula, Southwestern Philippines

A new species of Begonia sect. Baryandra, B. sebodensis, from Zamboanga del Norte, southwestern Philippines is described and illustrated. Begonia sebodensis is morphologically similar to B. anisoptera in obliquely ovate to widely ovate leaves, four-tepaled staminate and pistillate flowers and three locular ovary but differs in glabrescent stipules, sericeous petioles, leaf margins distantly serrate and ciliate, many-flowered inflorescences, capsule wings subequal and flat. Following IUCN criteria, we propose B. sebodensis as Endangered (EN).

Combined Transcriptomic and Metabolomic Analyses of Defense Mechanisms against Phytoplasma Infection in Camptotheca acuminata Decne

Camptotheca acuminata Witches’-broom disease (CaWB) is the most destructive disease affecting C. acuminata in China. Previous studies on CaWB have failed to clarify the incidence pattern in C. acuminata after infection with phytoplasma. The time interval between phytoplasma infection of C. acuminata and the onset of Witches’-broom symptoms in C. acuminata was very long. C. acuminata inoculated with CaWB showed leaf margin scorching symptoms at 4 weeks in inoculated leaves. At 16 weeks after infection (WAI), old leaves were shed, while new leaves showed a mild leaf margin scorch; at 28 WAI, typical symptoms appeared. Transcriptomic and metabolomic analyses of the three sampling periods revealed 194 differentially expressed genes, mainly enriched in MAPK signaling, plant–pathogen interaction, phenylpropanoid biosynthesis, starch and phenylpropanoid biosynthesis, and phenylpropanoid biosynthesis pathways. The expression of calcium-dependent protein kinase (CDPK), β Ketoacyl-CoA Synthase1/10 (KCS1/10), and WRKY22/29 genes in the plant–pathogen interaction pathway significantly increased, indicating that they may be key genes in the CaWB phytoplasma-mediated maintenance of ROS homeostasis. Moreover, isochlorogenic acid B, atractylenolide II, and 3-methoxybenzoic acid were found, which might serve as signaling or functional substances in the defense response. Our results provide novel insights into the pathogenesis of CaWB and the defense response of C. acuminata under the influence of phytoplasma. Additionally, we identified potential candidate genes related to the defense response of C. acuminata, laying the foundation for further research.

First report of black rot disease in Eruca vesicaria subsp. sativa caused by Xanthomonas campestris pv. campestris in Belgium.

Eruca vesicaria subsp. sativa (Mill.) Thell. (arugula or rocket) is a leafy vegetable originating from the Mediterranean region primarily being sold in bagged salads. From 2014 to 2017, plants (cv. Montana) exhibiting blackened leaf veins and irregular V-shaped chlorotic to necroic lesions at the leaf margins were observed in commercial greenhouses in Flanders, Belgium (Figure S1A). Symptoms started after harvest of the first cut, indicating that leaf injury favours disease development. By the last cut, infections had spread uniformly across the plots, with symptoms advanced to the point where harvesting was no longer profitable. Excised surface-sterilized necrotic leaf tissue and seeds were homogenized in phosphate buffer (PB), followed by dilution plating on Pseudomonas Agar F containing sucrose. After four days at 28°C, bright yellow round, mucoid, convex Xanthomonas-like colonies were obtained, both from leaves and seeds. For confirmation, DNA was extracted from pure cultures after which a partial fragment of gyrB was amplified and sequenced (Holtappels et al. 2022). Amplicons were trimmed to 530 nucleotides (Genbank ON815895-ON815900) according to Parkinson et al. (2007) and compared with the NCBI database. Strain GBBC 3139 shares 100% sequence identity with Xanthomonas campestris pv. campestris (Xcc) type strain LMG 568 and with RKFB 1361-1364, isolated from arugula in Serbia (Prokić et al. 2022). The other isolates from Belgian rocket - GBBC 3036, 3058, 3077, 3217 and 3236 - all have a gyrB sequence 100% identical to that of Xcc strain ICMP 4013, among others. To determine the genetic relatedness to other pathogenic Xc strains, the genomes of GBBC 3077, 3217, 3236 and 3139 were sequenced using a MinION (Nanopore) and non-clonal sequences were submitted to NCBI (BioProject PRJNA967242). Genomes were compared by calculating Average Nucleotide Identity (ANI). This revealed that the Belgian strains cluster together with Xc isolates originating from Brassica crops and separate from strains identified as Xc pv. barbareae, pv. incanae and pv. raphani (Figure S2A). Their designation as pv. campestris is supported by maximum likelihood clustering of concatenated gyrB-avrBs2 sequences (EPPO, 2021; Figure S2B,C). Finally, pathogenicity was verified on five-week-old rocket 'Pronto' plants grown in a commercial potting mix by cutting the leaves along the midrib with scissors dipped into a suspension of 108 cfu/ml of each strain or PB as control (4 plants/strain). Plants were kept in closed polypropylene boxes for 48 hr to support high humidity and facilitate infection. They were then maintained at 25 ± 2 °C. Lesions like those observed on commercial plants developed on the inoculated leaves within one week (Figure S1B). Bacterial colonies reisolated from symptomatic tissue were identified based on gyrB as the strains used for inoculation, thereby fulfilling Koch's postulates. To the best of our knowledge, this is the first report of black rot disease in arugula caused by Xcc in Belgium. Previously, Xcc on arugula has been reported in Argentina, California and Serbia as well (Romero et al. 2008; Rosenthal et al. 2017; Prokić et al. 2022). Arugula being a minor crop in Belgium, challenged by Xcc infections and strong import competition, many growers have abandoned the sector in recent years. Therefore, this study makes a strong case for early detection of disease symptoms and timely application of relevant management strategies in vulnerable crop settings.

