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1.
Teucrium montanum L. and T. polium L. are the two closest Teucrium L. species from sect. Polium (Mill.) Schreb in Turkey. In addition, they are sympatric for some part of their range in Turkey. In this study, comparative anatomical and micromorphological studies of the two species are carried out. They have been investigated by their leaf and stem anatomical features, as well as nutlet micromorphological characteristics. The results of anatomical studies show that the anatomical characters of both taxa are observed to be similar to the general features of the family Lamiaceae anatomy, except for lacking rich collenchyma at the corners. Both taxa are similar in stem anatomy and their leaves exhibit xeromorphy. However, trichome morphology on the stems and the leaves appear to have a taxonomic value in segregation of the two taxa. Light and scanning electron microscope studies on the nutlets also show that nutlet shapes, measures and surface micromorphologies are different in the two species. Whereas nutlet surfaces are bireticulate in both species, the nutlets are larger and primary sculpturing is more distinct in T. polium than in T. montanum. Moreover, the nutlets are oblong to oblong-ovoid and larger in T. polium, but ovoid and smaller in T. montanum.  相似文献   

2.
Nitraria retusa and Atriplex halimus (xero-halophytes) plants were grown in the range 0–800 mM NaCl while Medicago arborea (glycophyte) in 0–300 mM NaCl. Plants were harvested after 120 days of salt-treatment. The present study was designed to study the effect of salinity on root, stem and leaf anatomy, water relationship, and plant growth in greenhouse conditions. Salinity induced anatomical changes in the roots, stems and leaves. The cuticle and epidermis of N. retusa and A. halimus stems were unaffected by salinity. However, root anatomical parameters (root cross section area, cortex thickness and stele to root area ratio), and stem anatomical parameters (stem cross section area and cortex area) were promoted at 100–200 mM NaCl. Indicating that low to moderate salinity had a stimulating effect on root and stem growth of these xero-halophytic species. At higher salinities, root and stem structures were altered significantly, and their percentages of reduction were higher in A. halimus than in N. retusa whereas, in M. arborea, they were strongly altered as salinity rose. NaCl (100–300 mM) reduced leaf water content by 21.2–56.2% and specific leaf area by 51–88.1%, while increased leaf anatomical parameters in M. arborea (e.g. increased thickness of upper and lower epidermis, palisade and spongy mesophyll, entire lamina, and increased palisade to spongy mesophyll ratio). Similar results were evidenced in A. halimus leaves with salinity exceeding 100 mM NaCl. Leaves of N. retusa were thinner in salt-stressed plants while epidermis thickness and water content was unaffected by salinity. The size of xylem vessel was unchanged under salinity in the leaf’s main vein of the three species while we have increased number in M. arborea leaf main vein in the range of 200–300 mM NaCl. A longer distance between leaf vascular bundle, a reduced size and increased number of xylem vessel especially in stem than in root vascular system was evidenced in M. arborea treated plants and only at (400–800 mM) in the xero-halophytic species. The effects of NaCl toxicity on leaf, stem and root ultrastructure are discussed in relation to the degree of salt resistance of these three species. Our results suggest that both N. retusa and A. halimus show high tolerance to salinity while M. arborea was considered as a salt tolerant species.  相似文献   

3.
The elucidation of molecular mechanisms underlying the leaf development can be facilitated by the detailed anatomical study of leaf development mutants. We present an analysis of leaf anatomy and morphogenesis during early developmental stages in has mutant of Arabidopsis thaliana. The recessive has mutation affects a number of aspects in plant development, including the shape and size of both cotyledons and leaves. The earliest developmental observations suggest almost synchronous growth of the first two leaf primordia of has mutant. No significant disruption of the cell division pattern in the internal tissue is observed at the earliest stages of development, with the major anatomical difference compared to wild type primordia being the untimely maturation of mesophyll tissue cells in has mutant. At the stage of leaf blade formation, structure disruption becomes clearly evident, by irregular arrangement of the cell layers and the lack of polarity in juvenile has leaves. One distinguishing feature of the mutant leaf anatomy is the absence of mesophyll tissue differentiation. Altered has mutant leaf morphology could be at least partially accounted for by the ectopic STM activity that was found at the base of leaf primordia during early stages of leaf development in has plants.  相似文献   

