Stomatal Research Articles

Screening Smoke Tree (Cotinus coggygria Scop.) on Osmotic Stress using Polyethylene Glycol 6000 in vitro

Background: Droughts during the growing season are becoming increasingly common due to climate change and global warming. The study’s goal study was to assess the adaptation mechanisms of C. coggygria Scop. under simulated water deficit conditions using indicators characterized changes in the leaf stomatal apparatus and photosynthesizing system. Methods: The influence of osmotic polyethylene glycol 6000 on the research object C. coggygria regenerants was studied in vitro. Such indicators as morphological changes, pigment content, stomatal density and size and stomatal slit size were quantified. Result: Due to the influence of osmotic stress, there was a pigment content increase in the leaf plate on osmotic media. Stomatal density raised by 27.0-29.8% in explant cells cultivated on PEG 4.0-6.0%. Under the osmotic influence, there was a drop in the stomatal cells’ area and shape and the ratio of stomatal length to width in the regenerant leaves decreased from 1.5 to 1.0-1.1. These results indicate the adaptation of C. coggygria regenerants to stress caused by an artificial drought in vitro. The changes’ identification in the stomatal apparatus and the C. coggygria pigment ratio will accelerate the selective screening of drought-resistant plants for use in protective forestry.Background: Droughts during the growing season are becoming increasingly common due to climate change and global warming. The study’s goal study was to assess the adaptation mechanisms of C. coggygria Scop. under simulated water deficit conditions using indicators characterized changes in the leaf stomatal apparatus and photosynthesizing system.

Creation and characteristics of tetraploid and mixoploid centipedegrass

AbstractPloidy manipulation has been used in many crop improvement programs to develop plant species with wider adaptability and desirable traits. The objectives of this study were to create stable tetraploid centipedegrass (Eremochloa ophiuroides [Munro] Hack.) lines and evaluate them for beneficial traits. To generate polyploid lines, “TifBlair” (2n = 2x = 18) seeds were exposed to gamma radiation and callus was generated using tissue culture, exposed to glyphosate and regenerated into plantlets. After 5 years of continuous propagation, two lines, Hongliang Wang (HW)16 and HW123, were found to be tetraploid, and one line, HW61, was found to be a mixoploid using flow cytometry and chromosome counts. Nuclear DNA contents for diploid and tetraploid lines ranged from 1.97 to 2.10 and 4.14 to 4.30 pg 2C−1, respectively. Ten centipedegrass lines were genotyped using seven simple sequence repeat markers and clustered by origin (derived from TifBlair or the University of Georgia breeding program). Six lines were evaluated for morphological and physiological traits under greenhouse conditions. Trait evaluation showed that tetraploid lines had larger stomata and leaf width and reduced stomatal density. For all other traits evaluated under greenhouse conditions, although significant differences were observed between lines, no consistent differences separated diploid and tetraploid lines. Between the tetraploid lines, HW16 had higher evapotranspiration, percentage green cover, and relative water content than HW123, whereas HW123 had a higher average clipping yield and root width than HW16. In conclusion, irradiation and tissue culture are valuable techniques for the generation of stable polyploid lines, and an increased ploidy level led to larger vegetative structures in centipedegrass.

Seed treatment with chlormequat chloride improves the physiological and biochemical characteristics of Brassica napus L. under salt stress

