Adaxial Palisade Research Articles

Anatomical-Foliar Diversity of Agave salmiana subsp. salmiana (Asparagaceae) in Three Populations of the Teotihuacán Region (Mexico).

Agave salmiana Otto ex Salm-Dyck is an endemic Mexican plant distributed from 1230 to 2460 m above sea level, native to the arid zones of central and southern Mexico. It is a traditionally used species, with morphotypes ranging from wild to cultivated, with an ample cultural and management history. The species is important because it generates employment, and its products are used for self-consumption and are marketed as raw materials; however, little is known about its leaf anatomical description or studies that report the variation in its characters in terms of its level of management and its altitudinal gradient. To address this, we collected leaf samples from three localities of the Teotihuacan region in the State of Mexico (Mexico) and obtained anatomical leaf sections; with these, we also obtained thirty-eight parameters to quantitatively describe leaf anatomy. Thus, in this study, the general anatomical description of the leaf of Agave salmiana subsp. salmiana is presented. Unique leaf characters and others shared with the species of the genus were identified for the leaf of A. salmiana subsp. salmiana. In addition, significant variation was observed when comparing the three sampled localities (78.95%). From the analysis of anatomical characters, abaxial outer periclinal wall length, length of adaxial palisade parenchyma cells, fiber length, surface area of abaxial epidermal cells, width of abaxial palisade parenchyma cells, and total length of parenchyma in adaxial palisade were found to distinguish individuals from the three localities analyzed and the differences are related to management and altitude gradients.

Quality Studies on Cynometra iripa Leaf and Bark as Herbal Medicines.

Cynometra iripa Kostel. is a Fabaceae species of mangrove used in traditional Ayurvedic medicine for treating inflammatory conditions. The present study aims to establish monographic botanical and chemical quality criteria for C. iripa leaf and bark as herbal substances and to evaluate their in vitro antioxidant potential. Macroscopic and microscopic qualitative and quantitative analyses, chemical LC-UV/DAD-ESI/MS profiling, and the quantification of key chemical classes were performed. Antioxidant activity was evaluated by DPPH and FRAP assays. Macroscopically, the leaf is asymmetrical with an emarginated apex and cuneate base. Microscopically, it shows features such as two-layered adaxial palisade parenchyma, vascular bundles surrounded by 3-6 layers of sclerenchyma, prismatic calcium oxalate crystals (5.89 ± 1.32 μm) along the fibers, paracytic stomata only on the abaxial epidermis (stomatal index-20.15), and non-glandular trichomes only on petiolules. The microscopic features of the bark include a broad cortex with large lignified sclereids, prismatic calcium oxalate crystals (8.24 ± 1.57 μm), and secondary phloem with distinct 2-5 seriated medullary rays without crystals. Chemical profile analysis revealed that phenolic derivatives, mainly condensed tannins and flavonoids, are the main classes identified. A total of 22 marker compounds were tentatively identified in both plant parts. The major compounds identified in the leaf were quercetin-3-O-glucoside and taxifolin pentoside and in the bark were B-type dimeric proanthocyanidins and taxifolin 3-O-rhamnoside. The total phenolics content was higher in the leaf (1521 ± 4.71 mg GAE/g dry weight), while the total flavonoids and condensed tannins content were higher in the bark (82 ± 0.58 mg CE/g and 1021 ± 5.51 mg CCE/g dry weight, respectively). A total of 70% of the hydroethanolic extracts of leaf and bark showed higher antioxidant activity than the ascorbic acid and concentration-dependent scavenging activity in the DPPH assay (IC50 23.95 ± 0.93 and 23.63 ± 1.37 µg/mL, respectively). A positive and statistically significant (p < 0.05) correlation between the phenol content and antioxidant activity was found. The results obtained will provide important clues for the quality control criteria of C. iripa leaf and bark, as well as for the knowledge of their pharmacological potential as possible anti-inflammatory agents with antioxidant activity.

