Side Of Leaf Research Articles

Behavioral aspects of Helicoverpa armigera in the cotton vegetative phase1

ABSTRACT Helicoverpa armigera (Hübner) is part of an important complex of insects-pests that attack the cotton crop. This study aimed to identify the preferential plant parts for the oviposition of moths, as well as the movement and feeding behavior of caterpillars, in the vegetative phase of the cotton cultivar BRS 369 RF. Plants emitting floral buds were used to study the oviposition behavior of moths. For this, a completely randomized design, with three treatments (adaxial and abaxial sides of the leaf and floral buds) and twenty replications (plants in pots), was used. In order to evaluate the behavior of the caterpillars in the cotton vegetative phase, another 3 × 5 factorial design, with nine replications, was used. The treatments were three ages (first, second and third instars) combined with five behaviors (walking, resting, waving, eating and drop-off). In this trial, the period of the day when caterpillars are more active was also evaluated. It was observed that H. armigera moths prefer to lay their eggs on the adaxial leaf side and on the last two nodes of the plant, in a descending direction. The adaxial leaf side is also the part of the plant preferred by caterpillars for walking, eating and resting, being this last behavior the most frequent in all instars. In general, the caterpillars walk more in the morning.

Use of morphological and anatomical characters to delimit varieties of Paliurus spina-christi Mill. (Rhamnaceae)

Introduction: Paliurus spina-christi Mill is a species with two varieties namely Paliurus spina-christi L. var. spina-christi and Paliurus spina-christivar. macrocarpa Beck native to mountains of Kurdistan, rarely growing in the upper plains of northern Iraq. Materials and Methods: A total of 15 plants from different parts of Kurdistan region were sampled. 30measurements for each characters of Leaf, Inflorescence, Flowers, Fruit, seeds, and leaf anatomical characters were measured for comparison between the two varieties. Results and Discussion: Fruit diameter of var. macrocarpa is significantly larger than fruit diameter of var. spina-christi. Most mean flower parts especially the ovary, in addition to seed size is larger in var. macrocarpa. Upper epidermal layer is always thicker than the lower epidermal layer for the same blade. The isobilateral mesophyll includes 2 layers of long palisade cells adaxially and 2-3 layers of short cells abaxially. Many vascular bundles are seen equally spaced in the mesophyll tissue.With the exception of the presence of simple hairs on the petiole adaxial side of the var. spina-cristi and the absence of these hairs from the same site of var. macrocarpa, all other anatomical features are considered to be of no taxonomic application. Stomatal density of the adaxial leaf side is up to 19 stomata per mm² in var. spina-christi while it is up to 38 stomata per mm² in var. macrocarpa. Conclusions: Both fruit diameter and the stomatal density of the adaxial leaf side constitute diagnostic characters for separating between the two varieties of Paliurus spina-christi Mill

A new method for modelling the tongue-and-groove in treatment planning systems

Commercial TPSs typically model the tongue-and-groove (TG) by extending the projections of the leaf sides by a certain constant width. However, this model may produce discrepancies of as much as 7%–10% in the calculated average doses, especially for the High Definition multi-leaf collimator (MLC) (Hernandez et al 2017 Phys. Med. Biol. 62 6688–707). The purpose of the present study is to introduce and validate a new method for modelling the TG that uses a non constant TG width. We provide the theoretical background and a detailed methodology to determine the optimal shape of this TG width from measurements and we fit an empirical function to the TG width that depended on two parameters and . Parameter represents the TG width and introduces a curvature correction in the width near the leaf tip end. The new TG model was implemented in MATLAB and when the curvature correction was zero () it caused the same discrepancies as the constant width model used by the Eclipse TPS. On the other hand, when the experimentally determined was used the new model’s calculations were in close agreement with measurements, with all differences in average doses 1%. Additionally, film dosimetry was used to successfully validate the potential of the new TG model to recreate the fine spatial details associated to TG effects. We also showed that the parameters , depend solely on the MLC design by evaluating three different linear accelerators for each MLC model considered, namely Varian’s High Definition and Millennium120 MLCs. In conclusion, a new method was presented that greatly improves the TG modelling. The present method can be easily implemented in commercial TPSs and has the potential to further increase their accuracy, especially for MLCs with rounded leaf ends.

