Early stages of initiation of two types of leaves in Thuja occidentalis (eastern white cedar)

2004 ◽  
Vol 82 (5) ◽  
pp. 598-606 ◽  
Author(s):  
Christian Lacroix ◽  
Denis Barabé ◽  
Bernard Jeune
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Apical Meristem ◽  
Leaf Primordia ◽  
Leaf Primordium ◽  
Thuja Occidentalis ◽  
White Cedar ◽  
Early Stages ◽  
Eastern White Cedar ◽  
Scanning Electron

The developmental morphology of shoots of Thuja occidentalis L. (eastern white cedar) was investigated using scanning electron microscopy to determine the pattern of initiation of two types of leaves characteristic of higher (third and above) order branches. The shoots of eastern white cedar are bilateral in symmetry and bear leaves in an orthogonal decussate phyllotactic pattern. The shoot system is further characterized by the presence of two alternating and morphologically different pairs of leaves that constitute the basic repeating pattern of the shoot apical meristem (SAM). At maturity the dimorphism between leaf types is marked. Leaves in one plane are wide and flat in comparison with narrower and cup-shaped leaves growing in a plane perpendicular to the other leaf type. The early stages of development of each of the two types of leaves were compared using scanning electron microscopy. During the earliest visible stages of initiation (primordial crest), cup-shaped and flat leaves are very similar in morphology. As individual leaf primordia become more easily delimited as structures by the presence of a furrow between the SAM and the leaf, they differ in terms of width. As they develop further and begin to cover the SAM, the two leaf types are distinguishable morphologically (flat vs. cup shaped). Quantitative parameters such as diameter of the SAM, angle of insertion of individual leaves, and size of leaf primordia (in both a tangential and perpendicular plane) were measured on three categories of leaves: stage 1, earliest visible stage of initiation; stage 2, delineation of leaf primordium from SAM by furrowing; stage 3, leaf primordium partially covering SAM. These measurements corroborate our morphological observations, which show that during early stages of development, flat and cup-shaped leaves are morphologically similar and they diverge in their pattern of development postinitiation, especially as far as leaf width and thickness are concerned. Our results also suggest that the size and shape of the apex goes through a "repeating" cycle and is related to the type of primordium that will be initiated.Key words: Thuja occidentalis, eastern white cedar, leaf development, shoot apical meristem, phyllotaxy, leaf dimorphism.

scholarly journals Morphological characterization of domatium development in Callicarpa saccata

2019 ◽  
Vol 125 (3) ◽  
pp. 521-532
Author(s):  
Emma Sarath ◽  
Kazune Ezaki ◽  
Takenori Sasaki ◽  
Yu Maekawa ◽  
Yuji Sawada ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Proliferation ◽  
Morphological Characterization ◽  
Leaf Primordia ◽  
Normal Functioning ◽  
Simple Leaf ◽  
Mesophyll Tissue ◽  
Scanning Electron

Abstract Background and aims Domatia are plant structures within which organisms reside. Callicarpa saccata (Lamiaceae) is the sole myrmecophyte, or ‘ant plant’, that develops foliar (leaf-borne) myrmeco-domatia in this genus. In this work we examined domatium development in C. saccata to understand the developmental processes behind pouch-like domatia. Methods Scanning electron microscopy, sectioning and microcomputed tomography were carried out to compare the leaves of C. saccata with those of the closely related but domatia-less myrmecophyte Callicarpa subaequalis, both under cultivation without ants. Key results Callicarpa saccata domatia are formed as a result of excess cell proliferation at the blade/petiole junctions of leaf primordia. Blade/petiole junctions are important meristematic sites in simple leaf organogenesis. We also found that the mesophyll tissue of domatia does not clearly differentiate into palisade and spongy layers. Conclusions Rather than curling of the leaf margins, a perturbation of the normal functioning of the blade/petiole junction results in the formation of domatium tissue. Excess cell proliferation warps the shape of the blade and disturbs the development of the proximal–distal axis. This process leads to the generation of distinct structures that facilitate interaction between C. saccata and ants.

