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Craspedia G.Forst., a genus of tribe Gnaphalieae (Compositae/Asteraceae), is confined to Australia and New Zealand. Twelve species, including Craspedia blepharia Breitw. & Courtney, which we are describing here, are now recognised in New Zealand. Craspedia blepharia is known only from Garibaldi Ridge in Nelson/Tasman, South Island of New Zealand. It is a strong calcicole, confined to exposed, vertical surfaces of limestone cliffs and dolines and quartzose sandstone cliffs which receive calcium-rich seep-water. Its rosettes grow either individually or in dense clumps on cliff faces, thus allowing the plants to receive water from surface water flow. It is distinguished from other New Zealand Craspedia by its rosette leaves clad with a hispid adaxially very dense and abaxially sparse indumentum of very long (2.2–3 mm), usually curved, uniseriate, multiseptate, usually slightly brown or colourless, translucent trichomes that may have a very thin curly, flagellate tip, and leaf margins with a thin white rim formed by the flagellate tips of these long, curved trichomes. We are providing the formal taxonomic treatment together with illustrations and descriptions of its morphology, distribution, habitat, ecology, phenology, and etymology, as well as an assessment of its conservation status. [ABSTRACT FROM AUTHOR]

SUMMARY C4 species have evolved more than 60 times independently from C3 ancestors. This multiple and parallel evolution of the complex C4 trait suggests common underlying evolutionary mechanisms, which could be identified by comparative analysis of closely related C3 and C4 species. Efficient C4 function depends on a distinctive leaf anatomy that is characterised by enlarged, chloroplast‐rich bundle sheath cells and narrow vein spacing. To elucidate the molecular mechanisms that generate the Kranz anatomy, we analysed a developmental series of leaves from the C4 plant Flaveria bidentis and the closely related C3 species Flaveria robusta by comparing anatomies and transcriptomes. Vascular density measurements of all nine leaf developmental stages identified three leaf anatomical zones whose proportions vary with respect to the developmental stage. We then deconvoluted the transcriptome datasets using non‐negative matrix factorisation, which identified four distinct transcriptome patterns in the growing leaves of both species. By integrating the leaf anatomy and transcriptome data, we were able to correlate the different transcriptional profiles with different developmental zones in the leaves. These comparisons revealed an important role for auxin metabolism, in particular auxin homeostasis (conjugation and deconjugation), in establishing the high vein density typical of C4 species. [ABSTRACT FROM AUTHOR]

Pear anthracnose, caused by Colletotrichum bacteria, is a severe infectious disease that significantly impacts the growth, development, and fruit yield of pear trees. Early detection of pear anthracnose before symptoms manifest is of great importance in preventing its spread and minimizing economic losses. This study utilized hyperspectral imaging (HSI) technology to investigate early detection of pear anthracnose through spectral features, vegetation indices (VIs), and texture features (TFs). Healthy and diseased pear leaves aged 1 to 5 days were selected as subjects for capturing hyperspectral images at various stages of health and disease. Characteristic wavelengths (OWs1 and OWs2) were extracted using the Successive Projection Algorithm (SPA) and Competitive Adaptive Reweighted Sampling (CARS) algorithm. Significant VIs were identified using the Random Forest (RF) algorithm, while effective TFs were derived from the Gray Level Co-occurrence Matrix (GLCM). A classification model for pear leaf early anthracnose disease was constructed by integrating different features using three machine learning algorithms: Support Vector Machine (SVM), Extreme Learning Machine (ELM), and Back Propagation Neural Network (BPNN). The results showed that: the classification identification model constructed based on the feature fusion performed better than that of single feature, with the OWs2-VIs-TFs-BPNN model achieving a highest accuracy of 98.61% in detection and identification of pear leaf early anthracnose disease. Additionally, to intuitively and effectively monitor the progression and severity of anthracnose in pear leaves, the visualization of anthracnose lesions was achieved using Successive Maximum Angle Convex Cone (SMACC) and Spectral Information Divergence (SID) techniques. According to our research results, the fusion of multi-source features based on hyperspectral imaging can be a reliable method to detect early asymptomatic infection of pear leaf anthracnose, and provide scientific theoretical support for early warning and prevention of pear leaf diseases. [ABSTRACT FROM AUTHOR]

Leaf pigment content can reflect the nutrient content of the cultivation medium indirectly. To rapidly and accurately predict the pigment content of tomato leaves, chlorophyll a, chlorophyll b, chlorophyll and carotenoid were extracted from the leaves of tomato seedlings cultured at different nitrogen concentrations. The visible/near-infrared hyperspectral imaging non-destructive measurement technology, 430-900 nm and 950-1650 nm, with total variables of 794, was used to obtain the reflection spectra of leaves. An improved strategy of the sparrow search algorithm (SSA) based on logistic chaotic mapping was proposed, and it optimized the back propagation neural network to predict the pigment content of leaves. Different pretreatment methods were used to effectively improve the prediction accuracy of the model. The results showed that when the nitrogen concentration in the nutrient solution was 302.84 mg·L-1, the pigment content of the leaves reached its maximum. Meanwhile, the inhibition effect of high concentrations was much stronger than that of low concentrations. To address the problem that the SSA is prone to premature convergence due to the reduction of population diversity at the end of the iteration, the initialization of the SSA population by logistic chaotic mapping improves the initial solution quality, convergence speed, and search capacity. The root mean squared error (RMSE), coefficient of determination (R2) and relative percent deviation (RPD) of chlorophyll a were 0.77, 0.77, and 2.08, respectively. The RMSE, R2 and RPD of chlorophyll b were 0.30, 0.66, and 1.71, respectively. The RMSE, R2 and RPD of chlorophyll were 0.88, 0.81, and 2.28, respectively. The RMSE, R2 and RPD of carotenoid were 0.14, 0.75, and 2.00, respectively. Hyperspectral imaging technology combined with machine learning algorithms can achieve rapid and accurate prediction of crop physiological information, providing data support for the precise management of fertilization in facility agriculture, which is conducive to improving the quality and output of tomatoes. [ABSTRACT FROM AUTHOR]

Biological shape diversity is often manifested in modulation of organ symmetry and modification of the patterned elaboration of repeated shape elements. 1,2,3,4,5 Whether and how these two aspects of shape determination are coordinately regulated is unclear. 5,6,7 Plant leaves provide an attractive system to investigate this problem, because they often show asymmetries along the proximodistal (PD) axis of their blades, along which they can also produce repeated marginal outgrowths such as serrations or leaflets. 1 One aspect of leaf shape diversity is heteroblasty, where the leaf form in a single genotype is modified with progressive plant age. 8,9,10,11 In Arabidopsis thaliana, a plant with simple leaves, SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 9 (SPL9) controls heteroblasty by activating CyclinD3 expression, thereby sustaining proliferative growth and retarding differentiation in adult leaves. 12,13 However, the precise significance of SPL9 action for leaf symmetry and marginal patterning is unknown. By combining genetics, quantitative shape analyses, and time-lapse imaging, we show that PD symmetry of the leaf blade in A. thaliana decreases in response to an age-dependent SPL9 expression gradient, and that SPL9 action coordinately regulates the distribution and shape of marginal serrations and overall leaf form. Using comparative analyses, we demonstrate that heteroblastic growth reprogramming in Cardamine hirsuta, a complex-leafed relative of A. thaliana, also involves prolonging the duration of cell proliferation and delaying differentiation. We further provide evidence that SPL9 enables species-specific action of homeobox genes that promote leaf complexity. In conclusion, we identified an age-dependent layer of organ PD growth regulation that modulates leaf symmetry and has enabled leaf shape diversification. [Display omitted] • An age-dependent growth gradient underpins regulation of A. thaliana leaf symmetry • SPL9-mediated heteroblastic growth control potentiates leaf histogenic capacity • Common growth patterns underlie heteroblasty in complex and simple leaves • SPL9 enables the action of homeobox genes that promote leaf complexity Li et al. study mechanisms underlying age-dependent changes in leaf symmetry and margin shape. They show that SPL9-mediated regulation of proliferative growth and differentiation along the leaf proximodistal axis modulates organ symmetry and marginal patterning and enables the action of homeobox genes that contributed to complex leaf shape evolution. [ABSTRACT FROM AUTHOR]