Assessing water use and soil water balance of planted native tree species under strong water limitations in Northern Chile

Some forest plantations with native species are established in semiarid central Chile to compensate for industrial activities such as those of mining. Two of those operational forest plantations were monitored from age 1 to 3 years-old (2014–2016). Some plant attributes and soil volumetric water content (VWC) were monitored for eight native tree species (Acacia caven, Schinus polygamus, Porlieria chilensis, Lithraea caustica, Quillaja saponaria, Cryptocarya alba, Drimys winteri and Maytenus boaria), and a water balance model fitted to assess plant water use. Site preparation comprised planting holes of 40 cm × 40 cm by 50 cm in depth dug with a backhoe. Substrate was removed and mixed with compost in proportion 70:30 before mixing it in the planting hole. Planting holes acted as water reservoirs over the study period with soil VWC generally increasing with soil depth being also less variable deeper than in the upper soil layers. The ratio of adaxial (upper leaf side) to abaxial (lower leaf side) stomatal conductance approximately followed a species gradient from xeric to mesic. Irrigation represented about 26% and 53% of the total water input for the sclerophyll and the D. winteri plantation, respectively. At the plant level (0.4 × 0.4 m), soil evaporation and transpiration of D. winteri (273 and 232 mm year−1, equivalent to 43.7 and 37.1 L plant−1, respectively) were about twofold the values for the sclerophyllous/malacophyllous plantation (138 and 128 mm year−1, 22.1 and 20.5 L plant−1, respectively). We suggest the water budget for the sclerophyll/malacophyllous plantation was tight but feasible to be adjusted while for D. winteri irrigation was excessive, could be drastically reduced, and suppressed altogether if planted in gullies. We believe water balance models and soil moisture content sensors could be used to better plan and manage irrigation frequency and amounts in compensation forest plantations in semiarid central Chile.

Light intensity-regulated stomatal development in three generations of Lepidium sativum

Stomata are of crucial importance for CO2 uptake and the water economy of terrestrial plants. They evolve during the early phases of leaf development according to genetically conserved information modulated in its expression by environmental conditions. Mature leaves experience the environment, e.g. light intensity, and signal to younger developing leaves, modifying stomatal density (SD) and probably other leaf traits as well. In addition, the parental environment can affect the offspring’s phenotypes in an adaptive manner. However, the transgenerational effect of light on SD and interactions with the offspring’s light environment have not been studied so far. Here we compare transgenerational (parental) and growth-light (environmental) effects on SD. We grew three generations of garden cress (Lepidium sativum) in two contrasting light environments in a full factorial design. Stomatal and pavement cell densities (SD, PCD), 13C abundance as a proxy of leaf internal CO2 concentration (Ci), and leaf area were analysed in cotyledons and first true leaves of parental plants and two generations of offspring. Our results indicate that SD of offspring reflects both current and maternal light intensities. The transgenerational effect of light on SD was much smaller than the influence of current growth light and the former’s manifestation was dependent on light experienced by offspring. The cotyledons’ SD was unresponsive to variations in Ci but retained its light sensitivity, though it was smaller than in true leaves. High light reduced amphistomy in favour of the lower (abaxial) leaf side. SD and PCD were linearly proportional irrespective of light level, indicating invariant portions of spacing and amplifying cell divisions, and causing lower sensitivity of stomatal index at high SD. We show that light-stimulated stomatal development in garden cress differs in cotyledons and true leaves, varies between adaxial and abaxial leaf sides, and retains transgenerational information about environmental clues.