BackgroundSalinity is a global and increasing problem in agriculture. The response of Brassica napus L. (canola or oilseed rape) to salinity and the possible role of chlormequat chloride (CCC) as a seed primer in improving salt tolerance were investigated in a pot experiment. The experiment consisted of four salinities (0, 0.5, 1 and 1.5 g NaCl kg−1 soil) and four CCC concentrations (0, 250, 500 and 750 mg L − 1) in a complete randomised block design with three replications. ResultsSalt stress decreased relative water content (RWC), stomatal conductance, stomatal density, photosynthetic rate, chlorophyll, potassium and calcium content, K/Na, Ca/Na ratio and seed yield, but increased leaf temperature, intercellular CO2 concentration, proline, electrolyte leakage, stomatal area and sodium content. Application of CCC, especially 500 and 750 mg L − 1, improved all measured traits and Ca and K contents. The increase in K and Ca content and the simultaneous decrease in Na content indicate improved ion selectivity in plants treated with CCC. Stomatal density was reduced by salt stress, while higher concentrations of CCC increased the number of stomata, especially in the abaxial part, thus reducing the adaxial/abaxial stomatal number ratio. Reduced stomatal number due to salt stress increased the resistance of canola to salt stress by preventing transpiration rate and can be considered as a stress avoidance and water saving mechanism in canola. There is no significant difference in all measured traits between non-saline and mild saline stress, but seed yield decreased at this stress level compared to the control condition. ConclusionThe results suggest that the application of CCC increased the photosynthetic, physiological, and biochemical attributes and seed yield of canola plants. The data show that 500 and 750 mg CCC L − 1 in saline soils up to 10.5 dS m − 1 can improve yield and physiological parameters of canola.

In Vitro Conservation and Regeneration of Potato (Solanum tuberosum L.): Role of Paclobutrazol and Silver Nanoparticles

In vitro conservation and regeneration of potato germplasm is important in breeding programs. The objective of this study was to assess the combined effect of paclobutrazol (PAC) and silver nanoparticles (AgNPs) during reduced-growth conservation and their in vitro ability to regenerate S. tuberosum after conservation treatments. For the conservation system, apices were used as explants in Murashige and Skoog culture media with different combinations of PAC (0, 0.5, 1 and 2 mg L−1) and AgNPs (0, 50, 100 and 200 mg L−1). At six months of culture, plant length, number of lateral branches, number of leaves and roots, root length, stomatal density and total chlorophyll content were assessed. For regeneration, explants were internodes cultured in medium with only 2 mg L−1 benzyladenine (BA). At 60 d of culture, the response percentage, number of shoots per explant and shoot length were assessed. For in vitro conservation, the combination of 2 mg L−1 PAC and 50 mg L−1 AgNPs was the best treatment, whereas for in vitro regeneration, the highest number of shoots was in explants that were treated with 1 or 2 mg L−1 PAC with 50 mg L−1 AgNPs. In conclusion, PAC and AgNPs are alternatives for in vitro S. tuberosum conservation, and their evaluation in other species recalcitrant to the effect of ethylene is recommended.

Evaluation the Urban Atmospheric Conditions Using Micronuclei Assay and Stomatal Index in Tradescantia pallida

Air pollution substantially damages ecosystems and public health and is one of the major challenges for air quality monitoring management. The use of the plant bioindicator Tradescantia pallida (Rose) D. R. Hunt has shown excellent results in terms of determining the effect of airborne contaminants in urban environments, complementing conventional methods. The present study seeks to determine the air quality in the Ivinhema Valley, MS, using the variation in MCN frequency and stomatal indices of T. pallida as air pollution biomarkers. The biomonitoring tests were performed monthly by collecting floral and leaf buds during the summer, autumn, winter, and spring of 2021 in Angélica, Ivinhema, and Nova Andradina. The stomatal leaf density, influence of vehicle flow, and environmental variables such as altitude, temperature (°C), relative humidity (RH), and rainfall in the three cities under study with different urban vehicle intensities were analyzed. A significant increase in MCN was observed for the cities of Nova Andradina and Ivinhema in summer and spring. On the other hand, the city of Angélica had a low frequency of MCN throughout the experimental period. A seasonal and spatial pattern was also observed for the stomatal index, with significantly higher values for the city of Angélica in autumn and winter. Our data allowed observing that the MCN showed the greatest association with vehicular flow. The mutagenic effects observed in T. pallida, through the MCN frequency, constituted an important biomarker of air pollution, explained mainly by the relationship with the flow of vehicles.

