Side Of Leaf Research Articles

First Report of Leaf Spot Caused by Pseudocercospora pruni-persicicola on Sweet Cherry in Korea.

Sweet cherry, Prunus avium (L.) L., is not much cultivated in Korea, with only 150 ha planted for domestic consumption. In September 2012, a previously unknown leaf spot was observed with nearly 100% incidence on trees (cv. Seneca) planted in a plastic greenhouse in Iksan City of Korea. Interestingly, the same cultivar as well as other cultivars planted outdoors did not show these symptoms. Leaf spots were irregular to subcircular, dark brown with or without a yellow halo, and becoming coalesced to cause leaf blight and premature defoliation. A cercosporoid fungus was consistently associated with disease symptoms. Fungal structures within the lesion developed on both leaf sides but mostly on the upper side. Stromata were well-developed, globular, dark brown, composed of textura angularis-globosa, and 30 to 80 μm in diameter. Conidiophores were densely fasciculate, pale olivaceous to pale brown, subcylindrical, geniculate-sinuous, 8 to 24 × 3 to 4 μm, and aseptate to 2-septate. Conidiogenous loci were inconspicuous, neither thickened nor darkened. Conidia were olivaceous, generally darker than conidiophores, cylindrical to obclavate, almost straight to mildly curved, short obconically truncate at the base, obtuse at the apex, 1- to 10-septate, constricted at the septa, 12 to 86 × 3.5 to 5 μm, guttulate, and had unthickened, not darkened hila. Morphological characteristics of the fungus were consistent with previous descriptions of Pseudocercospora pruni-persicicola (J.M. Yen) J.M. Yen (1,3). A voucher specimen was deposited in the Korea University herbarium (Accession No. KUS-F27264) and a monoconidial isolate was deposited in the Korean Agricultural Culture Collection (Accession No. KACC47019). The complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 (4) and sequenced. The resulting 505-bp sequence was deposited in GenBank (Accession No. KF670713). A BLAST search in GenBank revealed that the sequence showed >99% similarity with sequences of many Pseudocercospora species, indicating the close phylogenetic relationship of species in this genus. To conduct a pathogenicity test, a conidial suspension (~1 × 104 conidia/ml) was prepared in sterile water by harvesting conidia from 2-week-old cultures on V8 juice agar, and the suspension was sprayed until runoff onto the leaves of five healthy seedlings. Control plants were sprayed with sterile water. The plants were covered with plastic bags to maintain a relative humidity of 100% for 48 h and then transferred to a greenhouse. Necrotic spots appeared on the inoculated leaves 20 days after inoculation, and were identical to the ones observed in the field. P. pruni-persicicola was re-isolated from symptomatic leaf tissues, fulfilling Koch's postulates. Control plants remained symptomless. The fungus has previously been recorded on Prunus persica (L.) Stokes in Taiwan (2,3). To our knowledge, this is the first report of this fungus on P. avium globally as well as in Korea. The disease poses a new threat to the sweet cherry industry in Korea.

Epiphytic bryozoan community of Posidonia oceanica (L.) Delile leaves in two different meadows at disturbed and control locations

The impact of fish farming activities on Posidonia oceanica meadows in the Aegean Sea have been detected by using bryozoan epiphytes as indicators of disturbance. Samples were collected by SCUBA diving in September 2004 for comparing assemblages between disturbed (I1:0-5 m; I2:5-10 m and I3:10-15 m) and control meadows (C1:0-5 m; C2:5-10 m and C3:10-15 m) located at different depths. Regarding to mean percentage cover of bryozoans, significant differences were found between stations, leaf sides, depths and their interactions (p<0.05). Bryozoan species were colonized densely on back side of the adult leaves. Bantariella verticillata, Alcyonidium sp., Aetea truncata, Chorizopora brongniartii, Fenestrulina joannae were frequently observed species on P. oceanica leaves. B. verticillata showed statistically significant side and station differences while other species showed only significant side differences. Moreover, the mean coverage of Aetea truncata showed neither station nor side variations. B. verticillata could be evaluated as an appropriate key species for environmental changes. In the impacted meadow, higher mean coverage values of the species were particularly determined on front side of the leaves. These results suggest that characteristics of localities, leaf sides and leaf parts can be responsible factors on coverage value of epiphytic bryozoan species.