Variability in leaf wettability and surface water retention of main species in semiarid Loess Plateau of China

AbstractLeaf wettability, adhesion or repulsion of water drops, varies greatly among species and plays an important role in plant–soil hydrological relations. This study aimed to examine the variability in leaf wettability among species in different habitats and growth periods, and their relationships with plant surface water retention in the semiarid Loess Plateau of China. The leaf adaxial and abaxial contact angles, the surface water retention of leaves and individual plants, and general plant traits of 68 species belonging to 28 families were examined from May to August in 2017. Results showed that leaf water contact angles ranged from 27.3° to 133.4° and leaves with higher contact angles normally had lower variation coefficients. Leaf wettability was affected by internal properties (including leaf side, family, and leaf age) and external conditions (growth period), whereas the life form and slope aspect did not show significant effects. There were 47 species having higher contact angles on adaxial than abaxial surfaces, and the differences were significant in 23 species. Gramineous and leguminous species were more unwettable than compositae and rosaceous species. New leaves were more unwettable than old leaves. Surface wettability increased from May–June to July–August period. Leaf wettability was positively correlated with leaf surface water retention and was the best predictor of individual plant surface water retention compared with other plant traits. Leaf wettability showed interspecific differences associated with family and growth stage and can be a considerable variable in predicting canopy interception and evaluating vegetation hydrological function in drought environments.

Absorption of foliar-applied Zn in sunflower (Helianthus annuus): importance of the cuticle, stomata and trichomes.

The pathways whereby foliar-applied nutrients move across the leaf surface remain unclear. The aim of the present study was to examine the pathways by which foliar-applied Zn moves across the sunflower (Helianthus annuus) leaf surface, considering the potential importance of the cuticle, stomata and trichomes. Using synchrotron-based X-ray florescence microscopy and nanoscale secondary ion mass spectrometry (NanoSIMS), the absorption of foliar-applied ZnSO4 and nano-ZnO were studied in sunflower. The speciation of Zn was also examined using synchrotron-based X-ray absorption spectroscopy. Non-glandular trichomes (NGTs) were particularly important for foliar Zn absorption, with Zn preferentially accumulating within trichomes in ≤15 min. The cuticle was also found to have a role, with Zn appearing to move across the cuticle before accumulating in the walls of the epidermal cells. After 6 h, the total Zn that accumulated in the NGTs was approx. 1.9 times higher than in the cuticular tissues. No marked accumulation of Zn was found within the stomatal cavity, probably indicating a limited contribution of the stomatal pathway. Once absorbed, the Zn accumulated in the walls of the epidermal and the vascular cells, and trichome bases of both leaf sides, with the bundle sheath extensions that connected to the trichomes seemingly facilitating this translocation. Finally, the absorption of nano-ZnO was substantially lower than for ZnSO4, with Zn probably moving across the leaf surface as soluble Zn rather than nanoparticles. In sunflower, both the trichomes and cuticle appear to be important for foliar Zn absorption.

Coordinated variation between veins and stomata in cotton and its relationship with water-use efficiency under drought stress

Drought stress causes changes in vein and stomatal density. The objectives of this study were to determine (1) if the changes in vein and stomatal density are coordinated in cotton (Gossypium hirsutum L.) and (2) how these changes affect water-use efficiency (WUE). The results showed significant positive correlations between vein density and stomatal density when cotton was grown under different degrees of drought stress. WUE was significantly positively correlated with the densities of both veins and stomata. Stomatal pore area and stomatal density on the abaxial leaf side, but not the adaxial side, were significantly correlated with WUE, stomatal conductance, leaf net photosynthetic rate, and transpiration rate. In conclusion, coordinated changes in vein and stomatal density improve the WUE of cotton under drought stress. The abaxial leaf side plays a more important role than the adaxial side in WUE and gas exchange.

Contact angle measurements and water drop behavior on leaf surface for several deciduous shrub and tree species from a temperate zone

