Initiation of floral organs in Nicotiana tabacum

1973 ◽  
Vol 51 (9) ◽  
pp. 1611-1617 ◽  
Author(s):  
G. S. Hicks
Keyword(s):  
Nicotiana Tabacum ◽  
Periclinal Division ◽  
Floral Organs ◽  
Floral Buds ◽  
Tunica Layer ◽  
Routine Procedures

Floral buds of Nicotiana tabacum were fixed, sectioned, and stained by routine procedures, then analyzed microscopically. Initiation and emergence of all four classes of floral organs involved periclinal division in the second tunica layer (T2) and division of corpus cells. The extent of periclinal T2 divisions was different in different organs. Plasmolysis of tunica and corpus cells was observed at organ sites. The results generally parallel those of other studies.

scholarly journals Flower Bud Differentiation and Development of ‘Jinsi No.4’ Jujube (Ziziphus jujuba Mill.) in Hunan Province of Southern China

2017 ◽  
Vol 11 (1) ◽  
pp. 9-15
Author(s):  
Feng Zou ◽  
Jinghua Duan ◽  
Huan Xiong ◽  
Deyi Yuan ◽  
Lin Zhang ◽  
...  
Keyword(s):  
Southern China ◽  
Paraffin Section ◽  
Hunan Province ◽  
Flower Bud ◽  
Floral Organs ◽  
Floral Buds ◽  
Final Yield ◽  
Ziziphus Jujuba ◽  
Single Flower ◽  
Floral Bud

Ziziphus jujuba Mill. is one of the most important fruit crops and has been cultivated in China for more than 4000 years. Z. jujuba fruit is rich in nutritional and medicinal values. Compared to other wood fruits, Z. jujuba is unique in its flowering and fruiting characteristics. Floral buds differentiation and formation of Z. jujuba is an essential process that affects yield. Z. jujuba ‘Jinsi No.4’ blooms profusely, yet its final yield is low. In this study, the floral bud differentiation and development of ‘Jinsi No.4’ were examined by paraffin section. Results showed that the floral buds of ‘Jinsi No.4’ differentiated in the current year and started from early April. The duration of a single flower differentiation was short, taking only 7 days for maturation of flowers buds. Floral bud differentiation of ‘Jinsi No.4’ can be divided into six stages, i.e., pre-differentiation, initial differentiation, sepal differentiation, petal differentiation, stamen differentiation, and pistil differentiation. Flower development experienced seven stages, i.e., alabastrum, alabastrum break, sepal flattening, petal flattening, stamen flattening, filament withering, and ovule swelling. Dysplasia was observed in some floral organs in Z. jujuba ‘Jinsi No.4’, suggesting that the dysplasia of floral organs may be one of the main reasons for low yields. Our findings on flower bud development in ‘Jinsi No.4’ will contribute to its production and flowering management in Hunan area of southern China.

Floral histogenesis in the Monocotyledons. IV. The Liliaceae

1960 ◽  
Vol 8 (3) ◽  
pp. 213 ◽  
Author(s):  
C Barnard
Keyword(s):  
Early Ontogeny ◽  
Periclinal Division ◽  
Flower Primordia ◽  
Independent Origin ◽  
Tunica Layer ◽  
Floral Histogenesis ◽  
In Cells

An account is presented of floral histogenesis in Bulbine bulbosa R.Br. and Stypandra glauca R.Br. The apex of the floral axis in both species has a two-layered tunica, and bracts arise through the periclinal division of cells of the inner layer of the tunica (hypodermis). In Bulbine, axillary flower primordia are initiated in the periclinal division of subhypodermal cells; in Stypandra the flower primordia are terminal and arise directly from the apices of branches of the inflorescence. In both species the perianth'members originate, in the same manner as the bracts, through periclinal divisions in cells of the hypodermis. Periclinal divisions may occur in the cells of the outer tunica layer (dermatogen) after the prinlordia are well formed. Divisions in subhypodermal cells in the area of perianth initiation are associated with the formation of a provascular strand and it is doubtful if such divisions contribute anything to the tissue of the perianth primordium itself. The stamens are initiated in the periclinal division of both hypodermal and subhypodermal cells. In Bulbine the carpels develop through periclinal divisions in the hypodermis and dermatogen. The placentas appear to arise through divisions in subhypodermal cells as structures adnate to the carpels. In Stypandra the carpels arise in a quite different manner through the periclinal division of subhypodermal cells. The margins of the carpels develop as the placentas and there is no suggestion in the early ontogeny of the gynaecium that the placentas have an independent origin.

Différenciation in vitro et de novo d'organes floraux directement a partir des couches minces de cellules de type epidermique de Nicotiana tabacum. Etude au niveau cellulaire

1974 ◽  
Vol 52 (11) ◽  
pp. 2319-2322 ◽  
Author(s):  
Nguyen Thi Dien ◽  
M. Tran Thanh Van
Keyword(s):  
Nicotiana Tabacum ◽  
Mitotic Activity ◽  
Cell Walls ◽  
De Novo ◽  
Tritiated Thymidine ◽  
Flower Buds ◽  
Floral Organs ◽  
Epidermal Tissue

Floral organs (sepals, petals, stamens, carpels) have formed de novo and directly from explants composed of 3 to 6 layers of epidermal and subepidermal cells; these organs originated from the subepidermal layer. The first symptoms of the resumption of mitotic activity included incorporation of tritiated thymidine at the level of the subepidermal layer followed by new cell walls observed after 24 h of culturing. On the average, organogenesis from cells derived from the subepidermal layer was completed after about 10 days.This work demonstrates that the epidermal tissue can form flower buds de novo and directly. [Translated by the journal]

Knockdown of NtMed8, a Med8-like gene, causes abnormal development of vegetative and floral organs in tobacco (Nicotiana tabacum L.)