A quality assurance technique for the static multileaf collimator mode based on intrinsic base lines

The inspection of the static leaf positions of Multileaf Collimator (MLC) devices is essential for safe radiotherapy deliveries in both static and dynamic modes. The purpose of this study was to develop a robust, accurate and generic algorithm to measure the individual static MLC leaf positions. This was performed by extracting leaf tip locations from the radiographic film image and measuring their relative distance from a reference line on the film. The reference line was created with a selected set of MLC leaf sides. The film scaling was created and verified using the physical leaf width. The average measured distance corresponds to a leaf width of 10 mm was 9.95 ± 0.09 mm. The estimated reproducibility of the leaf tips location was ±0.26 mm. The code accuracy was checked by intentionally positioning set of leaves with small errors (1 mm), and the detected deviations from the expected positions ranged from −0.25 mm and +0.32 mm. The algorithm includes two self testing functions in order to detect failures of leaf positioning due to poor film quality and to avoid the potential systematic errors attributable to the improper collimator setting. The code is promising to be more efficient with Gafchromic and Electronic Portal Imaging Device (EPID).

Effect of wheat phosphorus status on leaf surface properties and permeability to foliar-applied phosphorus

This study aimed to analyse the effect of phosphorus (P) nutritional status on wheat leaf surface properties, in relation to foliar P absorption and translocation. Plants of Triticum aestivum cv. Axe were grown with three rates of root P supply (equivalent to 24, 8 and 0 kg P ha−1) under controlled conditions. Foliar P treatments were applied and the rate of drop retention, P absorption and translocation was measured. Adaxial and abaxial leaf surfaces were analysed by scanning and transmission electron microscopy. The contact angles, surface free energy and work-of-adhesion for water were determined. Wheat leaves are markedly non-wettable, the abaxial leaf side having some degree of water drop adhesion versus the strong repulsion of water drops by the adaxial side. The total leaf area, stomatal and trichome densities, cuticle thickness and contact angles decreased with P deficiency, while the work-of-adhesion for water increased. Phosphorous deficient plants failed to absorb the foliar-applied P. Phosphorous deficiency altered the surface structure and functioning of wheat leaves, which became more wettable and had a higher degree of water drop adhesion, but turned less permeable to foliar-applied P. The results obtained are discussed within an agronomic and eco-physiological context.

Dorsoventral asymmetry of photosynthesis and photoinhibition in flag leaves of two rice cultivars that differ in nitrogen response and leaf angle

Rice is believed to show photosynthetic symmetry between adaxial and abaxial leaf sides. To verify this, we re-examined dorsoventral asymmetry in photosynthesis, chlorophyll fluorescence and anatomical traits in flag leaves of two Oryza sativa cultivars that differ in nitrogen (N) response and in leaf angle: 'Akenohoshi', a cultivar that can adapt to low-N (LN), with low leaf angle (more erect leaves), and 'Shirobeniya', a cultivar that is unable to adapt to LN, with higher leaf angle. Plants were grown under standard-N (SN) and LN conditions. LN leaves of both cultivars became more erect than SN, but LN Akenohoshi still had more erect ones than Shirobeniya. Contrary to results of previous studies, leaves of both cultivars showed an asymmetry in photosynthetic rate between adaxial and abaxial sides (higher on the adaxial side) under SN. SN leaves of both cultivars showed lower susceptibility to photoinhibition on the adaxial side than on the abaxial side. However, leaves of Akenohoshi showed less asymmetry in these traits under LN than under SN, whereas leaves of Shirobeniya had similar degrees of asymmetry in these traits under both SN and LN. Both cultivars also showed dorsoventral asymmetry in anatomical traits of mesophyll tissue regardless of N level, but the degree of asymmetry was lower in LN Akenohoshi. These data reveal that rice leaves exhibit dorsoventral asymmetry in photosynthetic and anatomical features, and that the degree of asymmetry varies with cultivar and N level. It is suggested that lower leaf angles (particularly in Akenohoshi) in the presence of LN represent a light acclimation to prevent photoinhibition.

