scholarly journals The MSP1 Gene Is Necessary to Restrict the Number of Cells Entering into Male and Female Sporogenesis and to Initiate Anther Wall Formation in Rice

2003 ◽  
Vol 15 (8) ◽  
pp. 1728-1739 ◽  
Author(s):  
Ken-Ichi Nonomura ◽  
Kazumaru Miyoshi ◽  
Mitsugu Eiguchi ◽  
Tadzunu Suzuki ◽  
Akio Miyao ◽  
...  
Keyword(s):  
Anther Wall ◽  
Male And Female ◽  
Wall Formation ◽  
Msp1 Gene ◽  
Number Of Cells

scholarly journals Reproductive potential and nesting effects of Osmia rufa (syn. bicornis) female (Hymenoptera: Megachilidae)

2016 ◽  
Vol 60 (1) ◽  
pp. 75-86 ◽  
Author(s):  
Karol Giejdasz ◽  
Monika Fliszkiewicz ◽  
Andrea Bednárová ◽  
Natraj Krishnan
Keyword(s):  
Sex Ratio ◽  
Reproductive Potential ◽  
Female Offspring ◽  
Male Offspring ◽  
Nesting Behavior ◽  
Solitary Bee ◽  
Male And Female ◽  
Individual Female ◽  
The Family ◽  
Number Of Cells

Abstract The red mason bee Osmia rufa is a solitary bee belonging to the family Megachilidae, and is prone to nest in aggregations. Each female builds a nest separately in pre-existing cavities such as holes in wood and walls or empty plant stems. This is done by successively setting the cells in a linear series. In this study, we elucidate the nesting behavior and the reproductive potential of a single O. rufa female. The reproductive potential of nesting females was evaluated after the offspring finished development. We observed that an individual female may colonize up to five nest tubes and build 5-34 cells in them (16 on an average). During the nesting time the number of cells decreased with the sequence of nest tubes colonized by one female, which built a maximum of 11 cells in the first occupied nest and 5 cells in the last (fifth nest). Our observations indicated that 40% of nesting females colonized one nest tube as compared to 7% colonizing five nest tubes. Furthermore, in subsequent nest tubes the number of cells with freshly emerged females gradually decreased which was the reverse with males. Thus, the sex ratio (proportion of male and female offspring) may change during the nesting period. The female offspring predominated in the first two nesting tubes, while in the subsequent three tubes male offspring dominated. We also cataloged different causes of reduction in abundance of offspring in O. rufa females such as parasitization or problem associated with moulting.

scholarly journals Anther Wall Formation in Solanaceae Species

2002 ◽  
Vol 90 (6) ◽  
pp. 701-706 ◽  
Author(s):  
C. CARRIZO GARCIA
Keyword(s):  
Anther Wall ◽  
Wall Formation ◽  
Solanaceae Species

Floral development of Maidenia rubra Rendle, (Hydrocharitaceae)

1983 ◽  
Vol 31 (6) ◽  
pp. 585 ◽  
Author(s):  
CA McConchie
Keyword(s):  
Floral Development ◽  
Floral Morphology ◽  
Male Flower ◽  
Pollen Grains ◽  
Anther Wall ◽  
Male And Female ◽  
The Third ◽  
Male Inflorescence ◽  
Single Flower

Floral development of Maidenia rubra was followed from initiation to maturity. Plants are dioecious. Both male and female inflorescences develop from complexes initiated subapically. Complexes have three meristematic components that include two inflorescence initials flanking a central primordium; these form sequentially in the axil of the preceding initial. The third component also produces an inflorescence and branches sympodially to form further floral initials that have a spiral arrangement. The female inflorescences produce a single flower only with an inferior, unilocular ovary and three sepals, staminodes and bifid stigma. In the locule, numerous bitegmic ovules, borne panetally, are produced. A male inflorescence produces hundreds of small flowers that are released and float to the surface individually. Each male flower has three sepals, a staminode and two stamens, each anther consisting of three locules with eight pollen grains. Prior to maturation, the anther wall breaks down leaving a membraneous layer that assists in binding the octad of pollen grains together. Both male and female inflorescences are enclosed in a pair of fused bracts. The floral morphology is compared with other closely related genera in the Hydrocharitaceae and the unique features are assessed.