Within the circular economy framework, the valorisation of olive leaves as an effective source of organic compounds rather than an agricultural waste, represents a great opportunity. Olive leaves contain bioactive polyphenols, such as the health‐enhancing catechol hydroxytyrosol (HT), derived primarily from oleuropein. This study establishes a novel and sustainable approach for the extraction of HT from olive leaves, utilizing eco‐friendly deep eutectic solvents derived from natural sources (NADES). By optimizing the extraction process, the study highlights the efficacy of the eutectic mixture cholinium/glycerol (1:2 mol/mol) in achieving HT‐rich extracts from olive leaves (0.12 ± 0.03 g HT/g of dry extract). Indeed, the method demonstrates a remarkable yield of HT, reaching 12.3 ± 0.9 g/kg of leaf powder, under optimized conditions. The antioxidant properties of the extract are thoroughly assessed, suggesting its potential health benefits. Significantly, the study underscores the scalability of the extraction method, showcasing its viability for large‐scale production while maintaining excellent outcomes. Furthermore, the sustainability of the extraction method is boosted by the reuse of NADES across multiple extraction cycles, enhancing resource efficiency and reducing environmental impact. This research unlocks the potential of olive leaves as a valuable source of bioactive compounds and outlines a sustainable extraction approach aligning with the principles of the circular economy. [ABSTRACT FROM AUTHOR]

Premise: Increasing aridity in the Mediterranean region affects ecosystems and plant life. Various anatomical changes in plants help them cope with dry conditions. This study focused on anatomical differences in leaves and xylem of five co‐occurring Mediterranean plant species namely Quercus calliprinos, Pistacia palaestina, Pistacia lentiscus, Rhamnus lycioides, and Phillyrea latifolia in wet and dry sites. Methods: Stomatal density, stomatal length, leaf mass area, lamina composition, percentage of intercellular air spaces, and mesophyll cell area in leaves of plants in wet and dry sites were analyzed. Xylem anatomy was assessed through vessel length and area in branches. Results: In the dry site, three species had increased stomatal density and decreased stomatal length. Four species had increased palisade mesophyll and reduced air space volume. In contrast, phenotypic changes in the xylem were less pronounced; vessel length was unaffected by site conditions, but vessel diameter decreased in two species. Intercellular air spaces proved to be the most dynamic anatomical feature. Quercus calliprinos had the most extensive anatomical changes; Rhamnus lycioides had only minor changes. All these changes were observed in comparison to the species in the wet site. Conclusions: This study elucidated variations in anatomical responses in leaves among co‐occurring Mediterranean plant species and identified the most dynamic traits. Understanding these adaptations provides valuable insights into the ability of plants to thrive under changing climate conditions. [ABSTRACT FROM AUTHOR]

Asian (sub)tropical karst regions harbor high endemism and species diversity of sclerophyllous oaks. In this study, Quercus zhekunii, a new species from Guangxi, China, is described and illustrated. Phylogenomic reconstruction using RAD‐seq placed this new species within the ‘Tropical clade' of Quercus sect. Ilex. The dense fused fasciculate and uniserate trichomes on the leaf abaxial surface of Q. zhekunii resemble those of Q. kingiana. However, its distinctively concave primary and lateral veins on the leaf adaxial surface, along with the prominent backward‐recurved leaf blade and leaf margin, make it morphologically distinct from any known species in Q. sect. Ilex. The conservation status of Q. zhekunii is assessed as ‘Endangered' (EN). A new identification key to the species in the ‘Tropical clade' is provided. In addition, character evolution and phylogeography of the ‘Tropical clade' of Q. sect. Ilex is briefly discussed based on the new phylogenetic and morpho‐anatomical data. [ABSTRACT FROM AUTHOR]

The accurate acquisition and prediction of the chlorophyll content in peanuts can provide reference for scientifically sound planting and management of peanut crops. In this study, peanut canopy leaves analysed during the flowering and pegging period were taken as the research object, and the spectral data collected by a portable hyperspectral spectrometer were used as the data source to study the inversion model of peanut leaf soil and plant analyser development (SPAD). To address the issues of randomness, the need for multiple iterations, and strong subjectivity in threshold selection in the initial variable set of the random frog (RF) algorithm, an improved RF algorithm was developed based on the sparse group lasso tool. By analysing and comparing the results of variable extraction of the improved RF algorithm and six characteristic wavelength screening algorithms, three algorithms were selected for pairwise coupling. These six algorithms were the correlation coefficient method (CC), successive projections algorithm, iteratively retains informative variables (IRIV), uninformative variable elimination (UVE), competitive adaptive reweighed sampling, and a genetic algorithm. The results show that: (1) the results of CC, UVE, and IRIV algorithms are better in a single algorithm experiment; and (2) in the coupled algorithms experiment, CC-UVE, CC-IRIV, and UVE-IRIV methods can effectively reduce dimensions, and the model has a certain level of stability. Among them, the UVE-IRIV-Extreme gradient boosting model had the highest accuracy, R2 = 0.652, RMSE = 1.867, and the variable compression rate was as high as 97.84%. The research results can provide a theoretical basis for rapid and accurate monitoring of the SPAD values of peanut leaves. [ABSTRACT FROM AUTHOR]

Festuca makutrensis is an assumed tetraploid species of F. valesiaca agg. described from West Ukraine. However, its current interpretation seems misleading, as it is mostly based on the protologue and opinions of Russian authors, lacking knowledge of the type material and the locus classicus. Here, we collected robust population samples (20–30 plants per population) of known F. makutrensis populations in Ukraine (including locus classicus) and Eastern Poland, along with morphologically similar hexaploids, F. rupicola and F. trachyphylla (65 populations in total). We conducted measurements on 1553 flowering plants to analyze their morphology and examined 4439 leaves in cross section to observe their anatomy. Additionally, we determined ploidy in a selected subset of 61 plants using flow cytometry. Contrary to existing works, our findings unequivocally demonstrate that F. makutrensis is a hexaploid taxon. It closely resembles F. rupicola, with the only distinguishing feature being the ever-present, well-developed additional sclerenchyma strands on the leaf cross section. These strands can occasionally fuse with other strands and form irregular sclerenchyma rings in some (> 25%) plants within the population. The distribution of F. makutrensis appears to be limited to Northwest Podolia and Zhytomyr Polissia in Ukraine, as well as the Lublin Voivodeship in Eastern Poland. Reported occurrences of this taxon outside these regions are considered doubtful. [ABSTRACT FROM AUTHOR]

Xanthium is a genus of annual herbaceous plants that stands out within Asteraceae for being wind‐pollinated, diclinous monoecious, and bearing solitary pistillate flowers in peculiar spiny structures (burs). Xanthium sect. Acanthoxanthium is native to South America and characterized by the presence of trifurcate spines at the base of the leaves. Past taxonomic treatments of the section have been contradictory, some recognising up to six species, others reducing all to a single polymorphic species. Altogether, 42 samples of X. sect. Acanthoxanthium were analysed, the vast majority taken from herbarium specimens between 20 and 160 years old. We sampled multiple specimens of X. spinosum from throughout its broad range as well as those taxa with narrower distributions, covering the whole range of morphological variation in the section. When possible, we included types and original material. We used Hyb‐Seq techniques to obtain information from about 1000 single‐copy nuclear genes and complete plastomes. Phylogenomic data were submitted to coalescent‐based species delimitation approaches (SPEEDEMON). Additionally, we performed geometric morphometric analysis of leaf outlines. The results strongly support the identification of four lineages in the section favouring the acceptance of four of the hitherto described species, i.e., X. ambrosioides, X. argenteum, X. catharticum, and X. spinosum. These results were to some extent corroborated by morphometric analyses. While X. ambrosioides was well distinct from X. spinosum based on leaf morphology, such difference was not observed between X. spinosum and X. catharticum. However, X. catharticum differs from X. spinosum in its ecological requirements, being a species rather adapted to high‐mountain environments of the Neotropics. Intriguingly, X. argenteum – a taxon described from a single herbarium collection – was also inferred as a species. [ABSTRACT FROM AUTHOR]

Quillay (Quillaja saponaria Molina) and peumo (Cryptocarya alba [Molina] Looser) are two tree species endemic to Chile that grow in Mediterranean climate zones, characterized by a summer season with high temperatures, high solar radiation, and low soil water availability. A study was conducted with 2-year-old Q. saponaria and C. alba plants and two substrate water conditions: well-watered and controlled water restriction. At the end of the study, anatomical leaf modifications were analyzed. The tissues were anatomically described in transverse sections of juvenile and adult leaves, measuring leaf thickness, cuticle thickness, and cell density of the mesophyll parenchymal tissues. In the young leaves of Q. saponaria plants undergoing water restriction treatment, an increase in cuticle and leaf thickness and a decrease in the density of the palisade and spongy parenchyma were observed. In contrast, a significant reduction in leaf thickness was observed in adult leaves of both species with water restriction treatment. The anatomical changes in the leaves of Q. saponaria and C. alba suggest an adaptation to adverse environmental conditions, such as water restriction. [ABSTRACT FROM AUTHOR]