LEAFC3-N photosynthesis, stomatal conductance, transpiration and energy balance model: Finite mesophyll conductance, drought stress, stomata ratio, optimized solution algorithms, and code

A new, upgraded version of the LEAFC3-N model of combined photosynthesis, stomatal conductance, transpiration, and leaf energy balance is presented. The paper focuses mainly on simulating the effects of drought stress on diurnal time courses of leaf gas exchange by considering a finite variable mesophyll conductance. Further recent improvements are: (1) a model function accounting for the effect of different stomata frequencies at each leaf side on leaf conductance, (2) an accompanying dynamic model of plant water transport and storage to account for drought stress, (3) advanced solution algorithms, (4) clearly structured and well documented program code, (5) a user interface and simulation tool, and (6) a detailed documentation. The current model version was successfully re-calibrated against data of the diurnal time courses of net photosynthesis rate, stomatal conductance, and transpiration rate measured on wheat and barley leaves in the field and proved to account correctly for the reduction of these characteristics during midday and afternoon hours (midday depression) based on introducing a finite mesophyll conductance. With the current development we intend to provide a platform facilitating application and further improvement of the model. Documentation and source code may be provided by email request to the first author.

Morphology, histochemistry, and ultrastructure of foliar mucilage-producing trichomes of Harpagophytum procumbens (Pedaliaceae)

The morphology, histochemistry, and ultrastructure of foliar mucilage-producing trichomes of Harpagophytum procumbens are investigated using a combination of light and electron microscopy. The leaves of H. procumbens bear short and long glandular trichomes comprising 1 or 2 basal epidermal cells, a stalk of 1-3 cells, a short neck cell, and a head of 2-5 cells. These trichomes are distributed on both leaf sides with a greater abundance on the abaxial side. Both types of trichomes secrete copious amounts of secretion as droplets onto the leaf surface, and the release occurs through micropores in the head cuticles. The secreted material is mainly constituted of mucilaginous polysaccharides, in addition to phenolic compounds and total lipids. The stalk surfaces of long trichomes are densely covered by numerous micropapillae helping the mucilage droplets to slide onto the leaf surface. The short and long trichomes have a similar ultrastructure: the secretory head cells are cytoplasmically dense due to the abundance of mitochondria, ribosomes, small vacuoles, plastids, Golgi bodies, and elements of endoplasmic reticulum. Golgi-derived vesicles are developed in the head cells, and each plastid contains large starch grains.

Genetic diversity of a Serbian grapevine germplasm collection based on morphoagronomic characteristics

The objective of this study was to evaluate diversity and relationships among grapevine cultivars from the Serbian gene bank in Sremski Karlovci, and to identify the most useful variables for discrimination. A total of 54 grapevine cultivars have been studied. During the period 2000-2005, twelve quantitative and qualitative characteristics were evaluated using OIV categories to each trait. Characterization was done using multivariate statistical analyses: cluster and principal component analysis (PCA), Based on cluster analysis cultivars divided into three major groups and the clustering pattern was related to the classical eco-geographical grouping: occidentalis, pontica and orientalis. Beside geographic origin clustering position of cultivars throughout the dendrogram was related to main uses. The major part (70.1%) of the total variation presented was explained by four principal components. PC1 is highly correlated with the bunch and berry size and PC2 with the density of prostrate hairs of young shoot tip and the density of prostrate hairs between veins on the lower side of mature leaf. The overall arrangement of cultivars suggests considerable phenotypical (and presumably genetic) variability in studied germplasm collection. Furthermore, obtained results may be useful for further utilization of available genetic resources in gene bank managers, growing and breeding.

Micropropagation of bioencapsulation and ultrastructural features of sainfoin (Onobrychis viciifolia) grown in vivo and in vitro.