Anatomical and histochemical characterization of Syzygium travancoricum Gamble (Myrtaceae).

Syzygium travancoricum Gamble popularly known as "Kulavettimaram" or "Kulirmaavu" is a least explored endemic endangered taxa of Southern Western Ghats, Kerala. The species is often misidentified due to its close resemblance with allied species and no other studies have been reported on the anatomical and histochemical characters of this species. This article aims to evaluate the anatomical and histochemical characteristics of various vegetative parts of S. travancoricum. Anatomical and histochemical characters of bark, stem, and leaf were analyzed using standard microscopic and histochemical procedures. S. travancoricum possessed distinct anatomical characters such as, paracytic stomata, arc shaped midrib vasculature, continuous sclerenchymatous sheath around the midrib vascular region, single layer of adaxial palisade layer, presence of druses, and quadrangular cross section contour of stem which could be combined with additional morphological and phytochemical characteristics, relevant for species identification. The bark showed the presence of lignified cells, isolated groups of fibers and sclereids, starch depositions and druses. Stem has quadrangular outline with well-defined periderm. The petiole and the leaf blade have abundance of oil glands and druses with paracytic stomata. The anatomical and histochemical characterization are potential tools for the delineation of confusing taxa and provide substantial evidence to their quality control.

Structural plasticity in leaves of Schinus terebinthifolius (Anacardiaceae) populations from three contrasting tropical ecosystems1

Schinus terebinthifolius Raddi (Anacardiaceae) is a pioneer tropical species that has been largely used in Brazil for land restoration. The species occurrence encompasses inland ecosystems such as the neotropical savanna (cerrado sensu stricto; Cerrado domain) through coastal ecosystems such as mangroves and the restinga (Atlantic Forest domain), all of which are characterized by environmental factors that highly contrast with one another. We analyzed the leaf anatomy of S. terebinthifolius populations from those three ecosystems aiming to verify whether any particular trait would provide the species with foliar anatomical plasticity, thereby enabling it to adapt to such environmentally disparate areas. We found that thickness of the leaf blade, adaxial palisade parenchyma, and spongy parenchyma differed significantly among the three ecosystems. The population from the restinga, an open, coastal ecosystem subjected to high light incidence, showed the highest means for these variables, followed by the populations from mangrove and cerrado. Leaf blade thickness in the restinga population was higher due mainly to increased palisade parenchyma thickness. The adaxial palisade parenchyma thickness in mangrove individuals was more than double the one in the cerrado population. The abaxial palisade parenchyma thickness showed no difference between the mangrove and restinga populations, yet in those two it was higher than in the cerrado population. Schinus terebinthifolius was revealed to have high potential of acclimating to different ecosystems, owing to a high capacity of developing anatomical responses to distinct stress conditions imposed by the surrounding environment, which confirms the species high phenotypic plasticity. Such high capacity of acclimating to contrasting environmental conditions by means of modulating the thickness of different leaf tissues could provide the species with an adaptive advantage in a climate-change scenario.

Effect of expansion time and sunlight radiation on the functional and anatomical traits of mango tree leaves

The mango tree (Mangifera indica L.) is cultivated on a large scale in Brazil for economic purposes. Since the leaves, as the main photosynthetic organs, play an essential role in fruit production, the primary objective of the present study was to analyze comparatively the morphologicalcharacteristics of leaves at different stages of expansion and of leaves exposed to different levels of solar radiation. Leaves were collected at the beginning of expansion, during intermediate expansion and when completely expanded, and sun and shade leaves were compared. The individuals were adult plants without flowers and fruits located along the South Lake, Brasília. The leaves were analyzed for area, specific leaf area (SLA), thickness, water content and anatomical traits. Data were analyzed by ANOVA post hoc Tukey test to test the influence of leaf expansion time and by the T-test to determine the effect of radiation (α = 5%). Greater scleromorphy was observed in the completely expanded leaves compared to the leaves at the beginning of expansion, with lower water content and SLA in completely expanded leaves. Higher sclerophyll content was observed in sun leaves than in shade leaves, with lower SLA, greater leaf thickness and greater thickness of adaxial epidermis, palisade parenchyma and mesophyll in sun leaves. Based on these results, greater care is indicated regarding leaf management at the beginning of expansion and the management of shade leaves, since they aremore susceptible to damage from herbivores. The objective of this management is to maximize fruit production.