4.
In this study, the morphological and anatomical features of endemic Lamium moschatum Miller var. rhodium (Gand.) R. Mill (Lamiaceae) are described in detail. Lamium moschatum var. rhodium has an annual taproot. The stem is erect and clearly quadrangular. The leaves are broadly ovate to cordate-ovate or nearly suborbicular in shape. Inflorescense is verticillate cyme. The corolla is white and the tube is curved and bears an annulus inside, near the base. Cross-sections of the root, stem, petiole, leaf, calyx, corolla and generative organs were examined and the anatomical features of the taxon are discussed. Furthermore, glandular hairs distributed on the plant taxon are shown. In karyological research, chromosome numbers were determined as 2n = 18. The results are presented with photographs and tables.  相似文献   

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6.
The root anatomy of the subalpine to alpine plant species Saussurea discolor (Willd.) DC., and Saussurea pygmaea (Jacq.) Spreng., (Asteraceae) has been investigated by means of light and fluorescence microscopy on specimens of Austrian provenance. Both species develop a so called interxylary cork which mediates the splitting of the root into various strands. This phenomenon takes place in the secondary xylem and involves the development of a periderm separating the originally solid xylem cylinder. Interxylary cork is currently known from approximately 40 species of the Dicotyledones. This is the first report of this specific anatomical structure from the two studied species.  相似文献   

7.
The relative importance that biomechanical and biochemical leaf traits have on photosynthetic capacity would depend on a complex interaction of internal architecture and physiological differences. Changes in photosynthetic capacity on a leaf area basis and anatomical properties during leaf development were studied in a deciduous tree, Prunus persica, and an evergreen shrub, Olea europaea. Photosynthetic capacity increased as leaves approached full expansion. Internal CO2 transfer conductance (g i) correlated with photosynthetic capacity, although, differences between species were only partially explained through structural and anatomical traits of leaves. Expanding leaves preserved a close functional balance in the allocation of resources of photosynthetic component processes. Stomata developed more rapidly in olive than in peach. Mesophyll thickness doubled from initial through final stages of development when it was twice as thick in olive as in peach. The surface area of mesophyll cells exposed to intercellular air spaces per unit leaf area tended to decrease with increasing leaf expansion, whereas, the fraction of mesophyll volume occupied by the intercellular air spaces increased strongly. In the sclerophyllous olive, structural protection of mesophyll cells had priority over efficiency of photochemical mechanisms with respect to the broad-leaved peach. The photosynthetic capacity of these woody plants during leaf development relied greatly on mesophyll properties, more than on leaf mass per area ratio (LMA) or nitrogen (N) allocation. Age-dependent changes in diffusion conductance and photosynthetic capacity affected photosynthetic relationships of peach versus olive foliage, evergreen leaves maturing functionally and structurally a bit earlier than deciduous leaves in the course of adaptation for xeromorphy.  相似文献   

8.
Paphiopedilum and Cypripedium are closely related in phylogeny, but have contrasting leaf traits and habitats. To understand the divergence in leaf traits of Paphiopedilum and Cypripedium and their adaptive significance, we analyzed the leaf anatomical structures, leaf dry mass per area (LMA), leaf lifespan (LL), leaf nitrogen concentration (N mass), leaf phosphorus concentration (P mass), mass-based light-saturated photosynthetic rate (A mass), water use efficiency (WUE), photosynthetic nitrogen use efficiency (PNUE) and leaf construction cost (CC) for six species. Compared with Cypripedium, Paphiopedilum was characterized by drought tolerance derived from its leaf anatomical structures, including fleshy leaves, thick surface cuticles, huge adaxial epidermis cells, lower total stoma area, and sunken stomata. The special leaf structures of Paphiopedilum were accompanied by longer LL; higher LMA, WUE, and CC; and lower N mass, P mass, A mass, and PNUE compared with Cypripedium. Leaf traits in Paphiopedilum helped it adapt to arid and nutrient-poor karst habitats. However, the leaf traits of Cypripedium reflect adaptations to an environment characterized by rich soil, abundant soil water, and significant seasonal fluctuations in temperature and precipitation. The present results contribute to our understanding of the divergent adaptation of leaf traits in slipper orchids, which is beneficial for the conservation of endangered orchids.  相似文献   