Two new species of Vireya Rhododendron, Rhododendron mulyaniae sp. nov. and R. engelbertii sp. nov. were discovered in Tambrauw, Papua, Indonesia. Rhododendron mulyaniae resembles R. angiense in that the scales under the leaf are dendroid, but differs in having elliptic to narrowly elliptic leaves, lacking hairs on petiole, having a tubular funnel shaped corolla. Rhododendron engelbertii resembles to R. carstensense in leaf shape but differs by having narrowly tapering leaf base, scales present on the petiole, and a corolla densely scaly on the outside. Detailed descriptions, illustrations and provisional conservation threat status of these newly described species are provided. [ABSTRACT FROM AUTHOR]

ABSTRACT To avoid reaching lethal temperatures during periods of heat stress, plants may acclimate either their biochemical thermal tolerance or leaf morphological and physiological characteristics to reduce leaf temperature (Tleaf). While plants from warmer environments may have a greater capacity to regulate Tleaf, the extent of intraspecific variation and contribution of provenance is relatively unexplored. We tested whether upland and lowland provenances of four tropical tree species grown in a common garden differed in their thermal safety margins by measuring leaf thermal traits, midday leaf‐to‐air temperature differences (∆Tleaf) and critical leaf temperatures defined by chlorophyll fluorescence (Tcrit). Provenance variation was species‐ and trait‐specific. Higher ∆Tleaf and Tcrit were observed in the lowland provenance for Terminalia microcarpa, and in the upland provenance for Castanospermum australe, with no provenance effects in the other two species. Within‐species covariation of Tcrit and ∆Tleaf led to a convergence of thermal safety margins across provenances. While future studies should expand the number of provenances and species investigated, our findings suggest that lowland and upland provenances may not differ substantially in their vulnerability to heat stress, as determined by thermal safety margins, despite differences in operating temperatures and Tcrit. [ABSTRACT FROM AUTHOR]

The efficiency of CO2 flux in the leaf is hindered by a several structural and biochemical barriers which affect the overall net photosynthesis. However, the dearth of information about the genetic control of these features is limiting our ability for genetic manipulation. We performed a comparative analysis between three-week-old plants of a Mesoamerican and an Andean cultivar of Phaseolus vulgaris at variable light and CO2 levels. The Mesoamerican bean had higher photosynthetic rate, maximum rate of rubisco carboxylase activity and maximum rate of photosynthetic electron transport at light saturation conditions than its Andean counterpart. Leaf anatomy comparison between genotypes showed that the Mesoamerican bean had smaller cell sizes than the Andean bean. Smaller epidermal cells in the Mesoamerican bean resulted in higher stomata density and consequently higher stomatal conductance for water vapor and CO2 than in the Andean bean. Likewise, smaller palisade and spongy mesophyll cells in the Mesoamerican than in the Andean bean increased the cell surface area per unit of volume and consequently increased mesophyll conductance. Finally, smaller cells in the Mesoamerican also increased chlorophyll and protein content per unit of leaf area. In summary, we show that different cell sizes controls the overall net photosynthesis and could be used as a target for genetic manipulation to improve photosynthesis. [ABSTRACT FROM AUTHOR]

Summary Certain species in the Brassicaceae family exhibit high photosynthesis rates, potentially providing a valuable route toward improving agricultural productivity. However, factors contributing to their high photosynthesis rates are still unknown. We compared Hirschfeldia incana, Brassica nigra, Brassica rapa and Arabidopsis thaliana, grown under two contrasting light intensities. Hirschfeldia incana matched B. nigra and B. rapa in achieving very high photosynthesis rates under high growth‐light condition, outperforming A. thaliana. Photosynthesis was relatively more limited by maximum photosynthesis capacity in H. incana and B. rapa and by mesophyll conductance in A. thaliana and B. nigra. Leaf traits such as greater exposed mesophyll specific surface enabled by thicker leaf or high‐density small palisade cells contributed to the variation in mesophyll conductance among the species. The species exhibited contrasting leaf construction strategies and acclimation responses to low light intensity. High‐light plants distributed Chl deeper in leaf tissue, ensuring even distribution of photosynthesis capacity, unlike low‐light plants. Leaf anatomy of H. incana, B. nigra and B. rapa facilitated effective CO2 diffusion, efficient light use and provided ample volume for their high maximum photosynthetic capacity, indicating that a combination of adaptations is required to increase CO2‐assimilation rates in plants. [ABSTRACT FROM AUTHOR]

Polar auxin transport (PAT) is a known component controlling leaf complexity and venation patterns in some model plant species. Evidence indicates that PAT generates auxin converge points (CPs) that in turn lead to local leaf formation and internally into major vein formation. However, the role of PAT in more diverse leaf arrangements and vein patterns is largely unknown. We used the pharmacological inhibition of PAT in developing pinnate tomato, trifoliate clover, palmate lupin, and bipinnate carrot leaves and observed dosage-dependent reduction to simple leaves in these eudicots. Leaf venation patterns changed from craspedodromous (clover, carrot), semi-craspedodromous (tomato), and brochidodromous (lupin) to more parallel patterning with PAT inhibition. The visualization of auxin responses in transgenic tomato plants showed that discrete and separate CPs in control plants were replaced by diffuse convergence areas near the margin. These effects indicate that PAT plays a universal role in the formation of different leaf and vein patterns in eudicot species via a mechanism that depends on the generation as well as the separation of auxin CPs. Computer simulations indicate that variations in PAT can alter the number of CPs, corresponding leaf lobe formation, and the position of major leaf veins along the leaf margin in support of experimental results. [ABSTRACT FROM AUTHOR]

Strawberries are susceptible to various diseases during their growth, and leaves may show signs of diseases as a response. Given that these diseases generate yield loss and compromise the quality of strawberries, timely detection is imperative. To automatically identify diseases in strawberry leaves, a KTD-YOLOv8 model is introduced to enhance both accuracy and speed. The KernelWarehouse convolution is employed to replace the traditional component in the backbone of the YOLOv8 to reduce the computational complexity. In addition, the Triplet Attention mechanism is added to fully extract and fuse multi-scale features. Furthermore, a parameter-sharing diverse branch block (DBB) sharing head is constructed to improve the model's target processing ability at different spatial scales and increase its accuracy without adding too much calculation. The experimental results show that, compared with the original YOLOv8, the proposed KTD-YOLOv8 increases the average accuracy by 2.8% and reduces the floating-point calculation by 38.5%. It provides a new option to guide the intelligent plant monitoring system and precision pesticide spraying system during the growth of strawberry plants. [ABSTRACT FROM AUTHOR]

In this study, the toxicity of the trace element zinc (Zn) in Allium cepa L. test material was examined. Toxicity was investigated in terms of physiological, cytogenetic, biochemical, and anatomical aspects. Germination percentage, root length, weight gain, mitotic index (MI), micronucleus (MN) frequency, chromosomal abnormalities (CAs), malondialdehyde (MDA), proline and chlorophyll levels, superoxide dismutase (SOD) and catalase (CAT) enzyme activities, and meristematic cell damage were used as indicators of toxicity. Additionally, the comet test was used to measure the degree of DNA damage. Four groups of A. cepa bulbs—one for control and three for applications—were created. While the bulbs in the treatment groups were germinated with Zn at concentrations of 35, 70, and 140 mg/L, the bulbs in the control group were germinated with tap water. Germination was carried out at room temperature for 72 h and 144 h. When the allotted time was over, the root tips and leaf samples were collected and prepared for spectrophotometric measurements and macroscopic-microscopic examinations. Consequently, Zn treatment led to significant reductions in physiological indicators such as weight gain, root length, and germination percentage. Zn exposure caused genotoxicity by decreasing the MI ratios and increasing the frequency of MN and CAs (p < 0.05). Zn promoted various types of CAs in root tip cells. The most observed of CAs was the sticky chromosome. Depending on the dose, Zn was found to cause an increase in tail lengths in comet analyses, which led to DNA damage. Exposure to Zn led to a significant decrease in chlorophyll levels and an increase in MDA and proline levels. It also promoted significant increases in SOD and CAT enzyme activities up to 70 mg/L dose and statistically significant decreases at 140 mg/L dose. Additionally, Zn exposure caused different types of anatomical damage. The most severe ones are epidermis and cortex cell damage. Besides, it was found that the Zn dose directly relates to all of the increases and decreases in physiological, cytogenetic, biochemical, and anatomical parameters that were seen as a result of Zn exposure. As a result, it has been determined that the Zn element, which is absolutely necessary in trace amounts for the continuation of the metabolic activities of the organisms, can cause toxicity if it reaches excessive levels. [ABSTRACT FROM AUTHOR]