Anatomically Preserved Early Cretaceous Bennettitalean Leaves: Nilssoniopteris corrugata n. sp. from Vancouver Island, Canada

Early Cretaceous fossilized leaves assignable to the extinct seed plant order Bennettitales occur within an exceptionally diverse Early Cretaceous (Valanginian) flora of anatomically preserved plant fossils at Apple Bay on Vancouver Island, British Columbia, Canada. One of the bennettitalean leaf types has an entire margin, with laminae that are attached near the adaxial surface of the midvein. Leaves are 10–15 mm wide with an adaxial surface that shows distinct corrugations, and a midrib that is exposed adaxially. The vascular system of the midrib consists of a crescent-shaped ring of collateral bundles. Lateral veins diverge from midrib at ∼90°, are typically simple but occasionally branch at base of the lamina. Vein density is 12–15 per cm. Leaves are hypostomatic with syndetocheilic stomata that are randomly oriented between veins. Internal anatomy consists of an adaxial hypodermis of closely-spaced isodiametric cells, mesophyll that is differentiated into adaxial palisade and abaxial spongy zones, and collateral bundles that show a distinct bundle sheath with bundle sheath extensions. This novel combination of characters represents the diverse bennettitalean genus Nilssoniopteris. Nilssoniopteris corrugata new species is only the second species of the genus for which internal anatomy is preserved. This species increases the known variation of bennettitalean leaf anatomy, and reinforces our appreciation for the global distribution of bennettitalean seed plants during the Mesozoic.

Anatomically Preserved Early Cretaceous Bennettitalean Leaves: Nilssoniopteris corrugata n. sp. from Vancouver Island, Canada

Early Cretaceous fossilized leaves assignable to the extinct seed plant order Bennettitales occur within an exceptionally diverse Early Cretaceous (Valanginian) flora of anatomically preserved plant fossils at Apple Bay on Vancouver Island, British Columbia, Canada. One of the bennettitalean leaf types has an entire margin, with laminae that are attached near the adaxial surface of the midvein. Leaves are 10–15 mm wide with an adaxial surface that shows distinct corrugations, and a midrib that is exposed adaxially. The vascular system of the midrib consists of a crescent-shaped ring of collateral bundles. Lateral veins diverge from midrib at ∼90°, are typically simple but occasionally branch at base of the lamina. Vein density is 12–15 per cm. Leaves are hypostomatic with syndetocheilic stomata that are randomly oriented between veins. Internal anatomy consists of an adaxial hypodermis of closely-spaced isodiametric cells, mesophyll that is differentiated into adaxial palisade and abaxial spongy zones, and collateral bundles that show a distinct bundle sheath with bundle sheath extensions. This novel combination of characters represents the diverse bennettitalean genus Nilssoniopteris. Nilssoniopteris corrugata new species is only the second species of the genus for which internal anatomy is preserved. This species increases the known variation of bennettitalean leaf anatomy, and reinforces our appreciation for the global distribution of bennettitalean seed plants during the Mesozoic.