Low fertilization optimizes the water use efficiency of an Amazonian canga grass for mineland rehabilitation

ABSTRACT The peculiar characteristics of mining waste substrates represent a significant challenge for environmental rehabilitation. Here, we evaluated the revegetation potential of Paspalum cinerascens on substrates from mining areas of Serra dos Carajás, a region harboring a large mine complex in the eastern Brazilian Amazon. Paspalum cinerascens is a native grass widely distributed in the canga ecosystem, a vegetation type covering iron ore reserves. Seeds of P. cinerascens harvested in canga were germinated in sterilized quartzite sand and the seedlings grown in controlled conditions for 90 days. The seedlings were then cultivated in canga topsoil (control, without fertilization) and mining waste substrate with half and complete fertilization currently applied at the beginning of mineland rehabilitation in Serra dos Carajás. Regardless of fertilization, plants grown in the mining waste substrate did not differ in carbon assimilation, tillering rate and root biomass, despite higher leaf nutrient content and lower root: shoot ratio when compared to plants in canga topsoil. Compared to the control, complete fertilization led to significantly taller plants, higher shoot biomass and reduced water use efficiency. Half fertilization led to higher phosphorus and water use efficiency and stomatal density. Our results confirmed that P. cinerascens has adaptive traits to grow and thrive in the harsh environmental conditions of post iron ore mining, and can be used in rehabilitation processes. Moreover, half fertilization led to plants with optimized water loss in exchange for carbon without significant costs to plant growth, an interesting trait for rehabilitation in areas experiencing water restrictions.

Plant Growth and Root Morphology Are Affected by Earthworm-Driven (Eisenia sp.) Changes in Soil Chemico-Physical Properties: a Mesocosm Experiment with Broccoli and Faba Bean

Earthworms are “ecosystem engineers” that improve soil water and nutrient content, soil macroporosity, and aeration, and provide suitable habitats for microbial populations. This study aimed at defining if the presence of epigeic earthworms (Eisenia sp.) affected the growth and development of two plant species (Brassica oleracea and Vicia faba) via the modifications of soil chemico-physical properties. A mesocosm experiment, in which plants were grown outdoors for 4 months with or without earthworms, was performed. The two plant species were selected based on their different habitus and root architecture and morphology. Soil macroporosity (Msoil) and water holding capacity (WHCsoil) were determined. Earthworm-driven bioturbation (Bsoil) was measured by filling mesh bags with artificial soil. Earthworm abundance and biomass, together with plant morphometric parameters (root and leaf morphology by imaging and microscope techniques), were measured at the end of the trial. The presence of earthworms increased Msoil (on average +16%) and WHCsoil (on average +9%) and this was accompanied by a remarkable degree of Bsoil. In most of the cases, earthworms enhanced plant growth in the two plant species studied, with a significant positive influence on the majority of the shoot and root traits. A significant increase of stomatal density (on average +24%) occurred in the leaves of both the plant species in the presence of earthworms. Our results confirmed the hypothesis that bioturbation by Eisenia sp. had a significant positive effect on plant growth, independently from the plant species cultivated, and that these growth-promoting effects were mediated by changes in soil chemico-physical parameters. By taking into account the essential role of earthworms in maintaining healthy soils and the vegetation they support, soils can become more resilient against environmental perturbations and climate change.

Role of NPR1 in Systemic Acquired Stomatal Immunity.