Developmental morphology of the flower of Anthurium jenmanii: a new element in our understanding of basal Araceae

Botany ◽  
2008 ◽  
Vol 86 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Denis Barabé ◽  
Christian Lacroix
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Floral Development ◽  
Developmental Morphology ◽  
Calcium Oxalate Crystals ◽  
Stages Of Development ◽  
Early Stages ◽  
Floral Primordia ◽  
Scanning Electron

The early stages of development of the inflorescence of Anthurium jenmanii Engl. were examined using scanning electron microscopy. The inflorescence of A. jenmanii consists of more than 100 flowers arranged in recognizable spirals. Each flower has four broad tepals enclosing four stamens that are not visible prior to anthesis. The gynoecium consists of two carpels. The floral primordia are first initiated on the lower portion of the inflorescence, they then increase in size and appear as transversely extended bulges. The two lateral tepals are the first organs to be initiated, followed shortly thereafter by the two median tepals. The two lateral stamens are initiated first, directly opposite the lateral tepals, and are followed by two median stamens initiated directly opposite the median tepals. A two-lobed stigma is clearly visible during the early stages of development of the gynoecium. On some of the young inflorescences, all floral parts were covered by extracellular calcium oxalate crystals. The release of these prismatic crystals occurs before the stamens and petals have reached maturity. The mode of floral development observed in Anthurium has similarities with that reported for Gymnostachys . However, contrary to Gymnostachys, the development of the flower of A. jenmanii is not unidirectional.

scholarly journals Architectural Development of Inflorescence in Hydrangea macrophylla cv. Hermann Dienemann

HortScience ◽  
2008 ◽  
Vol 43 (2) ◽  
pp. 361-365 ◽  
Author(s):  
Gilles Galopin ◽  
Sandrine Codarin ◽  
Jean-Daniel Viemont ◽  
Philippe Morel
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Inflorescence Development ◽  
Schematic Representation ◽  
Early Stages ◽  
Hydrangea Macrophylla ◽  
Floral Differentiation ◽  
Architectural Development ◽  
Scanning Electron

Architectural development of inflorescence in Hydrangea macrophylla cv. Hermann Dienemann was observed using scanning electron microscopy. The study of inflorescence morphogenesis shows that the architecture is of the dichasial type. The first two orders of branching are initiated from a dichasial branching without floral differentiation. The following orders present floral differentiation. They determine the formation of small units through the development of composite dichasium into biparous and uniparous cymes. This research makes it possible to establish a schematic representation of the first phases of inflorescence development and to define early stages of inflorescence morphogenesis.

scholarly journals New registers of colleters in species of Myrtaceae from Brazilian Cerrado

Rodriguésia ◽  
2019 ◽  
Vol 70 ◽  
Author(s):  
Cleber José da Silva ◽  
João Paulo Oliveira Ribeiro ◽  
Renata Maria Strozi Alves Meira
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Fleshy Fruit ◽  
Brazilian Cerrado ◽  
Secretory Structures ◽  
Histochemical Tests ◽  
Potential Use ◽  
Scanning Electron

Abstract Colleters are secretory structures that produce a sticky substance, consisting of a mixture of mucilage, proteins, terpenes, pectic substances and even alkaloids, which lubricates and protects the shoot apical meristem. Several colleter types have been described and have taxonomic value in many botanical families. In Myrtaceae, the colleters description is recent and presents three new morphological types (conic, euryform and petaloid) that differ those already described for other eudicots. In this work, we report the colleters morphological types in six species of three genera belonging to the Myrteae tribe of Myrtoideae from the Brazilian Cerrado. The samples were fixed for light and scanning electron microscopy. Histochemical tests were carried out on the fresh and methacrylate-embedded material. The conic and euryform colleters from Myrtoideae species of the Cerrado did not differ either morphologically nor as to the secretion nature from those described for Myrtoideae species from others biomes, which may indicate their potential use for taxonomic purposes. Considering the hypothesis that the multiple fleshy-fruit lineages have evolved independently in Myrteae tribe, our results indicate the relevance of additional studies in order to recognize the pattern of distribution of colleters in Myrtaceae.