SUMMARY Hydathodes are small organs found on the leaf margins of vascular plants which release excess xylem sap through a process called guttation. While previous studies have hinted at additional functions of hydathode in metabolite transport or auxin metabolism, experimental support is limited. We conducted comprehensive transcriptomic, metabolomic and physiological analyses of mature Arabidopsis hydathodes. This study identified 1460 genes differentially expressed in hydathodes compared to leaf blades, indicating higher expression of most genes associated with auxin metabolism, metabolite transport, stress response, DNA, RNA or microRNA processes, plant cell wall dynamics and wax metabolism. Notably, we observed differential expression of genes encoding auxin‐related transcriptional regulators, biosynthetic processes, transport and vacuolar storage supported by the measured accumulation of free and conjugated auxin in hydathodes. We also showed that 78% of the total content of 52 xylem metabolites was removed from guttation fluid at hydathodes. We demonstrate that NRT2.1 and PHT1;4 transporters capture nitrate and inorganic phosphate in guttation fluid, respectively, thus limiting the loss of nutrients during this process. Our transcriptomic and metabolomic analyses unveil an organ with its specific physiological and biological identity. [ABSTRACT FROM AUTHOR]

African yam bean (AYB; Sphenostylis stenocarpa) is an underutilized legume indigenous to Africa with great potential to enhance food security and offer nutritional and medicinal opportunities. However, low grain yield caused by fungal diseases, including pod blight and leaf tip dieback, deters farmers from large‐scale cultivation. To determine the prevalence of fungal diseases affecting leaves, pods and flowers of AYB, a survey was conducted in 2018 and 2019 in major AYB‐growing areas in Nigeria. Leaf tip dieback, flower bud rot and pod blight were the most common symptoms. Morphological and molecular assays were conducted to identify the causal agents of the observed diseases. In all the samples examined, fungi from eight genera were isolated from diseased leaves, buds and pods. Koch's postulates were fulfilled only for fungi belonging to the Colletotrichum genus. Fungi from the other seven genera did not produce disease symptoms in healthy AYB tissues. Several Colletotrichum isolates were characterized by sequencing the rDNA internal transcribed spacer (ITS), glyceraldehyde‐3‐phosphate dehydrogenase, calmodulin and ApMAT loci. A combined phylogenetic analysis revealed four Colletotrichum species: C. siamense, C. theobromicola and C. fructicola, which were recovered from diseased leaves, and C. truncatum, recovered from diseased pods and buds. Our results are useful to gear efforts to develop integrated management strategies to control diseases affecting AYB in Nigeria and elsewhere. Availability of such strategies may stimulate greater AYB cultivation, which can contribute to diet diversification, something repeatedly advocated by a range of stakeholders to increase food security and prosperity of smallholder farmers. [ABSTRACT FROM AUTHOR]

Leaves are the largest and more sensitive vegetative organs exposed to external environmental conditions. In order to investigate the effects of habitat aridification on the leaf anatomical structure of wetland plants, Carex moorcroftii leaf plots were set up along the gradient of habitat aridification, and the response of leaf anatomical structure to habitat aridification was analyzed in this study. The results were as follows: (1) The epidermal cells, bulliform cells and air cavity area on the abaxial surface of leaf tip and leaf base, leaf thickness and mechanical tissue thickness at leaf base were significantly positively correlated with soil volumetric moisture content (R²=0.06-0.34, P<0.01); the paraxial cuticle thickness, cell area, number of vascular bundles in parts of leaf tip, leaf middle and leaf base, and diameter of vascular bundle in leaf middle were significantly negatively correlated with soil volumetric moisture content (R²=0.08-0.53, P<0.01) . (2) The anatomical structure of C. moorcroftii leaf had great plasticity (0.53-0.94) and variability (18%-63%), and bulliform cells, air cavities, and paraxial epidermal cells had the greatest plasticity and variability, and the plasticity index and the coefficient of variation of leaf base anatomical structure were significantly higher than that of leaf tip and leaf middle (P<0.05) . When the habitat was aridified, C. moorcroftii leaf adapt to the arid habitat by thickening the cuticle on the paraxial surface, increasing the epidermal cell area, decreasing the air cavity area, and differentiating middle cells, and mainly adopted protective and frugal strategies to adapt to the arid habitat. The results of this study are helpful to reveal the response strategies of C. moorcroftii leaf anatomical structure to arid habitat, and provide theoretical reference for protection and vegetation restoration of alpine meadow. [ABSTRACT FROM AUTHOR]

The classification of Mussaenda L. has been controversial due to the complex interspecific variation and hybridization within the genus. In order to explore the taxonomical significance of leaf venation characteristics between Mussaenda and its relative genera (Schizomussaenda Li and Psudomussaenda Wernham), and to provide data for the identification, development and utilization when they were regarded as the medical and garden plant resources, the leaf venation characteristics of 22 species of this group were observed by using the cleaning method. The cluster analysis was carried out based on the characteristics of leaf venation, and a classification key of the species was compiled. The results were as follows: (1) The characteristics of the leaf venation of Mussaenda and its relative genera had consistency, which were mainly reflected on that the primary veins were all pinnate, the frequency of inter-secondary veins was less than one per areolation, the angles between the major secondary veins and the midveins were acute, the tertiary veins were mostly penetrating, and the arrangement of the areolation were all irregular. (2) The characteristics of the leaf venation with taxonomic value among genera or species within genera included the type of major secondary vein venation type, the angle between major secondary vein and midvein, the major secondary vein spacing, the connection between major secondary vein and midvein, the existence of inter-secondary vein and intramarginal secondary vein, the penetration type of intercostal tertiary vein, the type of quaternary vein, the branching of freely ending veinlet, and the areole development. (3) According to the cluster analysis, 22 species of this group were clustered into 12 branches, and Schizomussaenda and Psudomussaenda were not clustered into one branch respectively, showing a relatively close genetic relationship. In conclusion, the leaf venation characteristics of Mussaenda and its related taxa can provide new information for the classification of the plants. [ABSTRACT FROM AUTHOR]

During taxonomic studies of Evolvulus in the Brazilian northeast, a new species of this genus was discovered in the Brazilian savanna. It is characterized by having prostrate stems, leaf blades that are concolorous and falcate, lanceolate, or narrowly ovate, with leaf bases that are cuneate or rarely rounded. Evolvulus jalapensis sp. nov. is similar to E. anagalloides in sharing prostrate stems, peduncles that do not exceed the leaves, and rotate corollas, but differs from E. anagalloides by leaf blade and base shape, indumentum type, and the distribution of the inflorescences along the branches. A diagnosis, morphological descriptions, illustrations, taxonomic comments, conservation status, distribution map, and an identification key are here provided. [ABSTRACT FROM AUTHOR]

To address the real-time detection challenge of deploying deep learning-based tomato leaf disease detection algorithms on embedded devices, an improved tomato leaf disease detection algorithm based on YOLOv8n is proposed in this paper. It is able to achieve the efficient, real-time detection of tomato leaf diseases while maintaining model's lightweight requirements. The algorithm incorporated the LMSM (lightweight multi-scale module) and ALSA (Attention Lightweight Subsampling Module) to improve the ability to extract lightweight and multi-scale semantic information for the specific characteristics of tomato leaf disease, which include irregular spot size and lush tomato leaves. The head network was redesigned utilizing partial and group convolution along with a parameter-sharing method. Scalable auxiliary bounding box and loss function optimization strategies were introduced to further enhance performance. After undergoing the pruning technique, computation decreased by 61.7%, the model size decreased by 55.6%, and the FPS increased by 44.8%, all while a high level of accuracy was maintained. A detection speed of 19.70FPS on the Jetson Nano was obtained after undergoing TensorRT quantization, showing a 64.85% improvement compared to the initial detection speed. This method met the high real-time performance and small model size requirements for embedded tomato leaf disease detection systems, indirectly reducing the energy consumption of online detection. It provided an effective solution for the online detection of tomato leaf disease. [ABSTRACT FROM AUTHOR]

