scholarly journals Cytological Examination of Scilla peruviana L. during a 20-month Cycle of Growth and Development

HortScience ◽  
1998 ◽  
Vol 33 (7) ◽  
pp. 1175-1179 ◽  
Author(s):  
Naza Sh. Azizbekova ◽  
Stefanie L. Butland ◽  
Brian E. Ellis ◽  
Christia M. Roberts
Keyword(s):  
Growth And Development ◽  
Apical Meristem ◽  
Cytological Study ◽  
Growth Cycle ◽  
Flower Initiation ◽  
Cytological Examination ◽  
Complete Cycle ◽  
Meristematic Cells ◽  
Two Generations ◽  
Floral Differentiation

The growth cycle of Scilla peruviana L. involved the development of two generations of daughter bulbs enclosed within each mother bulb. Flower initiation of the primary daughter bulb took place in June as the mother bulb apparently entered dormancy. Floral differentiation was complete by late October, by which time the apical meristem of the secondary daughter bulb had developed for 3 months inside the primary daughter bulb. The complete cycle of ontogenesis, from meristem initiation to flowering, occurred without interruption and required 20 months. Small zones of meristematic cells detected at the bases of bulb scales may be the origin of adventitious bulblets in this species. This detailed cytological study enabled the development of an effective commercial forcing program for S. peruviana.

scholarly journals Annual Growth and Development of Scilla peruviana

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 467B-467
Author(s):  
Naza Azizbekova ◽  
Christia M. Roberts ◽  
Stefanie Butland ◽  
Brian Ellis
Keyword(s):  
Growth And Development ◽  
Apical Meristem ◽  
Rest Period ◽  
Annual Growth ◽  
Multiplication Rate ◽  
Vegetative Development ◽  
Organ Differentiation ◽  
Two Generations ◽  
Bulbous Plant ◽  
Temperature And Growth

Scilla peruviana is a bulbous plant whose distribution extends from South Africa, into Europe and Asia. It belongs to the family Liliaceae (subclass Monocotyledonae). S. peruviana is an attractive floral species with excellent commercial potential, but it does not produce many bulblets and its multiplication rate is very low. Increasing the multiplication rate, and regulation of its growth and development, cannot be achieved without knowledge of its basic patterns of ontogenesis. We studied the annual growth and development of S. peruviana, from initiation until differentiation, giving special attention to cytological changes at the apical meristem. We also investigated the cytophysiological changes occurring in scales during ontogenesis. Two generations of daughter bulbs are present in each mother bulb. Flowering of the mother bulb coincides with vegetative development of the apical meristem of the primary daughter bulb (March-April). During gradual senescence of leaves and roots of the mother bulb, the apical meristem of the primary daughter bulb undergoes a transition from vegetative to prefloral development (June). Intensive flower organ differentiation occurs in the daughter bulb during the mother bulb's rest period (July–August). Initiation of the apical meristem of the secondary daughter bulb occurs within the primary daughter bulb, which is itself enclosed within the mother bulb (August). The development of the apical meristem of a daughter bulb, from its initiation until flowering, thus occurs without interruption and takes ≈20 months. By modifying external factors such as temperature and growth regulators, we can now control time of flowering and increase the multiplication rate of S. peruviana.

SEM study of the morphological effects of kinetin and zeatin on the growth and development of the apical meristem in wheat

1995 ◽  
Vol 53 ◽  
pp. 978-979
Author(s):  
G. M. Hutchins ◽  
J. S. Gardner
Keyword(s):  
Growth And Development ◽  
Furfuryl Alcohol ◽  
Apical Meristem ◽  
Plant Cells ◽  
Triticum Aestivum L ◽  
Morphological Development ◽  
Naturally Occurring ◽  
Chinese Spring Wheat ◽  
Sem Study ◽  
Moist Environment

Cytokinins are plant hormones that play a large and incompletely understood role in the life-cycle of plants. The goal of this study was to determine what roles cytokinins play in the morphological development of wheat. To achieve any real success in altering the development and growth of wheat, the cytokinins must be applied directly to the apical meristem, or spike of the plant. It is in this region that the plant cells are actively undergoing mitosis. Kinetin and Zeatin were the two cytokinins chosen for this experiment. Kinetin is an artificial hormone that was originally extracted from old or heated DNA. Kinetin is easily made from the reaction of adenine and furfuryl alcohol. Zeatin is a naturally occurring hormone found in corn, wheat, and many other plants.Chinese Spring Wheat (Triticum aestivum L.) was used for this experiment. Prior to planting, the seeds were germinated in a moist environment for 72 hours.

