Megasporogenesis and microsporogenesis. Megasporogenesis, Microsporogenesis, and Development of Female and Male Gametophytes of Ziziphus jujuba Mill. ‘Zhongqiusucui’ in: HortScience Volume 54 Issue 10 (2019) 2022-10-15

Megasporogenesis and microsporogenesis Rating: 7,4/10 1934 reviews

Megasporogenesis and microsporogenesis are two fundamental processes that occur in the reproductive structures of flowering plants, also known as angiosperms. These processes involve the formation and development of female and male gametophytes, respectively, which are essential for sexual reproduction in angiosperms.

Megasporogenesis is the process by which a megasporocyte, or a large cell that gives rise to a megaspore, is formed. This process begins with the meiosis of a diploid megasporocyte, which results in the production of four megaspores. However, only one of these megaspores will survive and develop into a female gametophyte, also known as the embryo sac. The other three megaspores will degenerate.

The female gametophyte is responsible for producing the egg cell, which will eventually be fertilized by a male gametophyte. The fertilized egg cell will then give rise to a new plant individual.

Microsporogenesis, on the other hand, is the process by which microspores, or small cells that give rise to male gametophytes, are formed. This process also begins with meiosis, which results in the production of four microspores. These microspores will then develop into male gametophytes, also known as pollen grains.

The pollen grain contains the male gametophyte, which consists of two cells: the generative cell and the tube cell. The generative cell will eventually divide into two sperm cells, which will be used to fertilize the egg cell during pollination. Pollination is the process by which pollen is transferred from the anther, the male reproductive structure of the flower, to the stigma, the female reproductive structure.

Both megasporogenesis and microsporogenesis are essential for sexual reproduction in angiosperms. Without these processes, the production of female and male gametophytes would not be possible, and fertilization and the formation of new plant individuals would not occur.

In summary, megasporogenesis is the process by which female gametophytes are formed, while microsporogenesis is the process by which male gametophytes are formed. Both of these processes are essential for sexual reproduction in angiosperms and involve the meiotic division of diploid cells. The female gametophyte produces the egg cell, which will be fertilized by the male gametophyte, while the male gametophyte produces sperm cells that will fertilize the egg cell. Together, these processes ensure the continuation of the plant species through sexual reproduction.

Megasporogenesis, Microsporogenesis, and Development of Female and Male Gametophytes of Ziziphus jujuba Mill. ‘Zhongqiusucui’ in: HortScience Volume 54 Issue 10 (2019)

megasporogenesis and microsporogenesis

A Two anther in one bud. D The grade 0 bud on the inflorescence on day 4 arrow. I Abnormal embryo sac with a small number of inclusions arrow. Microspore mother cells undergo meiosis and result in microspores which are n cells. For example — Family Polygonaceae, Piperaceae and ovules of most gymnosperms. H Abnormal anther filled with unknown plastids. The archesporial cell divided and formed the primary sporogenous cell, which then generated secondary sporogenous cells through multiple rounds of mitosis.

Next

Megasporogenesis

megasporogenesis and microsporogenesis

Ovule or megasporangium develops from the inner wall of the ovary. I Meiosis I metaphase blue arrow , early anaphase black arrow , and late anaphase red arrow. D Abnormal embryo sac with only polar nucleus and one antipodal cell arrows. N The oocyte near the micropyle arrow , the central cell containing two polar nuclei arrow , and antipodal cells arrow , and one antipodal cell near the chalaza arrow. Only one out of the four megaspores formed is functional. C Abnormal embryo sac with only polar nucleus and egg cells arrows. This finding indicates that some cell degeneration derived from megasporocyte meiosis is genetically determined.

Next

Megasporogenesis in Plants: Important Details

megasporogenesis and microsporogenesis

The secondary sporogenous cell continued to develop into microspore mother cells that had characteristics of a large cell volume, large nucleus, and dense cytoplasm The microsporocytes in each locule were at the same stage during meiosis and exhibited synchrony. When the anther matures, it releases all of the pollen grains for fertilisation. Megasporangia are known as ovules. Morphological development characteristics of flower buds at the inflorescence developing stage. T Binucleate stage blue arrow.