Key messageLeaf CA measurement should take into account angle variation during measurement time. Leaf wettability of common deciduous forest plants is characterized by wetting contact angles ranging from 60° to 140° with a significant variation between species of the same family.Leaf wettability is an important phenomenon that has an influence on several processes such as the hydrological cycle, plant pathogen growth, or pollutant and pesticide absorption/deposition. The main objective of this research was to investigate the leaf wettability differences of 19 species (16 trees and 3 shrubs) of deciduous plants commonly occurring in Polish forests (temperate climate). The measurements were gathered as follows: 20 undamaged leaves were selected for each species and the wettability was determined by contact angle measurements with an optical goniometer CAM 100 using the sessile drop method. The contact angle was measured with 1-s intervals during 2 min from droplet deposition on adaxial and abaxial leaf surface. Laboratory analyses were completed during the summer of 2016 during full vegetation growth. A general CA decrease with time was observed on both leaf sides. The contact angle values ranged from 60° to 140° depending on species and leaf side. Differences between contact angle values at the beginning and the end of measurement reached 23.6° and engendered changes of wetting classes for some species. In many cases, no wettability class change was observed despite a CA lowering of 20°. The abaxial side was found to be the more repellent for 14 out of 19 species. Altogether, the leaves were classified from highly wettable to highly non-wettable, probably depending on the plant-survival strategy.

Leaf dorsoventrality as a paramount factor determining spectral performance in field-grown wheat under contrasting water regimes.

The effects of leaf dorsoventrality and its interaction with environmentally induced changes in the leaf spectral response are still poorly understood, particularly for isobilateral leaves. We investigated the spectral performance of 24 genotypes of field-grown durum wheat at two locations under both rainfed and irrigated conditions. Flag leaf reflectance spectra in the VIS-NIR-SWIR (visible-near-infrared-short-wave infrared) regions were recorded in the adaxial and abaxial leaf sides and at the canopy level, while traits providing information on water status and grain yield were evaluated. Moreover, leaf anatomical parameters were measured in a subset of five genotypes. The spectral traits studied were more affected by the leaf side than by the water regime. Leaf dorsoventral differences suggested higher accessory pigment content in the abaxial leaf side, while water regime differences were related to increased chlorophyll, nitrogen, and water contents in the leaves in the irrigated treatment. These variations were associated with anatomical changes. Additionally, leaf dorsoventral differences were less in the rainfed treatment, suggesting the existence of leaf-side-specific responses at the anatomical and biochemical level. Finally, the accuracy in yield prediction was enhanced when abaxial leaf spectra were employed. We concluded that the importance of dorsoventrality in spectral traits is paramount, even in isobilateral leaves.

OsGATA7 modulates brassinosteroids-mediated growth regulation and influences architecture and grain shape.

OsGATA7 modulates brassinosteroids-mediated growth regulation and influences architecture and grain shape.

How many leaves are enough? The influence of sample size on estimates of plant developmental instability and leaf asymmetry

One issue in studies of leaf asymmetry is the lack of standardization of sample sizes for estimating the different types of leaf asymmetry, namely fluctuating asymmetry (FA –, differences in leaf sides around zero, normally distributed data), directional asymmetry (DA – one leaf side is substantially larger than the other) and antisymmetry (AS – both right-and left-sidedness; bimodal data). FA is the only parameter regarded as a biomarker of stress and it is used consistently for population monitoring. Here we investigated whether leaf samples of different sizes showed different asymmetries (FA, DA or AS) in three unrelated plant species (Miconia fallax, Solanum lycocarpum and Bauhinia brevipes). We hypothesized that larger samples would show FA, as substantial side differences would be buffered and so that the sample would display differences in leaf sides around zero (i.e., FA). The results were highly dependent on both sample size and plant species. Larger samples did not consistently display FA, but they did provide leaf asymmetry values close to zero, which is a prerequisite of FA. AS was pervasive, but detailed exploration of histograms revealed that none of the data sets had a bimodal distribution and most curves were leptokurtic. On this basis, we suggest that kurtosis tests in combination with histograms should be given preference over normality tests as a method to evaluate potential AS. We conclude that at this time it is still not possible to give a rule-of-thumb for sample sizes for this type of investigation, and that graphical representations of data should be used to classify the asymmetry types more accurately. We suggest that the statistical tests used to examine FA should be reconsidered and that graphs such as histograms can be more informative than p-values when it comes to distinguishing between types of leaf asymmetry.

Effects of Salt Stress on Plant Growth, Antioxidant Capacity, Glandular Trichome Density, and Volatile Exudates of Schizonepeta tenuifolia Briq.