Stomatal immunity is the primary gate of the plant pathogen defense system. Non-expressor of Pathogenesis Related 1 (NPR1) is the salicylic acid (SA) receptor, which is critical for stomatal defense. SA induces stomatal closure, but the specific role of NPR1 in guard cells and its contribution to systemic acquired resistance (SAR) remain largely unknown. In this study, we compared the response to pathogen attack in wild-type Arabidopsis and the npr1-1 knockout mutant in terms of stomatal movement and proteomic changes. We found that NPR1 does not regulate stomatal density, but the npr1-1 mutant failed to close stomata when under pathogen attack, resulting in more pathogens entering the leaves. Moreover, the ROS levels in the npr1-1 mutant were higher than in the wild type, and several proteins involved in carbon fixation, oxidative phosphorylation, glycolysis, and glutathione metabolism were differentially changed in abundance. Our findings suggest that mobile SAR signals alter stomatal immune response possibly by initiating ROS burst, and the npr1-1 mutant has an alternative priming effect through translational regulation.

Morphology, Taxonomy, Anatomy, and Palynology of the Opium Poppy (Papaver somniferum L.) Cultivation in Northern Thailand.

In this paper, we present the morphology, taxonomy, anatomy, and palynology of Papaver somniferum. A detailed morphological description and illustrations of the species are provided, along with information about the identification, distribution, cultivation areas, habitats, pollinators, specimens examined, growing periods, phenology, etymology, vernacular name, and uses. The species can be characterized as a glabrous and glaucous herb with unlobed or pinnately lobed leaves, and an amplexicaul base; variations in color and morphological characteristics of petals; and white filaments, occasionally purple with a white basal part, broadened at the apical part. Two rings of discontinuous and widely spaced collateral vascular bundles are recognized in the transverse section of the stems. The shape of epidermal cells on the adaxial surface is polygonal, while that on the abaxial surface is polygonal or irregular. The anticlinal cell walls of the epidermal cells on the adaxial surface are straight or slightly curved, while those on the abaxial surface are straight, slightly curved, sinuate, or strongly sinuate. The stomata are anomocytic and are confined to the lower epidermis. The stomatal density is 54-199/mm2 (with a mean of 89.29 ± 24.97). The mesophyll is not distinctly differentiated into palisade and spongy regions. Laticifers are found in the phloem areas of the stems and leaves. The pollen grains can be spheroidal or prolate spheroidal in shape, sometimes oblate spheroidal [polar axis (P) diameter/equatorial axis (E) diameter ratio = 0.99-1.12 (with a mean of 1.03 ± 0.03)]. The pollen aperture is tricolpate and the exine sculpturing is microechinate.

Adaptation strategies of leaf traits and leaf economic spectrum of two urban garden plants in China

BackgroundPrevious studies of the relationships between traits have focused on the natural growth conditions of wild plants. Urban garden plants exhibit some differences in plant traits due to environmental interference. It is unknown whether the relationships between the leaf traits of urban garden plants differ under distinct climates. In this study, we revealed the variation characteristics of the leaf functional traits of trees, shrubs, and vines in two urban locations. Two-way ANOVA was used to reveal the response of plant leaf traits to climate and life forms. Pearson correlation analysis and principal component analysis were used to calculate the correlation coefficient between the leaf functional traits of plants at the two locations.ResultsLeaf dry matter content (LDMC) and vein density (VD) of different life forms in Mudanjiang were higher than those in Bozhou (P < 0.05), and the relative water content (RWC) in Bozhou was higher, whereas vein density (VD) of trees and shrubs in the two urban locations was significant (P < 0.05), but the vines were not significant. The photosynthetic pigments of tree and shrub species were larger in Mudanjiang, but the opposite was true for the vines. Both leaf vein density (VD) and stomatal density (SD) showed a very significant positive correlation in the two urban locations (P < 0.01), and both were significantly positively correlated with specific leaf area (SLA) (P < 0.05); and negatively correlated with leaf thickness (LT), and the relationship between pigment content were closer.ConclusionThe response to climate showed obvious differences in leaf traits of different life forms species in urban area, but the correlations between the traits showed convergence, which reflects that the adaptation strategies of garden plant leaves to different habitats are both coordinated and relatively independent.

Leaf cell wall properties and stomatal density influence oxygen isotope enrichment of leaf water.