Patterns of cell elongation in the determination of the final shape in galls of Baccharopelma dracunculifoliae (Psyllidae) on Baccharis dracunculifolia DC (Asteraceae)

Cell redifferentiation, division, and elongation are recurrent processes, which occur during gall development, and are dependent on the cellulose microfibrils reorientation. We hypothesized that changes in the microfibrils orientation from non-galled tissues to galled ones occur and determine the final gall shape. This determination is caused by a new tissue zonation, its hyperplasia, and relative cell hypertrophy. The impact of the insect's activity on these patterns of cell development was herein tested in Baccharopelma dracunculifoliae-Baccharis dracunculifolia system. In this system, the microfibrils are oriented perpendicularly to the longest cell axis in elongated cells and randomly in isodiametric ones, either in non-galled or in galled tissues. The isodiametric cells of the abaxial epidermis in non-galled tissues divided and elongated periclinally, forming the outer gall epidermis. The anticlinally elongated cells of the abaxial palisade layer and the isodiametric cells of the spongy parenchyma originated the gall outer cortex with hypertrophied and periclinally elongated cells. The anticlinally elongated cells of the adaxial palisade layer originated the inner cortex with hypertrophied and periclinally elongated cells in young and mature galls and isodiametric cells in senescent galls. The isodiametric cells of the adaxial epidermis elongated periclinally in the inner gall epidermis. The current investigation demonstrates the role of cellulose microfibril reorientation for gall development. Once many factors other than this reorientation act on gall development, it should be interesting to check the possible relationship of the new cell elongation patterns with the pectic composition of the cell walls.

Seasonal and diurnal leaf orientation, bifacial sunlight incidence, and leaf structure in the sand dune herb Hydrocotyle bonariensis

A conceptual model has been proposed whereby leaf orientation and resulting sunlight exposure dictate functional leaf structure. Specifically, the model states that this relationship is driven by the absolute amount and ratio of incident sunlight on adaxial and abaxial leaf surfaces. To test this model, the relationships between corresponding values of leaf orientation and incident sunlight on both leaf surfaces were measured for the sand dune herb Hydrocotyle bonariensis over a growth season, along with examination of leaf structure. For mature leaves, leaf angle from horizontal and azimuth angle significantly increased over the growing season, indicating diurnal midday avoidance and seasonal maximization of incident sunlight. Consequently, seasonal changes in leaf orientation resulted in an overall decrease in midday sunlight incidence on the adaxial surface and a slight shift in the daily occurrence of peak abaxial incidence. Adaxial surfaces received three to four times more sunlight than abaxial surfaces, and leaf cross-sections revealed relatively thick (564 μm) leaves with multiple adaxial palisade layers and stomata on both leaf surfaces, as predicted by the conceptual model and measured ratio of incident sunlight on adaxial and abaxial leaf surfaces. These data provide further evidence of the relationship between leaf orientation and resulting absolute levels of sunlight incidence on both leaf surfaces, as well as their ratio, and corresponding differences in internal and external leaf structure.

Micromorpho-Anatomical Examination of 2,4-D Phytotoxicity in Grapevine (Vitis vinifera L.) Leaves

The anatomical and micro-morphological alterations as induced by the auxinic herbicide, 2,4-D (2,4-dichlorophenoxy acetic acid) have not yet been elucidated for a commercially important fruit crop such as grapevine despite its super sensitivity to 2,4-D. Light and scanning electron microscopy techniques were employed to examine 2,4-D induced internal and external structural abnormalities in Merlot grapevines (Vitis vinifera L.). Healthy leaves were dorsiventrally flattened with well developed patterns of cellular structure and composition involving adaxial palisade parenchyma and abaxial spongy mesophyll. Dorsiventral variations in epidermal features involved large epidermal cells on the adaxial surface, and trichomes and stomata with turgid elliptical guard cells on the abaxial surface. The 2,4-D injured leaves were small and enated; the veins were fasciated with rugose bands of lamina existing between fasciated veins. The epidermal cells aggregated instead of being positioned coplanar to the epidermal plane. The adaxial elongated palisade parenchyma cells were transformed into an ovoid shape with intercellular spaces. An extensive development of replacement tissues took place on the abaxial surface wherein the stomata became roundish and were either raised or sunken with collapsed and cracked guard cells that developed abnormal outer stomatal ledges. These abnormalities are expected to severely perturb the vital functions of photosynthesis and transpiration ultimately leading to vine death attributable, at least in part, to the injured leaves.