Kaempferia parviflora, a medicinal plant widely used in Southeast Asia, has been validated clinically for its diverse pharmaceutical applications. Despite extensive research in pharmacology, there is a notable lack of cytogenetic and genomic research, primarily due to limited genetic information. Simple Sequence Repeat (SSR) is considered a robust class of molecular markers frequently used in biodiversity studies. In this study, we adopted Microsatellite Capture Sequencing (MiCAPs) to obtain SSR sequences for marker development. We identified 13,644 SSRs and developed and validated ten sets of SSR markers through capillary electrophoresis. The ten primer sets generated 27 alleles, with an average Polymorphism Information Content (PIC) of 0.36. Principle Coordinate Analysis (PCoA) distinguished two types of K. parviflora, consistent with classification by leaf margin color (red and green). A neighbor-joining dendrogram of seven Zingiberaceae species was constructed with the SSR-containing sequences. The 2-c value of K. parviflora is first reported here as 3.16 ± 0.03; the genome size is estimated at 3090.48 Mbp. The newly developed molecular markers are crucial for variety identification and the conservation of wild resources. Additionally, the cytogenetic and phylogenetic information provides valuable insights into the genetic diversity and evolutionary relationships. [ABSTRACT FROM AUTHOR]

Plants have evolved various photosynthetic adaptations and photoprotective mechanisms to survive in fluctuating and extreme light environments. Many light-activated photosynthetic proteins and enzymes adjust to plant leaf anatomy and leaf pigments to facilitate these processes. Under excessive amounts of light, plants use non-photochemical quenching (NPQ) mechanisms to dissipate excess absorbed light energy as heat to prevent photoinhibition and, therefore, mitigate damage to the plant's photosystems. In this study, we examined photosynthetic adaptations to the light environment in common beans using representative genotypes of the Andean (Calima) and the Mesoamerican (Jamapa) gene pools. We estimated their leaf chlorophyll fluorescence characteristics using dark- and light-adapted mature leaves from three-week-old plants. Our results indicated a higher chlorophyll fluorescence of the light-adapted leaves in the Mesoamerican genotype. NPQ induction was early and extended in the Andean genotype. A similar response in the Mesoamerican counterpart required high light intensity (≥1500 PAR). The NPQ relaxation was rapid in the Mesoamerican genotype (t1/2: 6.76 min) but sluggish in the Andean genotype (t1/2: 9.17 min). These results indicated variable adaptation to light environments between the two common bean genotypes and suggested different strategies for surviving fluctuating light environments that can be exploited for developing plants with environmentally efficient photosynthesis under light limitations. [ABSTRACT FROM AUTHOR]

Some species of the genus Passiflora have leaf morphological adaptations that grow to influence the development of the plant in producing areas. Hence, the objective of this work is to quantify and characterize the leaf anatomy of passion fruit species distributed in the South American region, which can become an important strategy in the selection of species more adapted to the environment where they will be grown. This work evaluates the abaxial and adaxial cuticle thickness (ABCT and ADCT), abaxial and adaxial epidermis thickness (ABET and ADET), xylem diameter (XD), phloem diameter (PD), and thickness of the palisade parenchyma (TPP), of the species Passiflora quadrangularis L., Passiflora foetida L., Passiflora edulis Sims, Passiflora gibertii N.E Brown, Passiflora coccinea Aubl, Passiflora alata Curtis, Passiflora tenuifila Killip, Passiflora caerulea L., and Passiflora cincinnata Mast. Passion fruit species present differences in leaf anatomy, which may influence the plant's development. The species Passiflora quadrangularis L. showed a greater thickness of cuticles, epidermis, conducting vessels, and palisade parenchyma. The species Passiflora edulis has higher density and stomatal functionality. All Passiflora species formed druses on their leaves. [ABSTRACT FROM AUTHOR]

Air-delivered spraying can enhance the effective transport and uniform coverage of fog droplets into the interior of the tree crown. However, it is still unclear on the effect of the intensity of air-delivered flow on the response of a single leaf to the motion state and the microcosmic settlement of fog drop. In this study, a single leaf of a pear tree was placed under the stable air flow in the test section of the wind tunnel equipment. The wind vibration response test was carried out on the leaves of a single pear tree. Four feature points were then marked on the leaves, in order to represent the leaf morphology. Binocular high-speed cameras were used to track the feature points on the leaves. The three-dimensional spatial motion model of simulated leaves was constructed to decompose into several sub-stages for subsequent analysis. A systematic analysis was made on the spatial motion trajectory of feature points, in order to explore the effect of droplet deposition on the leaf surface. The research results were as follows. The leaves showed static stability, swing, and a large number of twisting and turning complex motions under the action of wind-driven air flow. The critical response speed of wind vibration was defined as the generation of a large number of twisting motions. Once the wind speed was lower than the critical airflow speed of wind vibration, the leaves were basically lifted at the angle position in a static and stable state. When the air velocity was greater than or equal to the critical, the dynamic stable state of the leaves was destroyed into a compound motion response state of large spatial swing, turnover, and torsion, indicating the periodic motion state of the leaves under the action of strong air. Specifically, the total travel distances of leaf tips in a space movement period were 180.61, 1140.77, and 766.33 mm, respectively, at the speed of 5, 7, and 9 m/s, and the torsion angles were 290.7°, 896.8°, and 716.2°, respectively. In the test of leaf droplet deposition, the spray droplets were deposited mainly on the side of the leaf facing the airflow direction, when the airflow velocity was lower than 5 m/s. There was also an increase in the airflow velocity. The coverage rate of droplet deposition on the front of the leaf gradually decreased from 43.2% to 10.3%. When the airflow velocity was greater than the critical wind response velocity of 5 m/s, the fog droplets were deposited on both sides of the leaves. However, the droplets were deposited mainly on the opposite side of the leaves with better hydrophilicity. The spatial pose and motion of leaves were also simulated, according to the actual coordinates in the instantaneous position of leaves under the space motion. The finding can further reveal the interaction and deposition between the air flow carrying fog droplets and the leaves in the air-driven sprayer. [ABSTRACT FROM AUTHOR]

Recently, tree species identification has gained in popularity in the silviculture field. As a result, recent works have focussed on recognition of adult evergreen forest trees based on leaves, branching style, bark texture, and, more often, a combination of these features. In this paper, we deal with a new issue: the identification of 2-years-old deciduous fruit-tree varieties within a species, which is a challenging task since we rely exclusively on undistinguishable young bark images. This work is realized to respond to a real need of small farmers interested in planting bare root cultivars. To this purpose, we have built a dataset called AlmBark containing 567 almond bark images with brightness variation and labelled according to the 3 varieties considered (Lauranne, Mazzetto and Independence) which have a high demand in the Tunisian market. We propose a solution combining the Wavelet Transform (WT) technique with a Deep Learning (DL) model for a classification based on almond bark photographs. We investigate the model performances with and without natural background image removal for a mobile implementable solution. Experimentations show that with a background removal step, we obtain an excellent accuracy of 99 % while we obtain a satisfying accuracy of 96.46 % using the original photographs. [ABSTRACT FROM AUTHOR]

Summary: C4 photosynthesis is a complex trait requiring multiple developmental and metabolic alterations. Despite this complexity, it has independently evolved over 60 times. However, our understanding of the transition to C4 is complicated by the fact that variation in photosynthetic type is usually segregated between species that diverged a long time ago.Here, we perform a genome‐wide association study (GWAS) using the grass Alloteropsis semialata, the only known species to have C3, intermediate, and C4 accessions that recently diverged. We aimed to identify genomic regions associated with the strength of the C4 cycle (measured using δ13C), and the development of C4 leaf anatomy.Genomic regions correlated with δ13C include regulators of C4 decarboxylation enzymes (RIPK), nonphotochemical quenching (SOQ1), and the development of Kranz anatomy (SCARECROW‐LIKE). Regions associated with the development of C4 leaf anatomy in the intermediate individuals contain additional leaf anatomy regulators, including those responsible for vein patterning (GSL8) and meristem determinacy (GIF1).The parallel recruitment of paralogous leaf anatomy regulators between A. semialata and other C4 lineages implies the co‐option of these genes is context‐dependent, which likely has implications for the engineering of the C4 trait into C3 species. [ABSTRACT FROM AUTHOR]