2011 ◽  
Vol 30 (11) ◽  
pp. 2117-2129 ◽  
Author(s):  
Fengqing Wang ◽  
He Wei ◽  
Zhijun Tong ◽  
Xiaobo Zhang ◽  
Zemao Yang ◽  
...  
Keyword(s):  
Nicotiana Tabacum ◽  
Abnormal Development ◽  
Floral Organs ◽  
Nicotiana Tabacum L

Role of gibberellins in the development of floral organs of the gibberellin-deficient mutant, ga1-1, of Arabidopsis thaliana

1999 ◽  
Vol 77 (7) ◽  
pp. 944-954 ◽  
Author(s):  
Nobuharu Goto ◽  
Richard P Pharis
Keyword(s):  
Arabidopsis Thaliana ◽  
Pollen Development ◽  
Seed Set ◽  
Reproductive Function ◽  
Optimal Dose ◽  
Floral Organ ◽  
Deficient Mutant ◽  
Flower Stalk ◽  
Floral Organs ◽  
Floral Buds

The gibberellin-deficient mutant, ga1-1 (NG5) of Arabidopsis thaliana, when induced by 16-h-long days, will form floral buds. However, the flower stalk is very short and floral organs within the flowers remain undeveloped; petal growth is arrested, with the petals being scaly and translucent, the stamens are abortive, the filaments do not elongate, and the pollen does not mature. Sepals and pistils are also underdeveloped. All of the above defects of this mutant can be completely eliminated if certain gibberellins (GAs) are applied to the young floral buds. That is, the applied GA acts to normalize not only plant height but also development of floral organs, thereby yielding good seed set from self-pollination. There were appreciable differences in the efficacy of different GA structures in normalizing the various floral organs. For seed production, the order of efficacy was 2,2-dimethyl GA4 > GA7 > GA3 = GA4 > GA1 > GA5 = GA9. When 2,2-dimethyl GA4 was used to determine an optimal GA dose, the following pattern emerged: filament elongation and pollen development, 1-10 ng; petal and pistil growth, 1 ng; sepal growth, 0.1 ng; papilla elongation, 0.01 ng. However, one application at these doses was insufficient to normalize the flowers, which were formed one after another, and a continuing supply of GA at the optimal dose was required for normal flower development and seed set. We conclude from this work that GAs play an essential role in the development of floral organs of Arabidopsis and that petals and stamens (filaments and pollen) in particular develop normally only when GAs are present at the optimal level.Key words: Arabidopsis thaliana, floral organ development, gibberellin, gibberellin-deficient mutant, petal and pollen development, reproductive function.

Distribution of newly formed hepatic glycogen in adrenalectomized rats as observed by radioautography after injection of 3H-galactose

1984 ◽  
Vol 42 ◽  
pp. 228-229
Author(s):  
J. E. Michaels ◽  
J. T. Hung ◽  
E. L. Cardell ◽  
R. R. Cardell
Keyword(s):  
Glycogen Synthesis ◽  
Hepatic Glycogen ◽  
Electron Microscopic ◽  
Routine Procedures ◽  
Silver Grains ◽  
Synthetic Glucocorticoid ◽  
Adrenalectomized Rats

In order to study early events of glycogen synthesis, we have used adrenalectomized (ADX) rats fasted overnight and injected with the synthetic glucocorticoid dexamethasone (DEX) to stimulate glycogen synthesis. Rats were given DEX 0-5 hr prior to sacrifice and injected with 2 mCi 3H-galactose 1 hr prior to sacrifice. Liver was prepared for light (LM) and electron microscopic (EM) radioautography by routine procedures.The concentration of silver grains over hepatic cytoplasm was measured in LM radioautographs using a Zeiss Videoplan. The hepatocytes were categorized as unlabeled if no silver grains (gr) were present, lightly labeled (<10gr/100 μm2 cytoplasm) or intensely labeled (>10 gr/1002 μm cytoplasm). Although very few hepatocytes showed heavy labeling after 1 hr treatment with DEX, by 2 hr after DEX treatment 8% of the cells distributed throughout the lobule were intensely labeled.

Banded Structures in the Connective Tissue of Meningioma

1976 ◽  
Vol 34 ◽  
pp. 234-235
Author(s):  
C. N. Sun ◽  
H. J. White
Keyword(s):  
Connective Tissue ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Collagen Fibrils ◽  
Lead Citrate ◽  
Connective Tissues ◽  
Native Collagen ◽  
Routine Procedures

Previously, we have reported on extracellular cross-striated banded structures in human connective tissues of a variety of organs (1). Since then, more material has been examined and other techniques applied. Recently, we studied a fibrocytic meningioma of the falx. After the specimen was fixed in 4% buffered glutaraldehyde and post-fixed in 1% buffered osmium tetroxide, other routine procedures were followed for embedding in Epon 812. Sections were stained with uranyl acetate and lead citrate. There were numerous cross striated banded structures in aggregated bundle forms found in the connecfive tissue of the tumor. The banded material has a periodicity of about 450 Å and where it assumes a filamentous arrangement, appears to be about 800 Å in diameter. In comparison with the vicinal native collagen fibrils, the banded material Is sometimes about twice the diameter of native collagen.

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