Caractérisation histologique de la bractée inflorescentielle de Tilia cordata

Tilia's inflorescence includes a bract which is fused with the base of peduncle. Histology technic was used to investigate Tilia bract. Our studies allow us to see that the vascular system of bract is similar to the vascular system of stem, moreover the lamina part of the bract does not show a adaxial palisade mesophyll; only a spongy mesophyll is present. With a vascular system of stem and in the absence of palisade tissue, we suggest Tilia bract is a cladode structure.

Stomatal crypts may facilitate diffusion of CO2 to adaxial mesophyll cells in thick sclerophylls

In some plants, stomata are exclusively located in epidermal depressions called crypts. It has been argued that crypts function to reduce transpiration; however, the occurrence of crypts in species from both arid and wet environments suggests that crypts may play another role. The genus Banksia was chosen to examine quantitative relationships between crypt morphology and leaf structural and physiological traits to gain insight into the functional significance of crypts. Crypt resistance to water vapour and CO(2) diffusion was calculated by treating crypts as an additional boundary layer partially covering one leaf surface. Gas exchange measurements of polypropylene meshes confirmed the validity of this approach. Stomatal resistance was calculated as leaf resistance minus calculated crypt resistance. Stomata contributed significantly more than crypts to leaf resistance. Crypt depth increased and accounted for an increasing proportion of leaf resistance in species with greater leaf thickness and leaf dry mass per area. All Banksia species examined with leaves thicker than 0.6 mm had their stomata in deep crypts. We propose that crypts function to facilitate CO(2) diffusion from the abaxial surface to adaxial palisade cells in thick leaves. This and other possible functions of stomatal crypts, including a role in water use, are discussed.

Cotyledon areoles in subtribe Kennediinae (Leguminosae: Phaseoleae)

Cotyledon areoles are reported for the first time in Phaseoleae subtribe Kennediinae. All three genera, Kennedia, Hardenbergia and Vandasina, have cotyledon areoles in mature dormant seeds. The remarkably uniform seeds also consistently have an adaxial palisade layer in cotyledons and a greatly expanded middle endosperm layer, which appears to consist primarily of normal legume cell-wall galactomannan.

Anatomical and histochemical defence responses induced in juvenile leaves of Eucalyptus globulus and Eucalyptus nitens by Mycosphaerella infection

SummaryThe responses of juvenile leaves of two Eucalyptus species, with contrasting susceptibility to infection by Mycosphaerella leaf disease, were compared. The anatomical changes, accumulation of phenolics, suberin, lignin and anthocyanin and the retention of chlorophyll were studied in leaf lesions of varying developmental stages caused by species of Mycosphaerella. Enhanced resistance of Eucalyptus nitens in southern Australia was attributed to the formation of an effective lignified and suberized necrophylactic periderm, to restrict pathogen spread. Leaves of E. nitens contained isobilateral palisade which resulted in both abaxial and adaxial cell division and the initiation of a strong reinforced cellular zone from an early lesion stage. Eucalyptus globulus formed a slower, distorted necrophylactic periderm through hypertrophic changes to existing mesophyll and limited cell divisions of the single adaxial palisade layer. Deposits of lignin and suberin did not occur until later in lesion development, which were not effective in preventing further disease development. From this study it is hypothesized that tolerance of eucalypts to Mycosphaerella pathogens may be associated with constitutive mesophyll density.