C2 photosynthesis is a photosynthetic pathway in which photorespiratory CO2 release and refixation are enhanced in leaf bundle sheath (BS) tissues. The evolution of C2 photosynthesis has been hypothesized to be a major step in the origin of C4 photosynthesis, highlighting the importance of studying C2 evolution. In this study, physiological, anatomical, ultrastructural, and immunohistochemical properties of leaf photosynthetic tissues were investigated in six non‐C4Tribulus species and four C4Tribulus species. At 42°C, T. cristatus exhibited a photosynthetic CO2 compensation point in the absence of respiration (C*) of 21 µmol mol−1, below the C3 mean C* of 73 µmol mol−1. Tribulus astrocarpus had a C* value at 42°C of 55 µmol mol−1, intermediate between the C3 species and the C2T. cristatus. Glycine decarboxylase (GDC) allocation to BS tissues was associated with lower C*. Tribulus cristatus and T. astrocarpus allocated 86% and 30% of their GDC to the BS tissues, respectively, well above the C3 mean of 11%. Tribulus astrocarpus thus exhibits a weaker C2 (termed sub‐C2) phenotype. Increased allocation of mitochondria to the BS and decreased length‐to‐width ratios of BS cells, were present in non‐C4 species, indicating a potential role in C2 and C4 evolution. Summary statement: Physiological, structural, and immunohistochemical analyses of leaf tissues indicate sub‐C2 and C2 character states occurring in Tribulus (Zygophyllaceae). These data reveal novel insights into the mechanisms by which photorespiratory CO2 refixation facilitates the evolution of C4 photosynthesis. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the emergence, early growth, and anatomy of Schinus terebinthifolia Raddi cultivated in iron mining tailings. The seeds were obtained from trees used in urban afforestation and cultivated on two substrates: sand and iron mining tailings. The chemical composition of the mining tailing was characterized. The experiment was conducted in a growth room for 60 days. The emergence rate, seedling survival, height, number of leaves, chlorophyll content, and leaf and root anatomy were evaluated. The analysis of the composition of the mining tailings indicated that macro- and micronutrients were present, as well as potentially toxic elements such as Al, Cd, Cr, and Pb. The mining tailings reduced the emergence rate, and 25% of the seedlings died in this substrate. In addition, the mining tailings promoted a significant reduction in all parameters investigated, including seedling height, number of leaves, chlorophyll content, total leaf thickness, abaxial and adaxial epidermis thickness, palisade parenchyma thickness, and the length and width of the seeds. Additionally, the chloroplasts, the metaxylem vessel diameter, and the phloem proportion were evaluated. Interestingly, the tailings promoted an increase in the secretory channel. In the roots, no significant changes were observed in the parameters analyzed. Thus, the seeds of S. terebinthifolia germinated in the iron mining tailings, and 75% of the seedlings survived, showing their potential for reforestation. Nonetheless, iron mining tailings exhibited toxicity to S. terebinthifolia seedlings, reducing their photosynthetic tissues and, consequently, their growth; this toxicity is likely related to potentially toxic elements present in tailings. [ABSTRACT FROM AUTHOR]

Hybrids between Corylus avellana and Corylusamericana are one of several new perennial and winter annual crops being developed as part of the Forever Green Initiative at the University of Minnesota. As a woody perennial shrub, hazelnuts in agroforestry systems can provide a new revenue source for rural landowners; continuous living cover to prevent soil erosion, sequester soil carbon, protect water quality, and provide wildlife habitat; and a delicious and healthful new local food. If hazelnuts are to fulfill their potential, better germplasm and better nitrogen fertilization recommendations are both needed. We modeled these trials after trials by R.E. Worley, who showed that yields of pecan trees fertilized only when leaf nitrogen (N) fell below critical thresholds were maintained with lower levels of applied N, benefitting both the environment and growers' profits. Results of trials at three Minnesota sites, comparing N applied only when leaf N fell below 1.8%, 2.0%, or 2.2% with annual N applications and no N over 4 years, support using 2.2% leaf N as the critical threshold for N fertilization. Our results showed that whereas only 8% of N applied annually ended up in the harvested nuts and husks, N that was applied to plants that demonstrated hunger for it was more efficiently taken up. Our results suggest a need for more productive germplasm and further research to develop best management practices for N fertilization. [ABSTRACT FROM AUTHOR]

Mangifera indica, a member of the Anacardiaceae family, is an important medicinal plant renowned for its wide range of biological activities. This study aims to examine M. indica from South Africa and describe its key micromorphological features related to foliar structures. Methods employed in this study include stereomicroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) for an in-depth analysis of foliar biology. Additionally, ImageJ software was used to measure the length and diameter values associated with different trichome types on M. indica leaves. The morphological evaluation using stereo- and SEM techniques revealed the presence of non-glandular trichomes with cuticular warts as well as glandular peltate trichomes. TEM micrographs confirmed the presence of numerous mitochondria, starch grains, plastoglobuli, and plastids, providing corroborating evidence of cellular organelles within these cells. Histophytochemical analysis of specific leaf sections further validated that alkaloids and phenolics are the major medicinal compounds obtained through extraction methods. The observations indicated no significant difference between summer and winter seasons concerning common morphology-related characteristics across all categories. The overall findings demonstrate that M. indica's usefulness for compound extractions remains consistent throughout the year due to its similar attributes between seasons. Consequently, continuous cultivation is established as crucial for developing sustainable approaches toward modern medicine. [ABSTRACT FROM AUTHOR]

Prunus (P.) humilis is a small woody shrub that has been widely planted in northern China due to its high nutritional value and resistance to environmental abiotic stress. However, little information about the responses of photosynthetic performance and the anatomical structure of P. humilis to saline–alkaline stress (SAS) under field conditions is available. Here, we investigated the behavior of the photosynthetic apparatus of P. humilis by measuring the chlorophyll fluorescence parameters under moderate (MS) and severe (SS) saline–alkaline stress and analyzing their relationship to leaf anatomical traits. The results showed that SAS significantly decreased the net photosynthetic rate (An) but increased the substomatal CO2 concentration (Ci). The maximum photochemical quantum yield of PSII (Fv/Fm) and the efficient quantum yield of PSII [Y(II)] decreased under MS and SS conditions, and this decrease was greater in the distal (tip) than in the proximal (base) leaf. Compared to the leaf tip, the base of P. humilis leaves seemed to have a stronger ability to cope with MS, as was made evident by the increased quantum yield of regulated energy dissipation in PSII [Y(NPQ)] and decreased excitation pressure (1-qP). Under MS and SS conditions, the shapes of the chlorophyll a fluorescence transient (OJIP) changed markedly, accompanied by decreased PSII acceptor-side and donor-side activities. The palisade–spongy tissue ratio (PT/ST) increased significantly with increasing stress and showed a significant correlation with the chlorophyll fluorescence parameters in the leaf base. These results suggested that the activity of PSII electron transfer in the upper leaf position tended to be more sensitive to saline–alkaline stress, and a chlorophyll fluorescence analysis proved to be a good technique to monitor impacts of saline–alkaline stress on photosynthetic function, which may reflect the non-uniformity of leaf anatomy. In addition, among the anatomical structure parameters, the palisade–spongy tissue ratio (PT/ST) can be used as a sensitive indicator to reflect the non-uniform of photosynthetic function and leaf anatomy under stress. [ABSTRACT FROM AUTHOR]

AbstractForestiera includes woody plants distributed from the United States to Ecuador, with a wide distribution in Mexico. However, basic knowledge about its biology and taxonomy is still limited. In the present study, a leaf morphometric analysis of the 14 Mexican Forestiera species, including F. neomexicana, was carried out to determine if leaf characters allow classifying the species and to evaluate if the inclusion of qualitative features in statistical analyses improves the fit of used methods. Four quantitative and four qualitative variables from herbarium specimens, were evaluated. A matrix was generated which was submitted to multivariate analysis, including Linear Discriminant Analysis and Random Forest. Results revealed that the species are correctly classified, with Random Forest being the method with the best classifying capacity. The most important variables to differentiate the species are the shape of the base, width and margin of the leaves. All species were classified as different entities including F. pubescens and F. neomexicana, currently considered synonyms, were classified by Random Forest as different entities. [ABSTRACT FROM AUTHOR]