CYTOLOGICAL AND IMMUNOCYTOCHEMICAL DIAGNOSIS OF TUMOR PLEURITIS

2017 ◽  
Vol 63 (6) ◽  
pp. 894-899
Author(s):  
Viktor Novik ◽  
A. Nefedova ◽  
Ye. Yakubo ◽  
O. Ivanov ◽  
Yekaterina Shalina ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Malignant Tumor ◽  
Cytological Study ◽  
False Negative ◽  
Unknown Primary ◽  
Cytological Examination ◽  
Immunocytochemical Studies ◽  
Negative Conclusion ◽  
Primary Localization

Cytological examination of smears from the sediment after centrifugation of pleural fluids was performed in 479 patients who underwent examination and treatment at our institution in 2014-2016. In 249 (52%) patients tumor cells were not detected in smears, in 230 (48%) observations a suspicion (28 observations) or a confident conclusion (202 observations) on the presence of malignant tumor cells in the exudates was cytologically expressed. In 38 cases immunocytochemical studies was additionally performed. In two observations a false-negative conclusion about the absence of tumor cells in smears was expressed. The sensitivity of the cytological study in the diagnosis of malignant pleuritis was 99.0%. Affirmative cytological conclusions on the presence of malignant pleuritis were given in 87.0% of observations, suspicious cytological responses - in 12.0% of cases. Immunocytochemical studies significantly expanded the possibilities of cytological research and were of great importance in the diagnosis of metastases of tumors of unknown primary localization.

scholarly journals RNA-seq analysis of an apical meristem time series reveals a critical point in Arabidopsis thaliana flower initiation

BMC Genomics ◽  
2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Anna V. Klepikova ◽  
Maria D. Logacheva ◽  
Sergey E. Dmitriev ◽  
Aleksey A. Penin
Keyword(s):  
Time Series ◽  
Arabidopsis Thaliana ◽  
Critical Point ◽  
Apical Meristem ◽  
Flower Initiation ◽  
Rna Seq

GROWTH AND DEVELOPMENT OF THE LOWBUSH BLUEBERRY: APICAL ABORTION

1963 ◽  
Vol 41 (9) ◽  
pp. 1319-1324 ◽  
Author(s):  
W. G. Barker ◽  
W. B. Collins
Keyword(s):  
Vegetative Growth ◽  
Growth And Development ◽  
Apical Meristem ◽  
Shoot Growth ◽  
Strong Indication ◽  
Vegetative Tissue ◽  
Aerial Shoot ◽  
Lowbush Blueberry ◽  
Below Ground ◽  
High Level

The semicultivated lowbush blueberry is fire-pruned on a 3- to 4-year cycle. In spring, vegetative growth is accomplished through the development of an axillary bud on an aerial shoot. In a fire-pruned area, the growth is delayed in both its initiation and termination by as much as a month and arises either from axillary buds on the unburned below-ground portions of the aerial stems, or from rhizome seated buds. Shoot growth is terminated by the abortion of the apical meristem and the death of the proximal portions of the axis. Evidence is presented suggesting that the death of the apex is not triggered by an appropriate photoperiod. Further, although it is inherently controlled, it does not follow the production of a specified quantity (relative to clone) of leaf nor vegetative tissue and is not related to the development of a specified (per clone) leaf photosynthetic area. Finally, there is a strong indication that the death of the shoot is speeded by the presence of a high level of auxin.

Quantifying the growth of arbuscular mycorrhizal fungi: usefulness of the fractal dimension

Botany ◽  
2009 ◽  
Vol 87 (4) ◽  
pp. 387-400 ◽  
Author(s):  
Christine Juge ◽  
Annie Champagne ◽  
Andrew P. Coughlan ◽  
Nicolas Juge ◽  
Lael Parrott ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Mycorrhizal Fungi ◽  
Growth And Development ◽  
Time Course ◽  
Glomus Intraradices ◽  
Fungal Growth ◽  
Arbuscular Mycorrhizal ◽  
Hyphal Growth ◽  
Growth Cycle

The present study is, to the best of our knowledge, the first to investigate the use of the fractal dimension (FD) to quantify the growth and development of undisturbed, fully functional arbuscular mycorrhizal (AM) hyphae developing in vitro. The majority of the work focused on the model AM fungus Glomus intraradices DAOM 181602. The time course study and final measurements of an intact mature extraradical mycelium allowed us to compare the development of the mycelium and the FD value. The final FD value of 1.62 for the mature mycelium is similar to that obtained for highly branched root systems and tree crowns. The FD method was used to characterize the morphology of germinative and presymbiotic hyphae in the presence of stimulatory (strigolactone GR-24, 0.1 µmol·L–1 and bisphenol A, 10 µmol·L–1) and inhibitory (NaCl, 80 mmol·L–1) molecules, and the extraradical phase in the presence of an inhibitory molecule (NaCl, 80 mmol·L–1). Where possible, results were compared with those obtained using the traditional grid-line (GL) technique. The FD approach allowed treatment effects to be accurately quantified, both in germinative and extraradical phases. In the second case, this technique provided a single quantitative value of extraradical hyphal growth that included runner hyphae (RH) networks, and fine-branching (FB) ramifications. This is in contrast to the GL technique, which provides a value for the estimation of RH, but which is not suitable for accurately measuring FB hyphae. Given the ease with which the FD values can be calculated, and the fact that this method can provide a single value for the quantification of extraradical hyphal growth and development, we suggest that this method is useful for in vitro studies. Furthermore under certain situations of germinative or presymbiotic growth, it may be used in concert with the GL method to provide a greater degree of information about hyphal morphology. The usefulness and limits of the FD method at different stages of the AM fungal growth cycle are discussed.