Integrated control of water hyacinth with a mycoherbicide and a phenylpropanoid pathway inhibitor

The fungus Alternaria eichhorniae isolate 5 (Ae5) is being developed as an effective mycoherbicide against water hyacinth in Egypt. To improve its pathogenicity, integration with 3,4-methylenedioxy trans-cinnamic acid (MDCA), a phenylpropanoid pathway inhibitor that weakens the plant's defense system, was explored. The severity of the disease induced by Ae5 increased when applied to water hyacinth plants pretreated with MDCA. Infection with Ae5 amplified the total phenol concentration in diseased water hyacinth leaves, whereas MDCA reduced it. Plants treated with both Ae5 and MDCA contained a comparable level of total phenols to that in the untreated control plants. Phenol-storing cells were located at three sites in the leaf, within the adaxial palisade tissue, above the abaxial epidermis and in the vicinity of the vascular bundles. Dimensions of these three cell types were increased by infection with Ae5, decreased by MDCA treatment and, in the combined treatment, were similar to those in control leaves. Increased numbers of phenol-storing cells were found only in the region near vascular bundles of plants treated with either Ae5 or MDCA.

Leaf architecture and direction of incident light influence mesophyll fluorescence profiles

Light propagation and distribution inside leaves have been recognized as important processes influencing photosynthesis. Monochromatic light absorption across the mesophyll was measured using chlorophyll fluorescence generated from illumination of the cut edge (epi-illumination), as well as the adaxial or abaxial surfaces of the leaf. Species were selected that had basic leaf types: laminar leaf with adaxial palisade layer (Rhododendron catawbiense), needle with palisade (Abies fraseri), and needle without palisade (Picea rubens). Fluorescence was more evenly distributed across the mesophyll for adaxially illuminated leaves with a palisade cell layer, as well as for the needles (cylindrical) without palisade, when compared to fluorescence generated by abaxial illumination. Moreover, fluorescence from green light illumination remained high across the mesophyll of adaxially illuminated R. catawbiense, indicating a possible influence of mesophyll structure on internal light distribution beyond that of chlorophyll levels. These data support the idea that light propagation within the mesophyll is associated with asymmetric mesophyll structure, in particular the presence of palisade cell layers. In addition, we propose that the evolution of a more cylindrical leaf form, such as found in conifer species, may be a structural solution to excessive sunlight that replaces the highly differentiated mesophyll found in most laminar-leaved species.

Estrutura foliar de espécies de Aechmea Ruiz &amp; Pav. (Bromeliaceae) do Estado de São Paulo, Brasil

O estudo da estrutura foliar de Aechmea bromeliifolia (Rudge) Baker, A. distichantha Lem., A. ornata Baker, A. nudicaulis (L.) Griseb., A. pectinata Baker, A. coelestis (K. Koch) E. Morren, A. cylindrata Lindm. e A. gracilis Lindm. mostrou que, em todas as espécies, as folhas são hipoestomáticas e revestidas por células epidérmicas de paredes sinuosas e portadoras de corpos silicosos. Apresentam também hipoderme mecânica e aqüífera, escamas nas duas superfícies e canais de aeração, interrompidos por diafragmas de células braciformes, no parênquima clorofiliano. A ocorrência restrita de algumas características permitiu elaborar uma chave de identificação para os representantes estudados. Tais características incluem a ocorrência de grupos de fibras extravasculares, de parênquima paliçádico adaxial, de extensão de bainha nos feixes vasculares de menor calibre, de obstrução nas câmaras subestomáticas, além de variação na espessura da hipoderme aqüífera e no número de células que formam o pedículo das escamas.

Ontogenetic differences in mesophyll structure and chlorophyll distribution in Eucalyptus globulus ssp. globulus (Myrtaceae)