Anther wall development and structure in wild tomatoes (Solanum sect. Lycopersicon): functional inferences

2006 ◽  
Vol 54 (1) ◽  
pp. 83 ◽  
Author(s):  
Carolina Carrizo García ◽  
Gloria E. Barboza
Keyword(s):  
Anther Wall ◽  
Mechanical Support ◽  
Anther Dehiscence ◽  
Buzz Pollination ◽  
Dorsal Wall ◽  
Pollination Mechanism ◽  
Number Of Layers ◽  
Solanum Sect ◽  
Anther Wall Development ◽  
Number Of Cells

Development of the anther wall and its structure at maturity in wild tomatoes (Solanum sect. Lycopersicon) are described, and the features are discussed in relation to anther dehiscence and the buzz-pollination mechanism. The anther wall formation follows two different patterns in the same microsporangia and a high number of cells divisions may occur. The number of layers formed varies across the ventral, dorsal and lateral surfaces of each theca. Large epidermal cells develop, lining the stomium, and they could possibly be involved in stomium opening. Cells with thickenings are formed in the apical fifth of the anther, where the tissues seem to degenerate after the stomium opening, forming a wider aperture through which the pollen can be shed. The multilayered dorsal wall remains swollen and could act as an attractant to pollinators and as mechanical support. The apparently disordered anther wall development sets up different structures across and along the anther, which can be interpreted as histological adaptations to the buzz-pollination mechanism.

Combination of sequences of cell divisions in the anther wall formation in Solanaceae species

Flora ◽  
2003 ◽  
Vol 198 (3) ◽  
pp. 243-246 ◽  
Author(s):  
Carolina Carrizo García
Keyword(s):  
Anther Wall ◽  
Wall Formation ◽  
Cell Divisions ◽  
Solanaceae Species

scholarly journals Embryology and fertility of the natural tetraploid Lessingianthus plantaginoides (Asteraceae, Vernonieae): taxonomic implications

Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Yanina de Jesús Pérez ◽  
Maria Betiana Angulo ◽  
Ana Honfi ◽  
Massimiliano Dematteis
Keyword(s):  
Embryo Sac ◽  
Pollen Grains ◽  
Anther Wall ◽  
Meiotic Analysis ◽  
Polygonum Type ◽  
Male And Female ◽  
Ontogenetic Study ◽  
Colonization Potential ◽  
Taxonomic Implications ◽  
Anther Wall Development

Abstract Lessingianthus plantaginoides (Vernonieae, Asteraceae) is a small natural tetraploid shrub that inhabits rocky highlands from South America. The population studied inhabits and covers an extensive region of a private reserve with high local biodiversity and animal and plant endemisms. With the purpose of providing insights into the cyto-embryology of this tetraploid species, the aims of this study were: to perform an ontogenetic study of the male and female gametophytes of L. plantaginoides; to carry out detailed meiotic analysis and evaluate the fertility of this species; to document and provide highlights on taxonomic implications of their reproductive aspects. Lessingianthus plantaginoides presented the following male and female gametophyte traits: dicotyledonous type of anther wall development, tetrahedral tetrads, 3-celled mature pollen grains; development of the chalazal megaspore, monosporic embryo sac and Polygonum type of megagametophyte development. The meiotic behavior was regular, the spores were tetrads of equal size and the pollen grains were highly stainable. Lessingianthus plantaginoides is a highly diplodized autotetraploid that reproduces sexually and has high meiotic regularity; which is apparently responsible for its colonization potential. It now seems certain that polyploid speciation plays a significant role in the establishment and diversification of the genus.

scholarly journals Megasporogenesis, Microsporogenesis, and Development of Female and Male Gametophytes of Ziziphus jujuba Mill. ‘Zhongqiusucui’

HortScience ◽  
2019 ◽  
Vol 54 (10) ◽  
pp. 1686-1693
Author(s):  
Fengxia Shao ◽  
Sen Wang ◽  
Juan Chen ◽  
Rongyan Hong
Keyword(s):  
Outer Integument ◽  
Embryo Sac ◽  
Morphological Characteristics ◽  
Development Stage ◽  
Anther Wall ◽  
Inflorescence Development ◽  
Male And Female ◽  
Floral Buds ◽  
Ziziphus Jujuba ◽  
Floral Bud