Premise Methods Results Conclusions Up to half of tropical forest plant species grow on other plants. Lacking access to soils, vascular epiphytes have unique adaptations for mineral nutrition. Among the most distinctive is the tank growth form of certain large bromeliads, which absorb nutrients that are cycled by complex microbial communities in water trapped among their overlapping leaf bases. However, tanks form only after years of growth by juvenile plants, which must acquire nutrients differently. Understanding how nutrient dynamics change during tank bromeliad development can provide key insights into the role of microorganisms in the maintenance of tropical forest biodiversity.We evaluated variations in plant morphology, growth, foliar nitrogen physiology, and phyllosphere bacterial communities along a size gradient spanning the transition to tank formation in the threatened species Tillandsia utriculata.Sequential morphological and growth phases coincided with the transition to tank formation when the longest leaf on plants was between 14 and 19 cm. Before this point, foliar ammonium concentrations were very high, but after, leaf segments absorbed significantly more nitrate. Leaf‐surface bacterial communities tracked ontogenetic changes in plant morphology and nitrogen metabolism, with less‐diverse communities in tankless plants distinguished by a high proportion of taxa implicated in ureolysis, nitrogen fixation, and methanotrophy, whereas nitrate reduction characterized communities on individuals that could form a tank.Coupled changes in plant morphology, physiology, and microbiome function facilitate the transition between alternative nutritional modes in tank bromeliads. Comparing bromeliads across life stages and habitats may illuminate how nitrogen‐use varies across scales. [ABSTRACT FROM AUTHOR]

Mesophyll conductance (gm ${g}_{{\rm{m}}}$) describes the efficiency with which CO2 ${\mathrm{CO}}_{2}$ moves from substomatal cavities to chloroplasts. Despite the stipulated importance of leaf architecture in affecting gm ${g}_{{\rm{m}}}$, there remains a considerable ambiguity about how and whether leaf anatomy influences gm ${g}_{{\rm{m}}}$. Here, we employed nonlinear machine‐learning models to assess the relationship between 10 leaf architecture traits and gm ${g}_{{\rm{m}}}$. These models used leaf architecture traits as predictors and achieved excellent predictability of gm ${g}_{{\rm{m}}}$. Dissection of the importance of leaf architecture traits in the models indicated that cell wall thickness and chloroplast area exposed to internal airspace have a large impact on interspecific variation in gm ${g}_{{\rm{m}}}$. Additionally, other leaf architecture traits, such as leaf thickness, leaf density and chloroplast thickness, emerged as important predictors of gm ${g}_{{\rm{m}}}$. We also found significant differences in the predictability between models trained on different plant functional types. Therefore, by moving beyond simple linear and exponential models, our analyses demonstrated that a larger suite of leaf architecture traits drive differences in gm ${g}_{{\rm{m}}}$ than has been previously acknowledged. These findings pave the way for modulating gm ${g}_{{\rm{m}}}$ by strategies that modify its leaf architecture determinants. [ABSTRACT FROM AUTHOR]

Andean ecosystems are characterized by high humidity, mainly from rain and fog events. Because of differences in altitude two Andean ecosystems – sub‐Andean forest and Páramo –face different environmental pressures that affect leaf anatomy and cell wall composition and, consequently, species foliar water uptake (FWU) capacity. Here, FWU capacity of eight species in the Melastomataceae was evaluated and found to be related to proportions of cell wall components and aquaporins in the two ecosystems. Cellulose was labelled with Calcofluor white, and aquaporin and pectins were labelled with monoclonal antibodies. There were differences in plant FWU capacity in both ecosystems, with higher FWU capacity in sub‐Andean forest species than in Páramo forest species. Cell wall components were positively related to FWU, with increased FWU related to pectin and aquaporin content of the plasma membrane. Differences in water availability in the two analysed environments led to differences in FWU capacity that are associated with leaf anatomical traits and cell wall composition. In these two environments, plants with similar traits are selected to respond to given environmental pressures. Traits that favour FWU in sub‐Andean forest species may lead to further advances of these species in this environments. [ABSTRACT FROM AUTHOR]

The use of exotic grasses of African origin for pastures in Brazil has been a major advancement in livestock production, but little is known about the responses of these grasses to nitrogen fertilizers associated with shading. In this study, the morphogenetic, structural, and leaf anatomical characteristics of Megathyrsus maximus cultivars' Tamani and Quênia were investigated as a function of N dose and shade. Morphogenetic and structural characteristics and leaf anatomy were studied under three shading levels (0, 30, and 50 %) and four N doses (0, 100, 200, and 300 kg N ha-1) to simulate growth in a silvopastoral system. When comparing the cultivars, Quênia was more efficient in terms of phyllochron up to fertilization with 100 kg N ha-1. The leaf senescence rate of Tamani was higher than that of Quênia at the 30 and 50 % shade levels. The total area (TA) occupied by leaf tissues decreased in Quênia as a function of the increase in N fertilization, whereas the TA of Tamani did not change. The thickness of the adaxial epidermis was greater in Quênia (0.68 µm) than in Tamani (0.50 µm) when not fertilized. The area occupied by the mesophyll was greater in both cultivars when they received fertilization equivalent to 300 kg N ha-1. Quênia grass has a smaller phyllochron than Tamani grass, due to the rapid reconstruction of its photosynthetic apparatus, especially when it receives higher levels of nitrogen fertilization. However, Tamani grass has a greater distribution of plant tissues. The mesophyll area is larger in Tamani grass due to the greater presence of chloroplasts, which facilitates digestion by animals. The Tamani modified the leaf anatomical tissues more significantly in relation to shading, whereas the Quênia modified them in relation to N fertilization, which reinforces the suggestion of a more appropriate use of Tamani in silvopastoral systems. [ABSTRACT FROM AUTHOR]

Dendrobium officinale soft rot is a widespread and destructive disease caused by Fwarium oxy.porum that can seriously affect yield and quality. To better understand the fungal infection and colonization, we successfully created an E Oxysporum labeled with green fluorescent protein using the Agrobacterium tumefaciens-mediated transformation method. Transformants had varying fluorescence intensities, but their pathogenicity did not differ from that of the wild type. Fluorescence microscopy revealed that E oxysportim primarily entered the aboveground portion of D. offlcinale through the leaf margin, stomata, or by direct penetration of the leaf surface. It then colonized the mesophyll and spread along its vascular bundles. D. officinale exhibited typical symptoms of decay and wilting 14 days postinoculation, accompanied by a pronounced fluorescence signal in the affected area. The initial colonization of E OX);Sp in the subterranean region primarily involved attachment to the root hair and epidermis, which progressed to the medullary vascular bundle. At 14 days postinoculation, the root vascular bundles of D. officinale exhibited significant colonization by E oxysporum. Macroconidia were also observed in black rot D. officincile tissue. In particular, the entire root was surrounded by a significant number of chlamydospore-producing F. oxysporum mycelia at 28 days postinoculation. This approach allowed for the visualization of the complete infection process of E oxysporum and provided a theoretical foundation for the development of field control strategies. [ABSTRACT FROM AUTHOR]

Phalaenopsis is one of the most popular orchid genera, exhibiting a variety of flower morphologies. Ploidy level was a factor influencing the success of Phalaenopsis crossbreeding. This research aimed to determine the ploidy level by flow cytometry and correlation with morphological characteristics on six hybrid cultivars of Phalaenopsis (1702, 1819, 1981, 3903, 3904, and 3908). Flow cytometry analysis on young leaves and root tip cells was also carried out on P. amabilis, P. amboinensis, and P. schilleriana. Research results showed multiple peaks of fluorescence appeared on the flow cytometry histogram. The young leaves and root tip cells show the distribution of cells into different ploidy levels and indicate mixoploid and endopolyploid conditions of the cells in both leaves and root samples. This complexity makes it challenging to determine the ploidy level of each cultivar and the correlation between morphological characteristics and ploidy level, even though the weak positive correlation was prominent between flower numbers and genome size. These findings serve as foundational data on the cytogenetic background of the cultivars for orchid breeders in crossbreeding, selection of haploid plants, mutation analysis, and variety consistency monitoring. [ABSTRACT FROM AUTHOR]