First Report of Exserohilum rostratum Causing Leaf Blight on Broccoli (Brassica oleracea var. italica) in China.

Broccoli (Brassica oleracea var. italica) is not only an important crop worldwide with a large amount of production and consumption annually, but also rich in biologically active compounds (Surh et al., 2021). In November 2022, an unknown leaf blight was observed in the Broccoli planting area, Wenzhou City of Zhejiang Province (28.05 °N, 120.31 °E). Symptoms initially occurred at the leaf margin with yellow to gray lesions that were irregular and wilting. Approximately 10% of the surveyed plants were affected. To determine the pathogen, leaves with blight were collected randomly from five B. oleracea plants. Tissue blocks (3×3 mm) from diseased leaf portions were disinfected with 75% ethanol, rinsed three times with sterilized water, placed aseptically onto potato dextrose agar (PDA) medium, and incubated for 5 days at 28℃ in darkness. Seven fungal isolates with the same morphology were obtained using the spore method. The observed colonies were circular, taupe, pewter in color with light gray edging and many cottony aerial mycelia. Conidia were straight, curved or slightly bent, ellipsoidal to fusiform, and septate (typically 4-8 septa per conidium), with the size of 50.0-90.0 μm × 10.0-20.0 μm (n=30). The conidia had a slightly protruding and truncate hilum. These morphological characteristics were consistent with Exserohilum rostratum (Sharma et al., 2014). To further identify the pathogen, isolate WZU-XLH1 was chosen as a representative and the internal transcribed spacer (ITS) and glyceraldehyde-3-phosphate dehydrogenase-like (GAPDH) gene were amplified and sequenced using primer pairs ITS1/ITS4 (White et al., 1990) and Gpd1/Gpd2 (Berbee et al., 1999), respectively. The ITS and gpd gene sequences of isolate WZU-XLH1 were deposited in the GenBank database with accession numbers OQ750113 and OQ714500, respectively. BLASTn analysis showed matches of 568/571 (MH859108) and 547/547 (LT882549) with Exserohilum rostratum CBS 188.68. A neighbor-joining phylogenetic tree was constructed by combining the two sequenced loci, this isolate in the E. rostratum species complex clade at 71% bootstrap support.To verify the pathogenicity of the isolate, ten healthy Broccoli (cultivar 'You Xiu') seedlings with at least five leaves were divided into two groups: one group was inoculated with the isolate, while the other group served as a control. After surface disinfection with 75% ethanol and wiping with sterile water, tiny wounds were made on two leaves (two wounds in one leaf) using an inoculation needle. Fungal culture plugs cut from the isolate were placed on the wounds, while sterile PDA plugs served as the control. The leaves were sealed in wet airtight bags to retain moisture at room temperature with natural light (Cao et al., 2022). After five days, all leaves inoculated with isolate WZU-XLH1 showed symptoms identical to those observed in the field, with no symptoms present in the control group. The pathogenicity was confirmed by repeating the test in triplicate, and fungi re-isolated from symptomatic leaves were identified as E. rostratum by the morphological and molecular methods described above. To the best of our knowledge, this is the first report of E. rostratum causing leaf blight on broccoli in China. This study contributes to our understanding of B. oleracea leaf blight and establishes a basis for future studies on E. rostratum to develop management strategies.