Growth and development of the root apical meristem

2012 ◽  
Vol 15 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Serena Perilli ◽  
Riccardo Di Mambro ◽  
Sabrina Sabatini
Keyword(s):  
Growth And Development ◽  
Apical Meristem ◽  
Root Apical Meristem

MORPHOLOGICALLY DISTINCT STAGES IN THE GROWTH AND DEVELOPMENT OF RHIZOMES OF POA PRATENSIS L. AND THEIR CORRELATION WITH SPECIFIC GEOTROPIC RESPONSES

1965 ◽  
Vol 43 (10) ◽  
pp. 1163-1175 ◽  
Author(s):  
John E. Fisher
Keyword(s):  
Cross Section ◽  
Growth And Development ◽  
Apical Meristem ◽  
Poa Pratensis ◽  
Soil Surface ◽  
Leaf Primordium ◽  
Primary Stage ◽  
Secondary Stage ◽  
Small Pore ◽  
Tertiary Stage

Three distinct stages in the growth and development of the rhizomes of Poa pratensis L. can be distinguished. The names, primary, secondary, and tertiary are proposed to identify the stages. Primary stage rhizomes produce cataphylls elliptical in cross section, and poreless, or with a very small pore. Cataphyll primordia, initiated by the apical meristem, develop disproportionately, producing a hood-like cowling enclosing the apical meristem. The opening partially or completely closes by ontogenetic fusion. The geotropic response is plagiotropic Secondary stage rhizomes produce cataphylls with a marked longitudinal invagination. They are seldom poreless, and then only early in this stage. The apices are similar to primary stage apices. The geotropic response is diageotropic. Tertiary stage rhizomes progressively exhibit characteristics of true aerial shoots. Cataphylls develop a rudimentary leaf blade, ligule, and buliform-cell leaf-closure apparatus. However, a collar between blade and sheath does not form until the rhizome reaches the soil surface. The apex progressively develops the broad shield-shaped leaf primordium characteristic of aerial shoots. The geotropic response becomes strongly negatively orthogeotropic. Both the secondary and the tertiary stages are initiated by a change in the morphology of the apex and the cataphyll that precedes changes in the geotropic response of the rhizomes.

scholarly journals (280) Temporal and Spatial Expression of LEAFY and TERMINAL FLOWER 1 Homologues in Floral Bud of Japanese Pear and Quince

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1052B-1052 ◽  
Author(s):  
Tomoya Esumi ◽  
Ryutaro Tao ◽  
Keizo Yonemori
Keyword(s):  
Apical Meristem ◽  
Floral Meristem ◽  
Japanese Pear ◽  
Pyrus Pyrifolia ◽  
Rt Pcr ◽  
Inflorescence Development ◽  
Terminal Flower ◽  
Terminal Flower 1 ◽  
Floral Differentiation ◽  
Floral Bud

Japanese pear (Pyrus pyrifolia) and quince (Cydonia oblonga), both classified in the subfamily Maloideae, show differences in inflorescence architectures despite of the fact that they are genetically closely related. We previously isolated flowering related genes, LEAFY (LFY) and TERMINAL FLOWER 1 (TFL1) homologues, from these species and showed that they had two types of homologues for each gene. In this study, we examined the expression pattern of LFY and TFL1 homologues in these species by in situ hybridization and RT-PCR. The floral bud was dissected to small pieces under stereomicroscope; apical meristem, scales/bracts, pith, floral meristem, and inflorescence; and then used for RT-PCR. The LFY homologues were expressed in apical meristem and scales/bracts before the floral differentiation in both Japanese pear and quince. After floral differentiation, the expression was observed in floral meristem, scales/bracts and pith in both the species. The TFL1 homologues were strongly expressed in the apical meristem, but their expression was drastically decreased just before floral differentiation. It is considered that the decrease of expression of TFL1 homologues is a sign of floral initiation. The expression of TFL1 homologues was transiently increased at the beginning of floral differentiation in both species. Moreover, one of TFL1 homologues in Japanese pear was continuously expressed in the inflorescence part in the floral primordia, whereas expression of TFL1 homologues in quince almost completely disappeared after a solitary floral meristem was initiated. It was suggested that TFL1 homologues may also be involved in the inflorescence development of Japanese pear.

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