Anther

Anther (anther) is a dilated vesicular filament top part, is an important part of the stamen. yes Seed plant The tiny Spore As the grain heap, anther mature the gametophyte, can produce male gamete . Pollen produced by anther stamen, pistil composed of various methods to make. ovule Be fertilized .
Anther
Pollen sac Is the place that produces pollen.

Anther Basic situation

 Stamen Stamen
Stamens of flowers male The reproductive organs, is made out Pollen sac ( Microsporangium Anthers) (anther) was born in a thin filaments (filament) form.
Anther is dilated cystic filament top part is usually symmetrical, mostly spherical; Zosteraceae (Zostera Marina) for the linear, read cane (Alyxia) is a drum shaped, Pinaceae , Podocarpaceae Many have a balloon, Ephedra (Ephedra), Welwitschia (Welwitschia) pollen multi fold. Forget me not (Myosotis sylvatica) pollen minimum (4 ~ 8) * about (2 ~ 4 micron). Malvaceae Many kinds of Petunia, (Pharbi-tusnil), Musa (Musa) for 120 ~ 150 micron; Zosteraceae (Zostera Marina) pollen slender, about (1200 ~ 2900) * (3.5 ~ 9.5 micron).
The anther wall is composed of Epidermis Layer, fiber layer, middle layer and Tapetum A. The tapetum is a special cell layer surrounding the pollen sac,
With two or more nuclei, cells containing more DNA and protein, and fat and Carotenoid Other nutrients supply, with the development of pollen grains sustenance role. The mature pollen, pollen sac to shed pollen cracking.
According to anther in the filament of the student, can be divided into the medicine (all born in anther filaments, such as lotus), the bottom of a drug (with its base at anther filament top, such as flat fruit grass sedge, etc.), carrying medicine (with its back against the anther filaments such as, Verbenae , Dogwood Etc.), versatile anther (anther recumbent, its back to central point at top of filaments, such as Lily Several types of rice, etc.). Staminal filament separation, Compositae anther, synandria said.

Anther A way of life

 By way of growing By way of growing
The students in the anther filaments are:
1, the medicine: all from anther filaments, such as lotus .
2, the bottom of a drug: filament top is directly connected with the anther base, such as sedge, Berberis .
3, close all close to anther medicine: back in the filament, such as Tungoiltree .
4, versatile anther A: connected with anther filament top back, the stamen like t, easy to shake, such as Wheat Rice.
5, Divaricate medicine Complete separation chamber: a straight line, and was born in the filament top, such as rehmannia.
6, a word: a drug chamber base open, it was born in the top of filaments, more common in cruciferous plants, such as Pickpurse .
7, crown stamen: stamens with filaments and anthers in corolla, corolla, corolla and separation, such as: eggplant.

Anther Anther wall structure

The structure and function of the anther wall is as follows (from outside to inside):
1, Epidermis (skin)
The outer wall with Cuticle Containing, sporopollenin, and stomata and trichomes on the epidermis of some plants.
2, Endothecium (endothecium)
In anther tender period, with a large number of endothecium cells Starch grains . When the anthers close to mature cells, radial direction, Storage material gradually
 Flower wall structure Flower wall structure
Disappear, cell wall Except the other strip uneven thickened wall from tangential wall, thickened component is cellulose, slightly Lignin . Therefore, the endothecium also called fiber layer (fibrous layer). The same side of the junction of two pollen sacs Endothecium Cell, cell wall strip tension generated by the thickened, always keep to anther longitudinal rupture in parenchyma cells, pollen and elastic scattering. In some anther Poricidal dehiscence and Cleistogamy In plants, the endothecium is not thick strip.
3, Middle level (middle layer)
When the pollen sac sporogenous cells develop into Pollen mother cell Then, enter Meiosis When the storage material is absorbed in the middle, due to the proliferation and expansion of cells within the pollen sac volume produced by extrusion, the middle cells show flat. Stay at the mature stage, the middle has been absorbed, disintegration and disappearance. A few plants such as Lily Anther, middle cell wall A strip of thickened to some extent, it is mature, there are still some middle reserved.
4, Tapetum (tapetum)
The tapetum is anther wall of the inner layer, the unique secretory function, its effect on the development of pollen grains is essential. The tapetum cells were larger, Organelles Rich, early uninucleated, was not accompanied by the formation of new nuclear fission wall, it became two or more nuclei or polyploid Cells, these characteristics show that the tapetum has high physiological activity. In addition, containing more cells. RNA Protein and enzyme, and lipids, carotene and Sporopollenine Other substances. The development of the tapetum material for pollen provides an important role: callose enzyme secretion, timely decomposition Pollen mother cell and Four split The Callose The wall. microspore Separated from each other; the synthesis of proteins transported to the pollen wall, as Pollen wall Proteins play a role in mutual recognition and stigma receptivity; synthesis of sporopollenin formation of pollen wall material, has the characteristics of strong, strong resistance, if the tapetum is not normal, often appear male sterile The phenomenon of.