Mesophyll resistance for CO2 diffusion (rm) is one of the main limitations for photosynthesis and plant growth. Breeding new varieties with lower rm requires knowledge of its distinct components.We tested new method for estimating the relative drawdowns of CO2 concentration (c) across hypostomatous leaves of Fagus sylvatica. This technique yields values of the ratio of the internal CO2 concentrations at the adaxial and abaxial leaf side, cd/cb, the drawdown in the intercellular air space (IAS), and intracellular drawdown between IAS and chloroplast stroma, cc/cbd. The method is based on carbon isotope composition of leaf dry matter and epicuticular wax isolated from upper and lower leaf sides. We investigated leaves from tree‐canopy profile to analyse the effects of light and leaf anatomy on the drawdowns and partitioning of rm into its inter‐ (rIAS) and intracellular (rliq) components. Validity of the new method was tested by independent measurements of rm using conventional isotopic and gas exchange techniques.73% of investigated leaves had adaxial epicuticular wax enriched in 13C compared to abaxial wax (by 0.50‰ on average), yielding 0.98 and 0.70 for average of cd/cb and cc/cbd, respectively. The rIAS to rliq proportion were 5.5:94.5% in sun‐exposed and 14.8:85.2% in shaded leaves. cc dropped to less than half of the atmospheric value in the sunlit and to about two‐thirds of it in shaded leaves.This method shows that rIAS is minor but not negligible part of rm and reflects leaf anatomy traits, i.e. leaf mass per area and thickness. [ABSTRACT FROM AUTHOR]

Hyperspectral remote sensing combined with data preprocessing techniques and machine learning algorithms is a new way to efficiently estimate plant SPAD. In this study, the raw hyperspectral reflectance data of the dwarf forest of Cinnamomum camphora (Linn.) Presl (C. camphora) were subjected to 0-2nd order differential transformations (a step size of 0.25) using SPAD during the harvesting period of C. camphora. The spectral indices with the highest correlation with SPAD in each order were also selected as input variables for the model, and the measured values of SPAD from simultaneous observations were used as the output variable. Support vector machine (SVM), random forest (RF), and backpropagation neural network (BPNN) were used to construct the SPAD inversion model. The results showed that the correlation between the spectral index and the SPAD of the dwarf forest of C. camphora and the accuracy of the constructed prediction model tended to increase and then decrease with increasing differential order. After a comprehensive comparison, the RF-based SPAD prediction model achieved the highest accuracy with a coefficient of determination (R2) of 0.824, root mean square error (RMSE) of 1.619, and mean relative error (MRE) of 3.207% for the validation set, using spectral indices computed by the 1.5-order differential treatment as the input variables. This study provides a theoretical basis for improving the accuracy of plant leaf SPAD inversion based on hyperspectral remote sensing. [ABSTRACT FROM AUTHOR]

It aimed to estimate the forage intake by lambs managed in different leaf allowances on Brachiaria-grass using internal and external markers. Forty-eight Texel lambs with 17.52 ± 3.48 kg were evaluated which were 12 testers and 36 regulators. The lambs were kept in twelve paddocks, subdivided into four treatments based on green leaf allowance (60, 75, 90, and 105 g/kg of BW). The experimental design was completely randomised. To estimate dry matter intake (DMI), the following markers were used: indigestible dry matter (iDM); indigestible neutral detergent fibre (iNDF); indigestible acid detergent fibre (iADF); lignin in indigestible acid detergent (iADL) and titanium dioxide (TiO2). Comparisons between intake markers were made using Chromic Oxide (Cr2O3) as a control marker. The leaves allowance tested did not alter the voluntary intake by lambs kept in Brachiaria-grass pasture. Comparison between the control intake marker (Cr2O3) and the other markers by Dunnett's test showed that, regardless of green leaf allowance, the Cr2O3, TiO2 and iADL markers provided similar estimates of DMI, but with lower values than the other markers. External marker TiO2 and the internal iADL were demonstrated to be more suitable for estimating the dry matter intake in grazing lambs regardless of the leaf allowance. [ABSTRACT FROM AUTHOR]

The Crocus gargaricus complex (Iridaceae) is known from a handful of scattered populations and three taxa from Turkey. The relationship between these taxa and their taxonomic state, however, has remained controversial for the past 200 years. Crocus gargaricus was described from Mount Ida in 1841 and later a geographically distant population was discovered at Göktepe, Muğla. The closely related C. thirkeanus, which was considered a synonym for about 40 years until 1984 when it was elevated to subspecies level as C. gargaricus subsp. herbertii, was known only from Uludağ. The latest molecular methods have now shown C. thirkeanus and C. gargaricus to be distinct species. However, one major limitation of previous studies was their heavy reliance on cultivated material. This study examines all known populations of the C. gargaricus complex, collected from their type locations, as well as two more recently discovered populations (Kütahya and İzmir). We combine morpho-anatomical measurements, statistical data analyses and molecular phylogeny to help resolve the relationships between these taxa across their known ranges. Our analysis revealed a clear division of the six populations into three taxa: C. gargaricus, C. thirkeanus and C. cigdemiae, a new species described herein. [ABSTRACT FROM AUTHOR]

This study examines the growth patterns, leaf morpho-anatomical traits and physiological characteristics of three ornamental taxa of Alocasia: A. melo, A reginae and Alocasia × morfontanensis 'Bambino'. Using optical and scanning electron microscopy, the research obtained anatomical details of the leaves. Alocasia × morfontanensis 'Bambino' exhibited the highest leaf growth rate among the taxa studied, showing significant leaf number increases from the 8th to the 12th week after planting. Alocasia melo produced 2–3 new basal shoots after 20 weeks, whereas the other two taxa did not produce any. Alocasia melo displayed the greatest relative water content and leaf thickness, while A. reginae showed the highest chlorophyll stability. This study also revealed variations in the adaxial and abaxial leaf color, stomatal width, epidermal thickness, and elemental composition among the taxa involved, with A. melo containing rhodium and high levels of calcium on their leaf surface. These findings contribute to the understanding of the Alocasia leaf morpho-anatomy and growth, which is useful for optimizing Alocasia cultivation and production across diverse ecosystems. [ABSTRACT FROM AUTHOR]

Among the plethora of diseases which impede wheat productivity, spot blotch has emerged as a major contributor to economic yield loss in wheat. The identification and development of resistant varieties is the most effective strategy for disease management. However, the use of partial resistance components for phenotyping of disease resistance is a suitable alternative as compared to conventional phenotyping, owing to its conspicuous nature. Thus, six traits, viz., Leaf tip necrosis (LTN), Lesion mimic (LM), Leaf Angle (LA), Lesion size (LS), Lesion type (LT) and Area Under SPAD Value Decline Curve (AUSDC), were studied in 50 wheat genotypes to assess their influence on spot blotch of wheat. The study revealed significant differences in the expression of the traits across the genotypes evaluated. The genotypes with lower Area Under Disease Progress Curve (AUDPC) recorded higher LTN, and AUSDC, while lower values were recorded for LM, LS, LA and LT. A significant positive correlation was observed between AUDPC and LM (r2 = 0.72), LT (r2 = 0.81), LA (r2 = 0.84) and LS (r2 = 0.97), while a negative correlation was recorded between AUDPC with LTN (r2= −0.46) and AUSDC (r2= −0.87). A negative correlation was also observed between lesion mimic and leaf tip necrosis (r2= −0.53), indicating the inhibitory effect of the traits on each other. Principal component analysis extracted two main components, which explained the results most appropriately. The traits which were identified as inhibitory towards spot blotch disease development may be studied further against other pathogens of wheat. [ABSTRACT FROM AUTHOR]

Accurately detecting tea bud leaves is crucial for the automation of tea picking robots. However, challenges arise due to tea stem occlusion and overlapping of buds and leaves, presenting varied shapes of one bud–one leaf targets in the field of view, making precise segmentation of tea bud leaves challenging. To improve the segmentation accuracy of one bud–one leaf targets with different shapes and fine granularity, this study proposes a novel semantic segmentation model for tea bud leaves. The method designs a hierarchical Transformer block based on a self-attention mechanism in the encoding network, which is beneficial for capturing long-range dependencies between features and enhancing the representation of common features. Then, a multi-path feature aggregation module is designed to effectively merge the feature outputs of encoder blocks with decoder outputs, thereby alleviating the loss of fine-grained features caused by downsampling. Furthermore, a refined polarized attention mechanism is employed after the aggregation module to perform polarized filtering on features in channel and spatial dimensions, enhancing the output of fine-grained features. The experimental results demonstrate that the proposed Unet-Enhanced model achieves segmentation performance well on one bud–one leaf targets with different shapes, with a mean intersection over union (mIoU) of 91.18% and a mean pixel accuracy (mPA) of 95.10%. The semantic segmentation network can accurately segment tea bud leaves, providing a decision-making basis for the spatial positioning of tea picking robots. [ABSTRACT FROM AUTHOR]