To explore the potential of in vitro rapid regeneration, three varieties (Golpaygan-181, Orumieh-1763, and Gorgan-1601) of sainfoin (Onobrychis viciifolia Scop. syn. Onobrychis sativa L.) were evaluated. For the first time, an encapsulation protocol was established from somatic embryogenic callus in torpedo and cotyledonary stages to create artificial seeds. Callus derived from different concentrations of Kinetin (0–2.0 mg L−1) and Indole-3-acetic acid (0–2.0 mg L−1) was coated with sodium alginate and subsequently cultured either in Murashige and Skoog (MS) medium or in soil substrate. Adventitious shoots from synthetic beads developed into rooting in full and half strength MS medium supplemented with various concentrations of auxin and cytokinin. Prolonged water conservation of black and red soils (1 : 1) had the highest rate of survival plantlets in the acclimatization process. Diverse resistance techniques in Onobrychis viciifolia were evaluated when the plants were subjected to water deficiency. Higher frequency of epicuticular waxes was observed in in vivo leaves compared to in vitro leaves. Jagged trichomes nonsecreting glands covered by spines were only observed in the lower leaf side. Ultimately, stomata indices were 0.127 (abaxial), 0.188 (adaxial) in in vivo and 0.121 (abaxial), 0.201 (adaxial) in in vitro leaves.

Morphology, anatomy and vasculature in leaves of Ginkgo biloba L. (Ginkgoaceae, Ginkgoales) under functional and evolutionary aspects

AbstractMorphology and anatomy of leaves as well as germination in Ginkgo biloba were studied and compared to the situation in other gymnosperms. The results show that a long‐shoot leaf will be replaced almost perfectly by the total leaf area of a single short‐shoot, a feature which can be found in nearly all deciduous angiospermous, but is absent in all other deciduous gymnosperms. The results of the anatomical investigations of cotyledons and their comparison with the situation in other gymnosperm groups e.g. Araucariaceae, Pinacaea and Taxaceae demonstrate that the recent hypogeal germination of Ginkgo biloba might represent a feature derived from an epigeal ancestor with cotyledons taking part in photosynthesis and respiration. The cotyledons of Ginkgo biloba, however, have only a storage and haustorial function today, but they are still rich in chlorophyll and stomata are developed all over both leaf sides, despite the fact that they are never exposed to light. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Super-hydrophobic and Super-oleophilic Properties of Taro Leaves and Their Application

The super-hydrophobic and super-oleophilic properties of taro leaves and their application were reported.The reasons that taro leaves possess super-hydrophobic and super-oleophilic properties were analyzed by static contact angle(CA) and scanning electron microscopy(SEM).The saturated oil absorption rate,sustained release and centrifugal oil retention of taro leaves dried at different temperatures were measured and analyzed by weighing method,sustained release property and centrifugation etc.The results show that the reverse side of the taro leaf is super-hydrophobic and its static water contact angle can reach 157.1° which is much larger than that of the front one(109.1°),and the sliding angles are not larger than 3°.It is also observed that the change of saturated oil absorption rate for the taro leaves shows certain regularity,and the highest saturated oil absorption(8.1 g / g) was obtained while the taro leaves dried at 200 ℃.Taro leaves own different capacity on fixing various oil spill.It can be known from results that taro leaves have strong capacity on fixing low volatile oil material and high centrifugal oil retention at high rotate speed.

Single-wavelength based rice leaf color analyzer for nitrogen status estimation

With the need of a tool for efficient nitrogen (N) fertilizer management in the rice field, this paper proposes a low-cost compact single-wavelength based colorimeter that can be used to indicate the specified six color levels of a rice leaf associated with the desired amount of N fertilizer for the rice field. Our key design is in a reflective optical architecture that allows us to investigate the amount of light scattered from only one side of the rice leaf. We also show how we implement this needed rice leaf color analyzer by integrating an off-the-shelf 562-nm wavelength light emitting diode (LED), a silicon photodiode, an 8-bit microcontroller, and a 6×1 LED panel in a compact plastic package. Field test results in rice fields confirm that leaf color levels of 1, 2, 3, 5, and 6 are effectively identified and their corresponding amount of N fertilizer can be determined. For the leaf color level of 4, our single-wavelength based rice leaf color analyzer sometimes indicates a higher color level of 5 whose suggested amount of N fertilizer is equal to that for the leaf color level of 4. Other key features include ease of use and upgradability for different color levels.