Anther anther development

Starting from the stamens in flower buds of stamen primordia, stamen primordia of the top for anther development area. The initial stage of anther development, has the advantages of simple structure, the outer layer
 The development of anther The development of anther
The original is a layer of epidermis, inside a group Ground meristem . Soon, the anther four of the corner breaks faster, the anther was four prism. Later in the four edge Protoderm The differentiation of columns of large volume, large nuclear, cytoplasmic dense, radial wall long, strong ability to split Sporogonium (archesp-orial cell). Then the archesporial cells of Periclinal Division Two, the inside and outside of a layer, the outer layer is the primary parietal layer (primary parietal layer); primary sporogenous cells (primary sporogenous cell), primary parietal layer cells to periclinal division and Anticlinal Division And gradually formed Endothecium , Middle level and Tapetum . Anther central cells gradually split, differentiation of vascular bundle and parenchyma cells, connective structure.
Pollen After mature fiber layer cell loss and mechanical stress caused by the gap in the anther is broken, shed pollen grains from the crack longitudinal crack formation. Pollen sac The wall because of the tapetum degenerated and disappeared, or only traces only Epidermis And the fiber layer.

Anther Cracking

Anther dehiscence is divided into the following four:
 Flower cracking Flower cracking
Fracture: two pollen sacs along the border of the longitudinal crack, such as rape, morning glory, Lily Etc..
The transverse crack along the central lateral anther dehiscence, such as Hibiscus , Hollyhock Etc..
Poricidal dehiscence Open a hole in the top of anther, pollen from small shed, such as tomatoes, tomato etc..
3-valved That split into several small flap in the anthers on the side wall of the valve hole by pollen shed, such as Camphor Etc..

Anther Special anther

1, anthers connate. Androecium Some or all of the anthers connate, such as chrysanthemum.
2, Orchid Anthers. The orchid plants pistils, stamens formation Gynostemium And the formation of special. Rostella Structure. The formation of anther clinandrium sag in rostella formed in front of a powder disk, or the formation of cysts. Synthesis of pollen clumps, connected with the rostellum, may be carrying insects.

Anther In vitro culture

The way to take anther cultured in vitro. Anther culture in vitro Belong to sexual reproduction .
Anther culture is often mistaken Asexual reproduction A type of main reason is: the anther culture development is the starting point Mononuclear pollen No, the germ cells (sperm) production. The tissue culture of vegetative Cloning technology . With the no sexual reproduction of cells.
The essence of asexual reproduction is Offspring With the parent containing the same genetic material That is, Genotype Invariant (without regard to the offspring Gene mutation ). The development of anther culture of mononuclear pollen (starting point Chromosome number N) is the parent (chromosome 2N) Meiosis Formed by genetic material and maternal differences develop into haploid plants greatly.
2 tissue culture The explants used (2N chromosomes) by Mitosis The formation, explant and used here (dye
 Flower formation Flower formation
Body color number N) is formed by meiosis, explant is not the usual sense of.
3 sexual reproduction The essence is to produce gender gamete (by Meiosis The formation, chromosome number N), and has sexual gametes. Which also have the sexual reproduction in the usual sense, but only through meiosis to produce gametes, had already completed a key step of sexual reproduction, and the nature of many haploid The form is very similar, such as the male males. Parthenogenesis Just the same, germ cell The formation of combined gender gametes.
Anther breeding is generally pollen culture in vitro in mononuclear period (anther microspore). Through training to make it leave the normal developmental pathway (i.e. the formation of mature pollen finally produced sperm The way and differentiate into haploid plants), which is the main method to obtain haploid plants. After preparation to substantially culture medium Anthers inoculated and cultured for three steps.
Grown by Pollen Haploid there are generally two ways:
The formation of pollen Division Callus (group that parenchyma cells differentiation program is very low), then the callus differentiation of roots and buds, and finally the formation of plants.
The formation of pollen Division Embryoid (not from a zygote embryo called embryoid bodies), and then by embryoid plantlets. When anther grow seedlings reached a certain size, should adjust the temperature, temperature and light conditions, the seedlings get exercise and gradually adapt to natural environmental conditions, and then removed from the plant in the soil from the tube, for cultivation and management in general.