9.
A comparative study of leaf architecture and anatomy of 42 species of Bernardia and other genera related of Acalyphoideae was undertaken to identify characters that support infrageneric and specific delimitation. Thirty variable foliar architectural and anatomical characters were studied. Some characters are consistent (e.g., venation pattern, secondary and tertiary vein arrangement, presence or absence of agrophic veins, type of areoles, bundle sheath cell type, presence or absence of fibers in the mesophyll, trichome type, stomata location, and type of crystals), and characterize genera. In addition, foliar character distribution within Bernardia supports the most recent infrageneric classification.  相似文献   

10.
This study investigates responses in the leaf anatomy of Black Locust (Robinia pseudoacacia L.) to the atmospheric pollutants, SO2, NO2 and O3 and climate in Tehran. The anatomical variables studied include thickness of the leaf lamina and of its main constituent tissues and the length and density of stomata. We present evidence that, in response to urban air pollution, the spongy mesophyll layer is thinner, the upper cuticle of the leaf thicker and stomatal density and the ratio of palisade parenchyma to spongy parenchyma are increased. Similar responses were also detected in relation to a climatic gradient. Stomatal density and thickness of the leaf lamina and of its mesophyll layer were all higher under warmer drier conditions. This overlap in anatomical response to two very different suites of environmental variables may reflect a functional overlap between mechanisms designed to restrict water loss in dry climates and those that minimize the uptake of toxic gases in polluted habitats.  相似文献   

11.
In this study, the anatomical features of the leaf and stem, besides the nutlet characteristics of some Teucrium sect. Isotriodon (Lamiaceae) taxa in Turkey, T. montbretii Betham subsp. montbretii, T. montbretii subsp. pamphylicum P. H. Davis, T. odontites Boiss. &; Bal., T. cavernarum P. H. Davis, T. antitauricum T. Ekim, along with an isolated population of T. montbretii (T. montbretii subsp.) were investigated. The anatomical studies revealed that the taxa share generally similar anatomical characters, such as thicker upper leaf cuticles and larger upper leaf epidermal cells compared to lower ones and diacytic to anomocytic stomata on the leaves. However, the portion of the mesophyll occupied by palisade parenchyma and the occurrence of mucilage cells in leaf epidermis shows difference among the taxa. Furthermore, the studied taxa have general stem characteristics of the Lamiaceae family, except for having poorly developed collenchyma at the corners. With the amphistomatic leaves and developed sclerenchymatic tissue in the leaf median vein, T. cavernarum is seperated from the other taxa. Trichome types on the vegetative organs and nutlet shape and sculpturing are generally the same or similar in the studied taxa, but trichomes on the nutlets are different among them. Based on nutlet characteristics and some morphological ones, it was revealed that the isolated population of T. montbretii represent a new subspecies, T. monbretii subsp. yildirimlii M.Dinç &; S.Do?u subsp. nov.  相似文献   

12.
Petra Hoffmann 《Brittonia》2008,60(2):136-166
Heterosavia (Phyllanthaceae) is segregated from Savia (tribe Bridelieae), recognized at generic rank, and placed in tribe Phyllantheae. Floral, fruit, leaf anatomical, leaf venation, and pollen characters of the neotropical taxa previously united as Savia including Gonatogyne are discussed and illustrated. Keys to the three genera and to the species of Heterosavia are presented. Four species (all new combinations), Heterosavia bahamensis, H. erythroxyloides, H. laurifolia, and H. maculata, are recognized. The new combinations Heterosavia laurifolia var. intermedia and H. maculata var. clementis are proposed. The names Heterosavia, H. erythroxyloides, H. laurifolia, Savia clementis, S. clusiifolia, S. clusiifolia var. fallax, and S. longipes are lectotypified. Distribution maps and conservation assessments (IUCN ratings) of Heterosavia species and varieties are provided.  相似文献   

13.
Two taxa of the genus Pluteus, i.e., Pluteus magnus and Pluteus podospileus f. podospileus, are newly recorded from Japan. The macroscopic and microscopic features of these two species are described and illustrated.  相似文献   