Reduced Daily Light Integral at the End of Production Can Delay Tipburn Incidence with a Yield Penalty in Indoor Lettuce Production

Indoor vertical farms that grow lettuce commonly encounter tipburn, which is an environmental disorder caused by calcium (Ca) deficiency during the late head-forming stages of lettuce. Characterized by marginal leaf necrosis of young expanding leaves, tipburn reduces marketable yield because of the appearance of these necrotic lesions. Lowering the daily light integral (DLI) to slow the plant growth rate has been a widely practiced approach to avoid tipburn in lettuce, but it largely reduces the final yield. We assessed the effect of lowering the DLI only during the end of production, which is a critical time because it is when tipburn is typically observed. Lettuce plants of tipburn-sensitive cultivars Klee and Rex were grown under a tipburn-inducing condition in growth chambers. Sixteen days after transplanting, the DLI was varied to 100% (L100), 85% (L85), 70% (L70), or 55% (L55) of the original 17.4 mol⋅m−2⋅d−1 to grow the final 12 d. At harvest, tipburn severity was reduced by lowering the DLI, but the magnitude of reduction was cultivar-specific. For ‘Klee’, the lowest tipburn severity was found at L55 (8% ± 2.1% of leaves), but the severity was similar for all other DLI levels (33% ± 3.5% of leaves). For ‘Rex’, tipburn severity was highest in the control (L100; 14% ± 2.8% of leaves) but similar for all other DLI levels (2% ± 0.9% of leaves). Reducing the end-of-production DLI to 55% resulted in a linear decrease in yield by up to 22% and 26% for ‘Klee’ and ‘Rex’, respectively. When the increase in marketable yields and decrease in the electricity cost were considered, decreasing the end-of-production DLI yielded a profitable contribution only for ‘Klee’ (L55). For moderately tipburn-sensitive ‘Rex’, revenue losses attributable to the yield decrease were too large to justify this approach of end-of-production reduced DLI.

Comparative morphological analysis reveals a new record of <i>Boehmeria nakashimae</i> (Urticaceae) in Korea

A newly recorded species, <i>Boehmeria nakashimae</i> Yahara, is confirmed for the first time to be distributed on forest edges on Jejudo Island, Korea. This species is known to be endemic to northern Kyushu, Japan. It is characterized by ovate to broadly ovate, ellipticovate, or sub-orbicular middle leaf shapes, serrulate-dentate and uniform margins, 17–29 teeth on one side, a short caudate or narrowly acute apex, dense glomerules at fruiting, and densely strigillose on the stems, both surfaces of the leaves, the perianth of staminate flowers, and achenes. Therefore, it is given the new name ‘Je-ju-top-mo-si-pul’ in Korean based on its serrulate-dentate leaf margin and geographical distribution. A description, photographs, illustrations, and keys of related taxa in Korea are provided.

Mutations in the BoPQL2 gene enhance the sensitivity to low temperature and affect the leaf margin coloration in ornamental kale

Leaf color is an important ornamental trait for ornamental kale. In our previous study, the BoPQL2 gene was identified to exhibit significant differential expression between white and green leaf tissues of ornamental kale. In this study, the gene BoPQL2 was cloned from 'D11′ with white-green variegated inner leaves and '1631′ with fully white inner leaves. Five SNPs were identified between the two above materials, of which four lead to four amino acid substitutions. To elucidate the function of the BoPQL2 gene in ornamental kale, the CRISPR-BoPQL2 vector was constructed and transformed into the 'D11′. Three BoPQL2-deficient mutants were generated, including two homozygous mutants and one double allelic mutant. Compared to the wildtype, the three mutants exhibited full white inner leaves without green margins under the same low temperature condition. These results indicate that the mutations in the BoPQL2 gene increased sensitivity to the low temperature of ornamental kale, thus affecting leaf margin coloration. This study lays the foundation for improving ornamental kale genotypes by editing the BoPQL2 gene.

Character state diversity of Litsea (Lauraceae) leaves in Cianjur Herbarium Hortus Botanicus Tjibodensis

Herbarium serves as a storage place for plants that have been preserved, both in the form of dry and wet preserves. The specimen material is useful in determining the taxonomic status or identity of a plant. Litsea is one of the genera of the Lauraceae tribe (kamper-kamperan) which has similar leaf morphological characters among the species in it or even with other genera that are still in one tribe. The study aims to explain the variation of leaf morphological characters of species of Litsea clan members derived from herbarium specimens of the Cianjur Herbarium Hortus Botanicus Tjibodensis (CHTJ) collection. The research method uses direct observation of specimens in a careful, detailed, high concentration, and still refer to the information data contained in the herbarium sheet. The results showed that the petiole length ranged from 0.7 cm to 3 cm, the petiole surface was hairy (glabrescent) and glabrous. Species of the genus Litsea have leaf shape (circumscriptio): oval (ovalis/ellipticus), elongated (oblongus), and lobed (lanceolatus); The leaf tip (apex folii) is pointed (acutus) in 5 species, and tapered (acuminatus) in 4 species, obtuse (obtusus) in 3 species; the leaf base (base folii) is rounded (rotundatus) in 4 species, obtuse (obtusus) in 5 species, and pointed (acutus) in 3 species; while the arrangement of leaf bones (nervatio or venation) is pinnate (penninervis). The species also have flat leaf margins (margo folii) (integer), with the leaf blade (intervenium) being paper-like and parchment-like, the leaf color is green, and the leaf surface has pilosus.