Shifts in stomatal traits following the domestication of plant species

Stomata are the major gates regulating substrate availability for photosynthesis and water loss. Although both processes are critical to yield and to resource-use efficiency, we lack a comprehensive picture on how domestication and further breeding have impacted on leaf stomata. To fill this gap, stomatal sizes and densities were screened in cultivated and wild ancestor representatives of a uniquely large group of 24 herbaceous crops. Anatomical data and gas-exchange models were combined to compute maximum potential conductance to water, separately for upper and lower leaf sides. The evolution of maximum conductance under domestication was diverse. Several crops increased, others decreased (noticeably high-conductance species), and others kept a similar potential conductance following domestication. It was found that the contribution of upper leaf sides to maximum conductance was statistically higher in cultivated than in wild ancestors. For crops showing this response, reduced stomatal density in the lower side of domesticated leaves was responsible for the observed 'adaxialization' of conductance. Increases in the size of stomata at the upper epidermis played a comparatively minor role. Nevertheless, this overall response was varied in magnitude and direction, signalling crop-wise specificities. Observed patterns reflect only potential conductances based on anatomical traits and should be used with care until actual physiological outcomes are measured. Together with advancements in the developmental genetics of stomata, our findings might hint at new breeding avenues, focused on stomata distribution. Provided urgent needs for increasing yields, the opportunities of enhancing traits of the physiological relevance of stomata should not be ignored.

Development of Xanthomonas fragariae populations and disease progression in strawberry plants after spray‐inoculation of leaves

Xanthomonas fragariae is the causative agent of angular leaf spot disease of strawberry. Greenhouse experiments were conducted using a X. fragariae isolate tagged with a green fluorescent protein (GFP) for detailed population dynamic studies in and on leaves after spray‐inoculation. The GFP‐tagged bacteria were monitored with dilution plating of leaf washings and leaf extracts, and analysis of intact leaves using a non‐invasive monitoring system called PathoScreen, based on laser radiation of fluorescent cells in plant tissues and signal recording with a sensitive camera. PathoScreen was also used to monitor bacteria grown on an agar medium after leaf printing. During the first 3 days after inoculation, bacterial populations washed off leaves rapidly decreased by at least a factor of 1000, after which populations remained stable until 14 days post‐inoculation (dpi), when symptoms first started to appear. Thereafter, populations increased to a level of 1012 colony‐forming units (CFU) g−1 of leaf material or higher. Similarly, densities in leaf extracts were low during the first 3 days after inoculation, at a level of 100–1000 CFU g−1 of leaf tissue. Gradually populations increased to a level of 109–1012 CFU g−1 at 28 dpi. Higher densities of epiphytic populations were found on the abaxial side than on the adaxial leaf side during the first 2 weeks after inoculation. After spray‐inoculation of leaves, bacterial populations released from infected plants remained low until symptoms appeared, after which plants became highly infectious, in particular under high humidity.

Leaf dimorphism in Thuja plicata and Platycladus orientalis (thujoid Cupressaceae s. str., Coniferales): the changes in morphology and anatomy from juvenile needle leaves to mature scale leaves