Measurements of oxygen isotope enrichment of leaf water above source water (Δ18 OLW ) can improve our understanding of the interaction between leaf anatomy and physiology on leaf water transport. Models have been developed to predict Δ18 OLW such as the string-of-lakes model, which describes the mixing of leaf water pools, and the Péclet effect model, which incorporates transpiration rate and the mixing length between unenriched xylem and enriched mesophyll water in the mesophyll (Lm ) or veins (Lv ). Here we compare measurements and models of Δ18 OLW on two cell wall composition mutants grown under two light intensities and relative humidities to evaluate cell wall properties on leaf water transport. In maize (Zea mays), the compromised ultrastructure of the suberin lamellae in the bundle sheath of the ALIPHATIC SUBERIN FERULOYL TRANSFERASE mutant (Zmasft) reduced barriers to apoplastic water movement, resulting in higher E and, potentially, Lv and, consequently, lower Δ18 OLW . The difference in Δ18 OLW in cellulose synthase-like F6 (CslF6) mutants and wild-type of rice (Oryza sativa) grown under two light intensities co-varied with stomatal density. These results show that cell wall composition and stomatal density influence Δ18 OLW and that stable isotopes can facilitate the development of a physiologically and anatomically explicit water transport model.

Influence of seasonal variation to the population growth and ecophysiology of Typha domingensis (Typhaceae).

Precipitation is an important climatic element that defines the hydrological regime, and its seasonal variation produces annual dry and wet periods in some areas. This seasonality changes wetland environments and leverages the growth dynamics of macrophytes present, including Typha domingensis Pers. This study aimed to evaluate the influence of seasonal variation on the growth, anatomy and ecophysiology of T. domingensis in a natural wetland. Biometric, anatomical and ecophysiological traits of T. domingensis were evaluated over one year at four-month intervals. Reductions in photosynthesis were evidenced at the end of the wet periods and during the dry periods, and these reductions were associated with thinner palisade parenchymas. Increased stomatal indexes and densities as well as thinner epidermis observed at the beginning dry periods can be associated with higher transpiration rates during this period. The plants maintained their water contents during the dry periods, which may be related to the storage of water in leaf trabecular parenchyma, as this is the first time that results indicate the function of this tissue as a seasonal aquiferous parenchyma. In addition, increasing proportions of aerenchymas were evident during the wet periods, which may be related to a compensation mechanism for soil waterlogging. Therefore, the growth, anatomy and ecophysiology of T. domingensis plants change throughout the year to adjust to both the dry and wet periods, providing conditions for the survival of the plants and modulating population growth.

Functional traits underlie specialist-generalist strategies in whitebark pine and limber pine

Plant species life history strategies are described by functional variation spanning an acquisitive and conservative resource use continuum. Specialist species can exhibit traits promoting one end of the continuum, while generalist species can display traits promoting both acquisitive and conservative resource use. Whitebark pine (Pinus albicaulis, PIAL) and limber pine (Pinus flexilis, PIFL) are two high-elevation pines that have similar growth and morphology, yet contrasting elevational distributions with PIAL viewed as a specialist inhabiting a narrower elevation range, and PIFL as a generalist inhabiting a broader elevation range. We compared the physiological and morphological traits of greenhouse-grown 5-year-old PIAL and PIFL. Our results suggest that PIFL’s acquisitive and conservative resource use traits contribute to its generalist strategy and ability to inhabit a greater range of elevations than PIAL. PIFL had greater acquisitive resource use traits including: high-light tolerance (greater Qsat, greater fascicle density), increased biomass allocation to photosynthetic tissue (higher needle biomass, aboveground:belowground biomass, needle:branch + stem biomass), and higher C and water uptake (greater stomatal density and size, higher C assimilation rate), as well as greater conservative resource use traits including: greater physical stress resistance (shorter height, higher stem and branch diameters, greater branch and stem diameter:length), drought tolerance (higher SWC, leaf starch proportion), and drought avoidance (earlier budburst phenology, smaller hydroscape area) than PIAL. Our results suggest that PIFL may make more efficient use of high-light loads and maximize C and water uptake when moisture is abundant during spring snowmelt before the onset of dry summer conditions. Other conservative resource use traits describing cold tolerance, heat tolerance, and drought tolerance did not differ between species, suggesting that both species exhibit traits that promote similar conservative resource use enabling their overlapping persistence at higher elevations. Comparing the physiology of PIAL and PIFL within the same environment enables us to identify physiological mechanisms that underlie species establishment and survival, and how juvenile physiology contributes to their contrasting distributions and their generalist-specialist strategies.