Salinity is a major abiotic factor affecting plant growth and secondary metabolism. However, no information is available about its effects on Schizonepeta tenuifolia Briq., a traditional Chinese herb. Here, we investigated the changes of plant growth, antioxidant capacity, glandular trichome density, and volatile exudates of S. tenuifolia exposed to salt stress (0, 25, 50, 75, 100 mM NaCl). Results showed that its dry biomass was reduced by salt treatments except 25 mM NaCl. Contents of antioxidants, including phenolics and flavonoids, increased at low (25 mM) or moderate (50 mM) levels, but declined at severe (75 and 100 mM) levels. On leaf surfaces, big peltate and small capitate glandular trichomes (GTs) were found. Salt treatments, especially at moderate and severe concentrations, enhanced the density of total GTs on both leaf sides. The most abundant compound in GT volatile exudates was pulegone. Under salinity, relative contents of this component and other monoterpenes decreased significantly; biosynthesis and accumulation of esters were enhanced, particularly sulfurous acid,2-ethylhexyl hexyl ester, which became the second major compound as salinity increased. In conclusion, salt stress significantly influenced the growth and secondary metabolism of S. tenuifolia, enabling us to study the changes of its pharmacological activities.

First Report of Rust Caused by Puccinia arachidis on Peanut in South Carolina

Puccinia arachidis Speg. (phylum Basidiomycota, class Pucciniomycetes) causes rust on peanut (Arachis hypogaea L.) and is a biotroph. In September 2016, several plants exhibiting numerous rust-colored pustules characteristic to peanut rust (Subrahmanyam 1997) on abaxial leaf sides were observed in two plots (12.19 × 12.67 m) at approximately 5% incidence of total leaflets (≈3% severity) in a localized area of approximately 2 × 2 m in a peanut field in Blackville, SC (Barnwell County) on the commercial variety ‘Georgia 12Y’. Also in September, identical symptoms were observed in a localized area of approximately 3 × 3 m (80% leaflet incidence, 40% severity) in a commercial field (≈40 hectares) of ‘Georgia 06G’ (industry-standard runner variety) in Orangeburg County, SC. Both locations were managed under reduced fungicide programs. The Barnwell County location received four applications of chlorothalonil alone as part of a separate disease study, whereas the Orangeburg County field received five chlorothalo...

First Report of Leaf Rust on Southern Highbush Blueberry caused by Thekopsora minima in California

Leaf rust symptoms have been intermittently observed on southern highbush blueberry (Vaccinium corymbosum L. × V. darrowii Camp) in California. Rust symptoms were first seen in 2010 near Carpinteria, CA (M. Kong, personal communication) and then in July 2016 on leaves of three blueberry cultivars Emerald, Jewel, and Snow Chaser in a field trial in Watsonville. In early 2017, leaf rust was observed again in Watsonville on the same cultivars and on various 3-year-old plants. Symptoms were found primarily on older leaves. Purplish-brown necrotic spots were present on the adaxial leaf surface, while the abaxial leaf side exhibited orange to yellow colored uredinia. Upon closer inspection using a light microscope, the uredinia were clustered on the leaf surface, ovoid in shape, and approximately 100 to 400 μm in diameter. Certain rust species possess ostiolar cells projections near the ostiole of the uredinium, which aid in taxonomic identification; however, ostiolar cells were not observed. Each uredinium contained numerous ellipsoid urediniospores with spines that emanated from the spore walls. When measured, urediniospores were 17.5 to 30 × 17.5 to 20 μm (average 24 × 19 μm, n = 25). Leaf samples with rust signs and symptoms were taken and stored at 4°C for further taxonomic examination. Potential alternate hosts (i.e., Tsuga spp.) for blueberry leaf rust were not present. After morphological evaluation, the rust pathogen was identified as Thekopsora minima P. Syd. & Syd. and two specimens from different plants were sent to the U.S. National Fungus Collection (BPI 910346 and BPI 910349) (Sato et al. 1993; Schilder and Miles 2011). DNA was extracted from six samples and two loci amplified from each sample. A 1,410-bp fragment spanning 5.8S-ITS2-28S rDNA was amplified with Rust2inv and LR6 primers (fragment 1) and a 1,697-bp fragment spanning the 18S rDNA was amplified with Rust18S-R and NS1 primers (fragment 2) (Aime 2006). Fragment 1 shared 100% identity (1,007 of 1,007 bp) with a T. minima isolate (BRIP57654) that infected V. corymbosum from Australia; fragment 2 shared >99% identity (1,207 of 1,210 bp) with the same isolate (accession nos. KC763340 and KT199391, respectively). Sequences for fragment 1 and fragment 2 from isolate (001) were deposited in GenBank (KY991374 and KY991375, respectively). Although another rust, Naohidemyces vaccinii, has been reported on V. membranaceum Douglas ex Torr. in CA, recent reports of T. minima in Australia, China, Mexico, South Africa, and in several states in the U.S. (OR, MI, DE, NY) suggest that T. minima is the most commonly encountered pathogen causing leaf rust on northern and southern highbush blueberries (Schilder and Miles 2011; Wiseman et al. 2016). To our knowledge, this is the first report of T. minima on any plant species within CA. In 2017, another rust species was found in Rubus spp. that was unobserved in CA previously, which could be related to significant winter precipitation (Shands et al. 2018). Since the alternate host Tsuga spp. is outside the central coast region of CA, further research is necessary to understand the epidemiology of T. minima in CA.