Thuja plicata and Platycladus orientalis initially produce only bifacial needle leaves. When the first lateral shoots develop, the leaf morphology and anatomy changes dramatically. Subsequently, only greatly reduced, bifacial scale leaves are developed. A new kind of “superimposed bifaciality” occurs with the change from juvenile needle leaves to mature scale leaves. Anatomical dorsiventrality affects not only the individual leaf, but also the complete plagiotropic lateral shoots of Thuja, which have a sun- and shade-exposed side. The upper light-exposed median leaves show adaxial leaf anatomy, contrary to the lower shaded median leaves showing abaxial leaf anatomy. Due to their mixed exposure, the lateral leaves show a lateral differentiation. At vertical lateral shoots of Platycladus, a predominant light-exposed side is absent. Thus, the anatomical dorsiventrality does not affect the complete shoot. Here the morphological abaxial side of a scale leaf becomes functionally and physiologically adaxial by reorientation of the palisade parenchyma and stomata. In juvenile needle leaves, the palisade parenchyma is located adaxial, with the majority of stomata being located abaxial. Conversely, in mature scale leaves, the palisade parenchyma is abaxial and the majority of stomata are adaxial.

SU‐E‐T‐05: The Effect of Leaf Corner Details in Sliding Windows Distributions, Implementation of Corrections in a Commercial Planning System

Purpose: The dosimetric effect of leaf tip corner details in sliding window dose distributions has been studied, a solution to account for this corner leakage has been designed and implemented. Methods: The dosimetric effect of leaf tip corner deviations from perfect 90 degree borders between the front face and leaf side, was analyzed for sliding window IMRT beams. The study was carried out using film, EPID and diode arrays on Elekta Linacs fitted with MLCi and MLCi2 MLC models. Although the effect is general and does not depend on a particular MLC model, the magnitude and distribution is dependent on MLC model. The study consisted of simple fields designed to de‐couple the combined effects of the leaf properties (transmission, interleaf leakage, tongue and grove, corner leakage), such that corner leakage could be quantified. An enhancement to the transmission filter of a commercial Monte Carlo treatment planning system (Monaco, Elekta AB) was implemented to account for this effect, allowing the user to model the corner leakage for individual leaf tip corners. Results: The analysis of test beams indicates that corner leakage will introduce additional fluence in sliding window IMRT distributions. Of the two mlc models studied, this effect is more important for MLCi, but is also present for MLCi2. Generally, corner leakage will be present in every mlc in which the corner is not perfectly cut at 90 degrees. In this light, small manufacturing differences give rise to small but visible effects on the dose distribution. Correct modeling of these small effects is increasingly important as users seek improved patient specific QA results, in particular using local gamma. Conclusion: In this work we study the effect of mlc leaf corner leakage in sliding window distributions, presenting a software implementation to model this effect in a Monte Carlo‐based Treatment Planning system. This work was funded by Elekta Inc.

SU‐E‐T‐261: Dosimetric Characterization and Comparison of the Elekta Agility and MLCi2 Multi‐Leaf Collimator Heads

Purpose: The new Elekta Agility™ radiation head with integrated 160 × 5mm inter‐digitating tungsten‐alloy leaves has been designed with leaf sides tilted to reduce overall transmission and leaf leakage. In this study, a comparison of the major dosimetric parameters of the Elekta Agility™ 160 leaf (5mm leaf width) multi‐leaf collimator (MLC) head design and the older Elekta MLCi2™ 80 leaf MLC head (10mm leaf width) is presented. Methods: Electron and photon beam data (including PDDs and profiles for various field sizes) were collected and analyzed using IBA hardware and software products for linac commissioning (i.e., IBA water tank, diodes, and OmniPro Accept™ 7). MLC transmission and leakage was measured using gafchromic film and SunNuclear MAPcheck2™. Results: Photon beams: Percent depth doses for 6MV and 10MV photon beams with various field sizes indicated little difference between the MLCi2™ and Agility™ heads (i.e., less than 1% difference at depths beyond dmax). Penumbra and umbra of dose profiles matched well for both energies; marginally differences were noticed on the toe‐side of large wedged‐fields. The average Agility™ MLC transmission was measured to be 0.4%, nearly an order of magnitude lower than the MLCi2™. Collimator scatter factors were nearly identical for small fields and reduced by as much as 1% for larger fields.Electron beams: PDDs of electron beam energies of 6, 9, 12, 15, and 18 MeV were collected, indicating little differences between the Elekta Infinity™ with the MLCi2™ and Agility™ heads. Conclusion: Analysis of the MLCi2™ and Agility™ beam data indicate little to no undesirable dosimetric differences; the largest deviation being a significant decrease in MLC transmission and leakage. These characteristics, combined with a significant increase in leaf speed, make the Elekta Agility™ a considerable improvement over the MLCi2™.