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 Epicoccum latusicollum causing leaf spot on Lophatherum gracile in Jiangsu Province of China.

Lophatherum gracile Brongn. is an important Chinese herbal medicine. Since 2016, a leaf spot disease has appeared on L. gracile seedlings in the traditional Chinese medicine resource garden of the Institute of Botany, Chinese Academy of Sciences, Jiangsu Province (32.06°N, 118.83°E). About approximately 80% of the seedlings suffered from the disease. The disease spot usually starts from the leaf margin, round or irregular, with yellow halo at the edge of the lesion. To isolate the pathogen, four diseased leaves were collected from four different seedlings and there are 6 sections from each diseased leaf. The leaf sections were surface sterilized in 75% alcohol for 30 s and 1.5% NaClO for 90 s, rinsed three times in sterilized distilled water, plated on potato dextrose agar (PDA). Pure cultures were obtained by monosporic isolation. Eleven isolates were obtained (isolate rate of 55%) and identified as Epicoccum sp.. Thus, a representative isolate, DZY3-3 was used for the further study. After 7 days of culture, the colony produced white aerial hyphae, and reddish orange pigment on the underside. The chlamydospores were produced, either multicellular or unicellular. The colony produced pycnidia and conidia after nearly three weeks of cultivation on oatmeal ager OA. Conidia were unicellular, hyaline, oval, and were 4.9 to 6.4 x 2.0 to 3.3 μm (n=35). In addition, a brown discoloration was produced on malt extract agar (MEA) after using the 1 mol/L NaOH solution for 1 h. These characteristics were consistent with the description of Epicoccum sp. (Chen et al. 2017). To comfirm this identification, the internal transcribed spacer (ITS),large subunit ribosomal RNA (LSU), beta-tubulin (TUB) and RNA polymerase II second largest subunit (RPB2) regions were amplified using the detailed primer pairs described by White et al., Rehner and Samuels, Woudenberg et al. and Liu et al., respectively. They had 99.8-100% homology to the ITS (GenBank no. MN215613, 504/505 bp), LSU (MN533800, 809/809 bp), TUB (MN329871, 333/333 bp), and RPB2 (MG787263, 596/596 bp) sequences of E. latusicollum in the GenBank database. A neighbor-joining phylogenetic tree was generated based on the concatenated sequences of all the above regions in MEGA7. The DZY3-3 clustered in the E. latusicollum clade with 100% bootstrap support. Koch's postulates were performed by spray inoculation (1×106 spores/mL) on the left sides of leaves of three healthy L. gracile seedlings and detached leaves, using isolate DZY3-3, while sterilized water served as the control was sprayed on the right sides of leaves. All plants and detached leaves were covered with clear polyethylene bags to maintain about 80% relative humidity at 25℃. Whether in vivo or in vitro pathogenicity test showed similar symptoms to those occurred in the field after 5 days post inoculation. No symptoms occurred on controls. The experiment was repeated three times. Subsequently, the same fungus was reisolated and identified from leaves of three inoculated seedlings. The E. latusicollum has a very wide host range. For example, it has been reported to cause stalk rot on Maize (Xu et al. 2022) and cause leaf spot on Tobacco in China (Guo et al. 2020). To our knowledge, it is the first report of E. latusicollum causing leaf spot on L. gracile in the world. This study will provide an important reference for the biology of E. latusicollum and the distribution of the disease.

BrrA02.LMI1 Encodes a Homeobox Protein That Affects Leaf Margin Development in Brassica rapa.

Leaf margin morphology is an important quality trait affecting the commodity and environmental adaptability of crops. Brassica rapa is an ideal research material for exploring the molecular mechanisms underlying leaf lobe development. Here, we identified BrrA02.LMI1 to be a promising gene underlying the QTL qBrrLLA02 controlling leaf lobe formation in B. rapa, which was detected in our previous study. Sequence comparison analysis showed that the promoter divergences were the most obvious variations of BrrA02.LMI1 between parental lines. The higher expression level and promoter activity of BrrA02.LMI1 in the lobe-leafed parent indicated that promoter variations of BrrA02.LMI1 were responsible for elevating expression and ultimately causing different allele effects. Histochemical GUS staining indicated that BrrA02.LMI1 is mainly expressed at the leaf margin, with the highest expression at the tip of each lobe. Subcellular localization results showed that BrrA02.LMI1 was in the nucleus. The ectopic expression of BrrA02.LMI1 in A. thaliana resulted in a deep leaf lobe in the wild-type plants, and lobed leaf formation was disturbed in BrrA02.LMI11-downregulated plants. Our findings revealed that BrrA02.LMI1 plays a vital role in regulating the formation of lobed leaves, providing a theoretical basis for the selection and breeding of leaf-shape-diverse varieties of B. rapa.