Drought dampens the positive acclimation responses of leaf photosynthesis to elevated [CO2] by altering stomatal traits, leaf anatomy, and Rubisco gene expression in Pyrus

The responses of Chinese pear plantations to rising atmospheric CO2 concentration ([CO2]) and drought are crucial for accurately estimating pear production and forest carbon sink of China under future climate change. Here, we investigated the effect of CO2 enrichment on plant growth and leaf photosynthesis of Chinese pear trees grown under full irrigation and different levels of drought. We identified that leaf photosynthetic capacity and stomatal conductance increased by high [CO2] acclimation. However, such positive effects disappeared when drought occurred, especially under moderate and severe drought. This down-regulation of high [CO2] acclimation responses in leaf photosynthesis by drought was mainly caused by the decline in stomatal diffusional efficiency, thinner mesophyll tissues and smaller mesophyll cells. The decrease of stomatal diffusional efficiency was further caused by the reduced stomatal density and decreased regularity of stomatal distribution pattern under drought. Moreover, the down-regulation of those positive acclimation responses was relevant with the declines of carboxylation and photochemical efficiency of Rubisco, which was confirmed by the down-regulated expression levels of Rubisco coding genes. Overall, our results demonstrated that drought dampened the positive acclimation responses of leaf photosynthesis to elevated [CO2] by modifying stomatal morphology and distribution, leaf anatomy, and Rubisco gene expression. Therefore, under future climate change where CO2 enrichment is coupled with higher frequency of drought events, drought limitations should be incorporated into the current coupled climate-carbon models to avoid overestimation of the positive responses of Chinese pear plantations to elevated [CO2] and to accurately predict forest carbon sequestration.

Impact of Particulate Matter (PM10 and PM2.5) from a Thermoelectric Power Plant on Morpho-Functional Traits of Rhizophora mangle L. Leaves

A conventional thermoelectric plant (TP) in the sandy bar of the Tampamachoco Lagoon (Gulf of Mexico slope) emits particulate matter (PM) transporting trace metals that affect a mangrove forest. Wind transports the emission plume from north to south in the northerly wind season (NWS); the dry season (DS) showed calm periods. We analyzed whether PM2.5 and PM10 emissions from the TP and their trace metals impact Rhizophora mangle leaves. The experimental design included three sampling sites along the main lagoon axis (north to south) during the NWS and DS. Mangrove leaves were collected; PM was obtained with a cascade impactor and trace elements were analyzed by atomic absorption spectrophotometry. Leaves were measured and tested for metal and chlorophyll content, and for metal detection with SEM-EDX. Calm periods in the DS promote high atmospheric PM concentrations. Wet deposition in the NWS caused the highest trace metal deposition on mangrove leaves. A north-to-south gradient was identified on the mangrove forest, being the south site of the lagoon where lower chlorophyll and leaf area, higher stomatal width and density, and higher Cd concentrations were recorded. The morpho-physiological modifications observed on mangrove leaves affect functions such as photosynthesis and gas exchange.