To investigate whether reproductive disorders exist in the sexual reproduction of Ziziphus jujuba Mill. ‘Zhongqiusucui’ and to understand the reproductive biology of ‘Zhongqiusucui’ and genetic improvements in jujube trees, we used ‘Zhongqiusucui’ flowers at different developmental stages as materials and conducted field and microscopic observations on the developmental pattern of mega- and microsporogenesis, as well as on the development of male and female gametophytes. The results show the following. 1) From the inflorescence development stage to flowering, the grade 0 bud on the inflorescence exhibited an increase in horizontal diameter, longitudinal diameter, peduncle length, and bud weight, but the rates of increase were different. From day 1 to day 5 after the inflorescence had developed, floral buds mostly grew horizontally. Day 5 was the floral bud flattening stage. From day 6 to day 8 after the inflorescence had developed, floral buds mostly grew longitudinally, and day 8 was the floral bud enlarging stage. 2) The stamens of ‘Zhongqiusucui’ had five anthers, and there were four locules per anther. The anther wall consisted of epidermis, endothecium, one- to two-layered middle layer, and a secretory-type tapetum. In addition, the development of the anther wall belonged to the basic type. The cytokinesis of the microsporocytes was synchronous, the tetrads mostly arranged as a tetrahedron, and the mature pollen had three germ pores, three grooves, and was bicellular pollen. During meiosis, the microsporocytes in each locule were at the same phase and therefore exhibited synchrony. Among the different anthers in the same floral bud, as well as the four locules in the same anther, the microsporocytes had asynchronous meiosis. 3) The pistils in the ‘Zhongqiusucui’ had two ovaries, two anatropous ovules, inner and outer integument, crassinucellate tetrads formed by the meiosis of megasporocytes aligned linearly along the nucellus, megaspore at the chalazal end that developed into the functional megaspore, which underwent mitotic division three times and developed into the mature embryo sac containing seven cells and eight nuclei, and embryo sac development of the Polygonum type. 4) The external morphology of the ‘Zhongqiusucui’ floral buds correlated with the internal developmental stage of the male and female gametophyte. Therefore, the internal developmental progress of the stamen and pistil can be determined by the external morphological characteristics of the floral buds.

GENETIC VARIATION IN ADRENAL STRUCTURE: STRAIN DIFFERENCES IN QUANTITATIVE CHARACTERS

1968 ◽  
Vol 40 (2) ◽  
pp. 215-229 ◽  
Author(s):  
J. G. M. SHIRE ◽  
S. G. SPICKETT
Keyword(s):  
Adrenal Glands ◽  
Strain Differences ◽  
Inbred Strains ◽  
Relative Volume ◽  
Zona Fasciculata ◽  
Male And Female ◽  
Adult Mice ◽  
Quantitative Characters ◽  
Males And Females ◽  
Number Of Cells

SUMMARY Five quantitative parameters of adrenal structure have been measured for the adrenal glands of young adult mice of three inbred strains. Male and female A/Cam, CBA/FaCam and SF/Cam mice were compared in a first experiment and A and CBA males in a second. The findings in the two experiments were similar. Significant strain differences, sex differences, and strain differences in sex difference, were found for the volume of the permanent cortex, and for the number of cells in it. There were strain differences in the volume of the cells of the zona fasciculata, and striking strain differences in the absolute and relative volume of the X-zone in female mice. Significant strain differences were also found in the volume of the medulla in males and females. The findings are discussed in relation to the observed differences between the strains in adrenal weight, and in relation to the regulation of the size of the several zones of the cortex.

scholarly journals Genesis of the generative structures Platycodon grandiflorus (family Сampanulaceae)

2021 ◽  
pp. 87-97
Author(s):  
S. V. Shevchenko
Keyword(s):  
Embryo Sac ◽  
Pollen Grains ◽  
Southern Coast ◽  
Polygonum Type ◽  
Male And Female ◽  
Research Results ◽  
Wall Formation ◽  
Sporogenous Tissue ◽  
High Viability ◽  
The Crimea

The article presents the research results of the genesis of the elements of the microsporangium wall, sporogenous tissue, microspores, megaspores, male and female gametophytes of the Platycodon grandiflorus . The types of formation of the structures mail generative sphere (dicotyledonous type of microsporangium wall formation, simultaneous type of the tetrad microspores development, 3-cells of the pollen grains with 6-th pores, Polygonum - type of the formation embryo sac) have been established. A high viability of pollen grains was established during pollination and possibility of obtaining complete seeds when growing this species in the conditions of the Southern Coast of the Crimea.

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