SU-E-T-522: Modeling the Agility MLC for Monte Carlo IMRT and VMAT Calculations

Purpose: The Agility multileaf collimator (MLC) mounted on an Elekta Synergy linear accelerator for 6 MV was modeled for IMRT and VMAT calculations using the BEAMnrc Monte Carlo (MC) code and verified versus measurements. Methods: To describe the Agility MLC in BEAMnrc, the available Component Module code was modified to include its characteristics; 5 mm leaf width, flat leaf sides with a focus point shifted from the radiation source. The MLC model was verified by comparison of the calculated interleaf leakage and tongue‐and‐groove effect for a closed MLC field and an irregular field to measurements with EBT2 film in a solid water phantom and diode measurements in a water phantom, respectively. We have developed a time dependent phase space data (PSD), which include a parameter based on MU index. Because leaf, jaw, collimator and gantry positions of each segment are controlled by MU index, this PSD enabled to simulate dynamic motions by interpolating positions between each segment. IMRT and VMAT calculations were compared with film measurements in a solid water phantom to validate the accuracy of the overall MLC model. MC statistical uncertainty was below 2% for all simulations. Results: We found a good agreement with our measurements on interleaf leakage. Agreement between mean calculated and measured leaf transmissions with fully opened jaws normalized to the center of a 10×10 cm2 field at the same depth was within 0.1%. Discrepancy between MC calculation and measurement for the irregular field was below 2%/2 mm. The gamma analysis of the comparison of MC and EBT2 film measurements in IMRT and VMAT fields showed 99.1%, 99.5% pass rates with 3%/3 mm criteria, respectively. Conclusion: The Agility MLC produced by Elekta could be accurately MC modeled with an adaptation in BEAMnrc. The MC model proved to be applicable for IMRT and VMAT calculations. Japan Society for the Promotion of Science (JSPS) Core‐to‐Core Program

Morphological and anatomical treats of Campanula trachelium L. leaves in steppe zone of Ukraine

Morphological and anatomical treats of Campanula trachelium L. leaves from 8 samples of different sites of seed origin have been studied. There were described labile and stable leaf treats of plants growing in the steppe zone of Ukraine. The labile treats, i.e. petiole length and its ratio to width of leaf blade, number of trichomes and stomata on adaxial leaf side, are not strongly relate with climatic conditions in seed origin sites. The stable treats, i.e. leaf blade size, thickness of epidermis and palisade mesophyll, relate with climatic parameters in sites of origin.

Glandular Trichomes and Essential Oil of Thymus quinquecostatus

The distribution and types of glandular trichomes and essential oil chemistry of Thymus quinquecostatus were studied. The glandular trichomes are distributed on the surface of stem, leaf, rachis, calyx and corolla, except petiole, pistil and stamen. Three morphologically distinct types of glandular trichomes are described. Peltate trichomes, consisting of a basal cell, a stalk cell and a 12-celled head, are distributed on the stem, leaf, corolla and outer side of calyx. Capitate trichomes, consisting of a unicellular base, a 1–2-celled stalk and a unicellular head, are distributed more diffusely than peltate ones, existing on stem, leaf, rachis and calyx. Digitiform trichomes are just distributed on the outer side of corolla, consisting of 1 basal cell, 3 stalk cells and 1 head cell. All three types of glandular trichomes can secrete essential oil, and in small capitate trichomes of rachis, all peltate trichomes and digitiform trichomes, essential oil is stored in a large subcuticular space, released by cuticle rupture, whereas, in other capitate trichomes, essential oil crosses the thin cuticle. The essential oil of T. quinquecostatus is yellow, and its content is highest in the growth period. 68 constituents were identified in the essential oils. The main constituent is linalool.