14.
The cross compatible wild relatives of crops have furnished valuable genes for crop improvement. Understanding the genetics of these wild species may enhance their further use in breeding. In this study, sequence variation of the nuclear Lhs1 gene was used to investigate the population genetic structure and gene flow of Oryza rufipogon and O. nivara, two wild species most closely related to O. sativa. The two species diverge markedly in life history and mating system, with O. rufipogon being perennial and outcrossing and O. nivara being annual and predominantly inbreeding. Based on sequence data from 105 plants representing 11 wild populations covering the entire geographic range of these wild species, we detected significantly higher nucleotide variation in O. rufipogon than in O. nivara at both the population and species levels. At the population level the diversity in O. rufipogon (Hd = 0.712; θ sil = 0.0017) is 2–3 folds higher than that in O. nivara (Hd = 0.306; θ sil = 0.0005). AMOVA partitioning indicated that genetic differentiation among O. nivara populations (78.2%) was much higher than that among O. rufipogon populations (52.3%). The different level of genetic diversity and contrasting population genetic structure between O. rufipogon and O. nivara might be explained by their distinct life histories and mating systems. Our simulation using IM models demonstrated significant gene flow from O. nivara to O. rufipogon, indicating a directional introgression from the annual and selfing species into the perennial and outcrossing species. The ongoing introgression has played an important role in shaping current patterns of genetic diversity of these two wild species. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

15.
The anatomical research of the vegetative organs of the cytoplasmatic hybrid grown in vitro and containing the Brassica napus nucleus and the Lesquerella fendleri chloroplasts was carried out and compared to the parental forms. It was found that the anatomical structure of the cybrid is similar to rapeseed. Anomalous changes in the epithelial, parenchymal, and connective tissue of the leaf, stalk, stem, and root of the cybrid were detected. The appearance of the anatomical defects can be explained by nuclear-cytoplasmatic incompatibility, which is the cause of low adaptability of the cybrid to in vivo conditions and takes place due to alien chloroplast gene expression in the remote species.  相似文献   

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18.
A comparative study of Taxodium distichum (L.) Rich. and Taxodium mucronatum Ten. was carried out on the basis of pollen morphology and wood anatomy by light and scanning electron microscopy. We describe a detailed analysis of the anatomical characteristics of the wood, including the tracheids, ray parenchyma, axial parenchyma and number of cross-field pits. Palynological characters were also studied to reveal the shape, size and ultrastructure of the pollen grains. These studies give taxonomic support for the recognition of T. distichum and T. mucronatum as two different species.  相似文献   

19.
20.
Fecundity and feeding of two introduced sibling biological control species, Galerucella calmariensis and G. pusilla (Coleoptera: Chrysomelidae) on purple loosestrife, Lythrum salicaria L. (Lythraceae) were compared at constant temperatures of 12.5, 15, 20, 25, and 27.5 °C. Larval feeding was also carried out at 30 °C, but at this temperature, larvae developed only to the L2 stage and none pupated. Thus, data for this temperature were not used in the analysis. There were significant species × temperature interactions in fecundity. Of the two species, Galerucella pusilla laid more eggs. Although egg production of both species was lowest at 12.5 °C and increased to 20 °C, at higher temperatures, the two species reacted differently. From 25 to 27.5 °C, egg production decreased for G. pusilla, but G. calmariensis fecundity peaked at 27.5 °C. Significant temperature × species × life-stage interactions were also observed in feeding. For each species, the amount of feeding varied with temperature and stage of development. Galerucella pusilla adults consumed more foliage at 15, 20, and 27.5 °C. However, at 12.5 °C G. calmariensis adults fed more than G. pusilla. G. pusilla larvae consumed an average of 25% less foliage than G. calmariensis. The lower larval consumption of G. pusilla suggests that when food is limited, G. pusilla larvae may have a higher survival rate because of its ability to complete larval development with less food and produce more progeny due to its greater fecundity. When food is not limited neither species would have a competitive advantage and both species could coexist temporally and spatially. However, since G. calmariensis larvae consumed more leaf material, the larval stage of this species would have a greater impact on purple loosestrife than G. pusilla.  相似文献   

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