Identification of light availability in different sweet cherry orchards under cover by using non-destructive measurements with a Dualex™

Changing climatic conditions makes the development of cultivation strategies for protected cherry cultivation necessary. The objective of the present study was to investigate physiological processes in connection with light availability in different planting systems under cover using a Dualex™ for non-destructive measurements. Hence, cherry trees were either trained as hedgerows, i.e. the most dense planting ([2.35 m*2]*1.5 m), or trained as spindles (2.70 m*2.0 m; 1.75 m*2.9 m) and grown under cover or in the open field at Klein-Altendorf near Bonn, Germany. There was no difference in leaf area between the plantings. Non-invasive measurements with the Dualex™ (Force A, France) showed that a larger relative leaf chlorophyll content (Chl = 30–33) in the hedgerow trees under crop cover as a result of less light than in the open field-grown leaves with less chlorophyll (ChI = 26–28). Similarly, the flavonoid index (Flav), as a relative measure of the epidermal flavonoids and light condition, was generally lower under crop cover and lowest in the hedgerow trees on the adaxial leaf side with Flav = 1.4–1.5 relative to 1.6–1.8 in the open field, but always maintained these high values above the critical light level of 1–1.2. Non-invasive SunScan measurements showed light reductions of up to 80% inside the canopy of the dense hedgerow trees under cover in line with the lowest values for Flav and ChI. Although the largest yield per tree was obtained in the planting system with the best light conditions (1.75 m*2.9 m), the largest yield per acreage was found in the most dense planting (2.7 m*2.0 m) with hedgerows under cover as an ideal combination of a high yield and fruit quality with good light availability. Overall, our results showed that light availability depends on crown structure, planting system and tree density. The indices Flav and ChI offer the possibility to evaluate the light conditions in an orchard easily and to give a recommendation for an optimized growing system.

The ecophysiology of leaf cuticular transpiration: are cuticular water permeabilities adapted to ecological conditions?

When the stomata are closed under drought, the only route for water loss from the leaf interior to the atmosphere is across the cuticle. Thus, the extent of cuticular transpiration in relation to the reservoirs of water in the plant and the water acquisition from the soil determines the fitness and survival of the plant. It is, therefore, widely assumed that the cuticular water permeability of plants regularly experiencing drought is comparatively low and, thus, adapted to the environment. To test this hypothesis, 382 measurements of cuticular permeability from 160 species were extracted from the literature published between 1996 and 2017. The data had been produced either by using isolated cuticles and astomatous leaf sides or by measuring the minimum leaf conductance under conditions assumed to induce maximum stomatal closure. The species were assigned to 11 life form groups. Except for two particular cases (epiphytes, and climbers and lianas), the cuticular permeabilities of all groups either did not differ significantly or the available data did not allow a statistical test. In conclusion, present knowledge either does not support the hypothesis that ecological adaptions of cuticular water permeability exist or the available data are insufficient to test it.