Modelling Climate Using Leaves of Nothofagus cunninghamii—Overcoming Confounding Factors

Fossil leaf anatomy has previously been used as a proxy for paleoclimate. However, the exposure of leaves to sun or shade during their growth can lead to morphotype differences that confound the interpretation of fossil leaf anatomy in relation to climate and prevent reliable paleoclimate reconstruction. This work aims to model the differences in leaf anatomy that are due to various climatic drivers and differences attributable to sun or shade positions, using Nothofagus cunninghamii as the model species. Leaves from the sun and shade parts of three trees have been sampled from each of 11 sites in Victoria and Tasmania, Australia. The gross morphological and cuticular features have been scored and modelled with climate data from the sites. Random forest models can accurately predict Nothofagus cunninghamii contemporary climatic conditions of the spring temperature and summer rainfall based on leaf anatomical measurements. Leaf area, stomatal density and epidermal cell density are the most accurate predictors of whether a leaf grew in the sun or shade. Leaf area is also the strongest predictor of the maximum and minimum spring temperatures and rainfall. The models have implications for the use of fossilised leaves in paleoclimate reconstruction. The models we have built can be used to effectively predict whether a fossil leaf was from a sun or shade position on the tree and thus enable more reliable inference of paleoclimate by removing the confounding issues of variable leaf anatomy due to sun exposure during growth. Finally, these models could conceivably be used to make predictions of past paleoclimatic conditions provided suitable training and validation data on climatic conditions are available.

Rootstock-mediated carbohydrate metabolism, nutrient contents, and physiological modifications in regular and alternate mango (Mangifera indica L.) scion varieties.

Most of the popular scion varieties of mango possess alternate/irregular bearing. There are many external and internal factors assigned, among them carbohydrate reserves, and nutrient content plays important roles in the floral induction process in many crop species. In addition to that rootstock can alter the carbohydrate reserve and nutrient acquisition of scion varieties in fruit crops. The present investigation was carried out to understand the effect of rootstocks on the physiochemical traits of leaf, and bud and nutrient content in regular and alternate bearing varieties of mango. The rootstock "Kurukkan" promoted starch content in leaves of both alternate bearing varieties 'Dashehari' (5.62 mg/g) and regular 'Amrapali' (5.49 mg/g) and encouraged higher protein content (6.71 mg/g) and C/N ratio (37.94) in buds of alternate bearing 'Dashehari'. While Olour rootstock upregulated the reducing sugar in leaves of 'Amrapali' (43.56 mg/g) and promoted K (1.34%) and B (78.58 ppm) content in reproductive buds of 'Dashehari'. Stomatal density in 'Dashehari' scion variety was found higher on Olour rootstock (700.40/mm 2), while the rootstock fails to modify stomatal density in the scion variety regular bearer 'Amrapali'. Further, a total of 30 carbohydrate metabolism-specific primers were designed and validated in 15 scion/rootstock combinations. A total of 33 alleles were amplified among carbohydrate metabolism-specific markers, which varied from 2 to 3 alleles with a mean of 2.53 per locus. Maximum and minimum PIC value was found for NMSPS10, and NMTPS9 primers (0.58). Cluster analysis revealed that scion grafted on Kurukkan rootstock clustered together except 'Pusa Arunima' on Olour rootstock. Our analysis revealed that Fe is the key component that is commonly expressed in both leaf and bud. Although Stomatal density (SD) and Intercellular CO2 Concentration (Ci) are more specific to leaf and Fe, B, and total sugar (TS) are abundant in buds. Based on the results it can be inferred that the physiochemical and nutrient responses of mango scion varieties are manipulated by the rootstock, hence, the scion-rootstock combination can be an important consideration in mango for selecting suitable rootstock for alternate/irregular bearer varieties.

How Important Are Functional and Developmental Constraints on Phenotypic Evolution? An Empirical Test with the Stomatal Anatomy of Flowering Plants.