Mesophyll structure has been associated with the photosynthetic performance of leaves via the regulation of internal light and CO(2) profiles. Differences in mesophyll structure and chlorophyll distribution within three ontogenetically different leaf types of Eucalyptus globulus ssp. globulus were investigated. Juvenile leaves are blue-grey in color, dorsiventral (adaxial palisade layer only), hypostomatous, and approximately horizontal in orientation. In contrast, adult leaves are dark green in color, isobilateral (adaxial and abaxial palisade), amphistomatous, and nearly vertical in orientation. The transitional leaf type has structural features that appear intermediate between the juvenile and adult leaves. The ratio of mesophyll cell surface area per unit leaf surface area (A(mes)/A) of juvenile leaves was maximum at the base of a single, adaxial palisade layer and declined through the spongy mesophyll. Chlorophyll a + b content showed a coincident pattern, while the chlorophyll a:b ratio declined linearly from the adaxial to abaxial epidermis. In comparison, the mesophyll of adult leaves had a bimodal distribution of A(mes)/A, with maxima occurring beneath both the adaxial and abaxial surfaces within the first layer of multiple palisade layers. The distribution of chlorophyll a + b content had a similar pattern, although the maximum ratio of chlorophyll a:b occurred immediately beneath the adaxial and abaxial epidermis. The matching distributions of A(mes)/A and chlorophyll provide further evidence that mesophyll structure may act to influence photosynthetic performance. These changes in internal leaf structure at different life stages of E. globulus may be an adaptation for increased xeromorphy under increasing light exposure experienced from the seedling to adult tree, similar to the characteristics reported for different species according to sunlight exposure and water availability within their native habitats.

Anatomically preserved leaves of the conifer notophytum krauselii (Podocarpaceae) from the Triassic of Antarctica

Permineralized leaves of the Triassic podocarpaceous conifer Notophytum krauselii are described from the Fremouw Formation of Antarctica. The leaves are elongate and apetiolate with 8-12 parallel veins. The adaxial epidermis consists of rows of rectangular to pentagonal cells; the abaxial epidermis is papillate. Longitudinally oriented stomata occur on both surfaces. An adaxial palisade layer is present and auxiliary sclereids are common in the mesophyll. The vascular bundles have a weakly defined sheath and are flanked by transfusion tracheids. Bundles in the basipetal area of the leaf are capped by sclerotic tissue and subtended by resin canals. These leaves are superficially similar to those of the extant podocarp genus Nageia, but probably represent a distinct acquisition of this leaf type within the Podocarpaceae. Notophytum leaves are similar to the common compression fossil Heidiphyllum elongatum and may be closely related or even conspecific. Evidence from Antarctica suggests that Heidiphyllum and the seed cone Telemachus were produced by the same plant, and may be closely related to several other early Mesozoic conifers with multiveined leaves.

Morphology and Anatomy of Leaves of Eucalyptus camaldulensis Clones: Variation Between Geographically Separated Locations

Leaves of six clonal individuals of Eucalyptus camaldulensis Dehnh. from five Australian locations were compared. Two clones were from Wooramel, WA while single clonal lines were from Dongara, WA, Erudina, SA, Murray Bridge, SA and Silverton, NSW. Principal component analysis of climatic factors for the five locations, derived by BIOCLIM, provided patterns of temperature, radiation and atmospheric moisture, which might be expected to influence the morphological and anatomical features of the leaves. Isozyme analysis indicated that the two Wooramel clones were closely related, but comparable similarity in isozyme pattern was also found between a Wooramel clone and the representative from Murray Bridge. Leaf morphological and anatomical features showed patterns related to the habitat climate of the parent plants, but considerable genetic variation was observable even within a single location. Leaf thickness was generally greatest for clones from the more arid locations and least for clones from the most mesic of locations, but leaf length and width were not associated with any of the climatic factors considered. Thin leaf cuticles were associated with thin leaves. Leaf thickness was determined by the thickness of the internal cell layers, as all clones contained an epidermal and three palisade parenchyma cell layers on both adaxial and abaxial sides. Adaxial palisade layers were thicker than abaxial palisade layers. Stomatal density was not related to leaf dimensions, but clones with the greatest stomatal density tended to have the smallest stomatal pore dimensions. Oil gland density was greatest for leaves of Western Australian clones. Clones from the more arid locations displayed larger chloroplasts. In general, there was a lack of correlation between leaf characteristics and climatic data. Ground water availability, root structure and internal transport of water may have a greater influence on leaf structure than atmospheric demand.