Comparison of Scanning Electron Microscopy and Light Microscopy for the Diagnosis of Early Stages of Brown Rot Wood Decay

IAWA Journal ◽  
1993 ◽  
Vol 14 (3) ◽  
pp. 219-226 ◽  
Author(s):  
W. Wayne Wilcox
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Cell Walls ◽  
Wood Decay ◽  
Brown Rot ◽  
Early Stages ◽  
Polarised Light ◽  
Scanning Electron

As part of a larger study of the microscopical characteristics useful in diagnosing early stages of decay, an opportunity was created to compare the ability of light microscopy (LM) and scanning electron microscopy (SEM) to image these features. Although most features could be imaged by both technologies, imaging was much easier in the SEM because it was being used at the low end of its resolution and magnification capability while the LM was near the high end of its limitations. One important feature which could not be imaged in SEM was the earliest attack on the cell walls, a feature which was visible under polarised light in the LM.

scholarly journals Enhancement of Growth and Flowering of Triteleia laxa by Ethylene

1990 ◽  
Vol 115 (3) ◽  
pp. 482-486 ◽  
Author(s):  
Susan S. Han ◽  
Abraham H. Halevy ◽  
Roy M. Sachs ◽  
Michael S. Reid
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Growth Rate ◽  
Respiration Rate ◽  
Apical Meristem ◽  
Day Treatment ◽  
Fresh Weight ◽  
Final Size ◽  
Meristem Size ◽  
Scanning Electron

Exposure of dormant corms of Triteleia laxa `Queen Fabiola' to 20 ppm C2H4 for 7 days promoted flowering of small corms and resulted in increased apical meristem size, early sprouting, early flowering, more flowers per Inflorescence, and increased fresh weight of daughter corms and cormels. The respiration rate of the C&treated corms increased to four to five times that of the controls during the 7-day treatment, declined markedly after termination of the C2H4 treatment, but remained higher than that of the controls. The C2H4 effects were associated with increased growth rate and consequently a greater final size of the apical meristem (determined by scanning electron microscopy). Leaves produced by C2H4-treated corms were wider, longer, and weighed more than those of the controls.

Complex tendril branching in two species of Parthenocissus: implications for the vitaceous shoot architecture

2003 ◽  
Vol 81 (6) ◽  
pp. 587-597 ◽  
Author(s):  
Trevor Wilson ◽  
Usher Posluszny
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Apical Meristem ◽  
Lateral Growth ◽  
Developmental Morphology ◽  
Main Shoot ◽  
Lateral Buds ◽  
Shoot Architecture ◽  
Parthenocissus Quinquefolia ◽  
Scanning Electron

This study compares the developmental morphology of Parthenocissus quinquefolia Planch. (L.) (Virginia creeper) with that of Parthenocissus tricuspidata (Sieb. & Zucc.) Planch. (Boston ivy) to better understand how the tendril is related to the main shoot architecture of the Vitaceae. Tendril development is looked at from inception to maturity using scanning electron microscopy and epi-illumination microscopy. A tendril primordium is initiated low on the periphery of a shoot apical meristem; this pattern of development is reminiscent of typical monopodial shoot development. A tendril "shoot" in turn produces several bract-opposed branches and resembles the main shoot in its early development. However, a tendril develops through lateral growth, and because it lacks lateral buds, its architecture appears more sympodial than the main shoot. As more tendril branches are produced, the tendril "shoot" pattern of development gradually changes to a pattern of development reported in other vitaceous tendrils. This shift in development suggests how other vitaceous tendrils may be related to the shoot. Because tendril development in Parthenocissus can be demonstrated to be sympodial, it lends evidence to the idea that the unique monopodial-like system in members of the Vitaceae may be derived. The main shoot and tendril development are more similar than has previously been shown.Key words: Vitaceae, Parthenocissus, monopodial, sympodial, tendril, development.

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