AbstractQuantifying the relative contribution of functional and developmental constraints on phenotypic variation is a long-standing goal of macroevolution, but it is often difficult to distinguish different types of constraints. Alternatively, selection can limit phenotypic (co)variation if some trait combinations are generally maladaptive. The anatomy of leaves with stomata on both surfaces (amphistomatous) present a unique opportunity to test the importance of functional and developmental constraints on phenotypic evolution. The key insight is that stomata on each leaf surface encounter the same functional and developmental constraints but potentially different selective pressures because of leaf asymmetry in light capture, gas exchange, and other features. Independent evolution of stomatal traits on each surface imply that functional and developmental constraints alone likely do not explain trait covariance. Packing limits on how many stomata can fit into a finite epidermis and cell size-mediated developmental integration are hypothesized to constrain variation in stomatal anatomy. The simple geometry of the planar leaf surface and knowledge of stomatal development make it possible to derive equations for phenotypic (co)variance caused by these constraints and compare them with data. We analyzed evolutionary covariance between stomatal density and length in amphistomatous leaves from 236 phylogenetically independent contrasts using a robust Bayesian model. Stomatal anatomy on each surface diverges partially independently, meaning that packing limits and developmental integration are not sufficient to explain phenotypic (co)variation. Hence, (co)variation in ecologically important traits like stomata arises in part because there is a limited range of evolutionary optima. We show how it is possible to evaluate the contribution of different constraints by deriving expected patterns of (co)variance and testing them using similar but separate tissues, organs, or sexes.

Changes in Stomatal Properties of Safflower Cultivars Under Salinity

The stomatal characteristics in the leaves play a key role to adapt to several abiotic stresses such as drought, heat, and salinity. This study was conducted at the Seed Science and Technology Laboratory, Eskişehir Osmangazi University in 2022 in order to examine the abaxial and adaxial stomatal properties of 9 safflower cultivars (Dinçer 5-18-1, Remzibey-05, Balcı, Yekta, Linas, Olas, Olein, Safir, and Zirkon) under salt stress (100 mM NaCl). The density, width, length, size, and index of the stomata were measured. The data was analyzed by a two-factor factorial in completely randomized design. The results showed that significant differences for all stomatal features of the safflower cultivars were determined. The stomata density changed with safflower cultivars between 143 and 57 number mm-2 and stomata size was observed as 510-698 µm2. The number of abaxial stomata was higher than the adaxial part of leaves and the stomatal density on the abaxial part of six safflower cultivars (Remzibey-05, Balcı, Yekta, Olas, Olein, and Safir) was decreased by salinity. In addition, abnormal stomata were observed in salt-affected cultivars of Dinçer 5-18-1, Remzibey-05, Yekta, Olein, and Zirkon. The stomata density mainly depended on genetic factors, suggesting that it should be used for separating safflower cultivars, but they declined considerably by salinity. It was concluded that stomatal properties should be considered to clarify the salt tolerance of safflower genotypes.

The Influence of LED Lights of Different Spectrum on the Development of &lt;i&gt;Lactuca sativa&lt;/i&gt;

The effect of light-emitting diode (LED) lamps with 5 different spectra on L. sativa plants (variety ‘Aficion’) grown in protected soil conditions was studied. Warm white light (WW) was used as a control (the ratio of blue, green and red portions in the spectrum was 14% : 48% : 38%). The maximum values of leaf size and fresh weight of the aerial parts were found in the RGB group (blue-green-red ratio 32% : 19% : 49%), highest values of dry weight and ash content – in the FS group (blue-green-red ratio 27% : 11% : 62%). Stomatal size and density on the abaxial leaf’s side was the highest in SB plants (blue-green-red ratio 33% : 41% : 38%). This was the most effective combination of parameters in terms of leaf architectonics. An increase in the portion of red light in the spectrum with a decrease in the portion of green light had a positive effect on the development of L. sativa plants, while an increase in the portion of green light in the spectrum positively affected-the stomatal apparatus formation.