Next

Microsporogenesis and megasporogenesis in Sinofranchetia (Lardizabalaceae)

megasporogenesis and microsporogenesis

Microsporangia is a collection of many containers of sporogenous tissue while a single container is called a microsporangium. As a result, the endothecium shortens and ruptures the anther lobe wall in the vicinity of the stomium. The four nuclei are arranged tetrahedrally and soon get enclosed with cell walls. B Longitudinal section of two ovules in one chamber of ovary. Rarely does an anther have a single microsporangia unisporangiate on just one lobe for example, Arceuthobium. Among the different anthers in the same floral bud, as well as the four locules in the same anther, the microsporocytes had asynchronous meiosis. The discrepancy may be attributable to the genetic characteristics in different jujube cultivars, although the specific causes still need to be further investigated.

Next

Microsporogenesis

megasporogenesis and microsporogenesis

B The grade 0 bud on the inflorescence on day 2 arrow. Microsporogenesis is an important process in plant reproduction, which includes several series of developmental stages from sporogenous cells to microspores. The microspores or the pollen grains undergo mitotic division to form vegetative and generative cells. Ans: The end product of microsporogenesis is a pollen grain that further develops into the male gametes. The multilayered body of the ovule is called nucellus which is enclosed by one or two protective layers called integuments, except for a small pore at one end called the micropyle. C Abnormal embryo sac with only polar nucleus and egg cells arrows.

Next

Megasporogenesis,Microsporogenesis and Development of Female and Male Gametophytes of Paeonia delavayi opportunities.alumdev.columbia.edu

megasporogenesis and microsporogenesis

H Meiosis I prophase. B Anther 1 of the bud in C Anther 2 of the bud in D In the same anther, a pollen sac in meiosis I late anaphase blue arrow , and another at the meiosis II telophase red arrow. B Longitudinal section of two ovules in one chamber of ovary. M Meiosis II metaphase blue arrow. The generative cell further divides to form the male gametes. N Two degenerated ovules in one ovary arrows. A The grade 0 bud on the inflorescence in day 1 arrow.

Next

What is difference between microsporangium and Microsporogenesis?

megasporogenesis and microsporogenesis

K The grade 0 bud on the inflorescence on day 11 arrow. From day 1 at the inflorescence developing stage, the marked grade 0 buds on the inflorescence were observed and photographed Fig. Microsporangia is the structure that is mainly responsible for the production and releases of pollen grains. What is the Difference Between Microsporogenesis and Megasporogenesis? L The grade 0 bud on the inflorescence on day 12 arrow. Any unpredictable disturbance during the meiotic process reduces gamete viability. Complete Answer: Division of the tapetal cell takes place by mitosis and after mitosis cytokinesis does not take place and this type of mitosis is known as endomitosis and it results in the binucleate or multinucleate tapetum. Thanks are due to Juan Chen and Rongyan Hong for assistance with the experiments, and to Professor Sen Wang for valuable discussion.

Next

[PDF] Megasporogenesis, Microsporogenesis, and Development of Female and Male Gametophytes of Ziziphus jujuba Mill. ‘Zhongqiusucui’

megasporogenesis and microsporogenesis

I Abnormal embryo sac with a small number of inclusions arrow. E The grade 0 bud on the inflorescence on day 5 arrow. The functional megaspore grows, and its nucleus undergoes mitotic divisions to produce eight haploid nuclei. The newly revealed embryological characters are the basic type of anther wall formation, isolateral microspore tetrads, and both the epidermis and the parietal cell being involved in the formation of the crassinucellate ovules. Abstract To investigate whether reproductive disorders exist in the sexual reproduction of Ziziphus jujuba Mill.

Next

Difference Between Microsporogenesis and Megasporogenesis

megasporogenesis and microsporogenesis

Microspores in the other one were abnormal development and surrounded by unknown plastid closely red arrow. P Tetrad phase blue arrow. The embryological peculiarities in Lardizabalaceae are discussed. F Early stage tapetum and secondary sporogenous cell. It provides nourishment to the developing pollen grains.

Next