Histological and Antimicrobial Study of Ononis Arvensis L.

In this study field restharrow (Ononis arvensis) was investigated for histological and antimicrobial features. The aerial part and the root were embedded in synthetic resin and investigated following sectioning by a rotation microtome. The antimicrobial activity and minimum inhibitory concentration of the solvent fractions of the aerial part were studied against four bacterial strains and one fungus. According to histology, the root covered by rhizodermis contains contiguous vascular elements, which are surrounded by sclerenchyma cells. The epidermis cells are anisodiametric in the stem, sepal, and petal. The bundles of the stem form a Ricinus type thickening. The adaxial side of the heterogeneous leaf is covered by unbranching non-glandular and capitate glandular trichomes. The stipule, petiole, sepals and petals are isolateral having mesomorphic stomata. Pollen grains are tricolpate. The different extracts of the herb showed antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium, Staphylococcus aureus, and Candida albicans. Data show that the extracts of the leaf contain compounds which may be responsible for the antifungal effect, while extracts obtained from display against the tested bacteria, except Escherichia coli. Further studies are required to complete the phytochemical analysis and identify the antimicrobial compounds of extracts.

Morphological Variation of Two Cultivated Types of Perilla Crop from Different Areas of China

To better understand the morphological variation for Perilla crop in different areas of China, we studied the morphological variation in 87 accessions (84 cultivated var. frutescens and three cultivated var. crispa ) from high latitude (Northeast China) and middle latitude (North and Northwest China) areas of China by examining seven quantitative and 10 qualitative characters. Analysis of the morphological variation determined that there was significant morphological differences in five quantitative traits between cultivated var. frutescens and cultivated var. crispa , including effective number of branches (QN2), number of internodes (QN3), number of branches (QN4), length of the largest inflorescence (QN5), and days from germination to flowering (QN7). However, two quantitative traits-plant height and number of florets of the largest inflorescence-did not show any significant differences between cultivated var. frutescens and cultivated var. crispa . In addition, significant differences for six quantitative traits were found between the accessions of cultivated var. frutescens originating from high and middle latitude areas in China, which included QN2, QN3, QN5, number of florets of the largest inflorescence (QN6), and QN7. Principal components analysis (PCA) identified five quantitative characters [plant height (QN1), QN2, QN3, QN4, QN7] and six qualitative characters [fragrance of plant (QL1), color of reverse side of leaf (QL3), degree of pubescence (QL5), color of flower (QL6), shape of leaf (QL7), and hardness of seed (QL10)] that contributed to the positive direction on the first axis. The other quantitative and qualitative characters contributed to the negative direction on the first axis. Most accessions of cultivated var. frutescens and cultivated var. crispa were clearly separated by the first axis. In addition, most accessions of cultivated var. frutescens are from high latitude and middle latitude areas that were clearly separated by the first axis, except for several accessions. The findings from this study will provide useful information towards understanding the morphological variation of Perilla crop according to geographical distribution in high and middle latitude regions of China.

On the use of dorsiventral reflectance asymmetry of hornbeam (Carpinus betulus L.) leaves in air pollution estimation.

This study examines the role of dorsiventral leaf measurements in reflectance-based air quality estimation. The dorsiventral asymmetry is used to describe the difference between the upper (adaxial) and lower (abaxial) leaf side. Spectral characteristics of dorsiventral asymmetry and both adaxial and abaxial leaf reflectance are investigated for a typical dicotyledonous species Carpinus betulus used in an urban environment. The link with traffic-related air pollution is established and the potential for monitoring of air quality is evaluated. We conclude that dorsiventral reflectance asymmetry is a factor that should not be ignored in canopy measurements and modeling. On the other hand, the benefits of dorsiventral asymmetry indices as a tool for reflectance-based air quality seem limited.