The development of lily medicine and pollen grains

the development of lily medicine and pollen grains male is one of the important components of flowers. The pollen mother cells are produced in the flower medicine of the male. Small spores are formed by subtring the mother cells of pollen. The number of chromosomes of small spores is half the number of chromosomes of pollen parent cells, and is a ptocyte. This is an asexual reproductive process. Then, by the small spores further development, the formation of mature pollen particles, that is, male lipenes.experiment took lily as a material and took the permanent production of lily medicine in different developmental periods to observe and understand the development process of pollen grains and the basic structure of flower medicine. Lily pollen grains are two-celled, and mature pollen grains contain only one nutrient cell and one reproductive cell.(i) the structure of lilyfirst look at the model or physical specimen of a lily, the whole picture of lily and basic structural characteristics have a understanding. Lily is a single leaf plant and is a typical triumte flower. Flowers are two rounds, three rounds; six males, born in two rounds; females are born from three hearts, three rooms in the sub-room, the central axis tire seat, each sub-room in the birth of two columns of embryo beads. When observing physical objects or models, the morphological structure characteristics of lily males and females are mainly understood.。(2) Lily drug production in different developmental periods observation Lily in different developmental periods of the permanent production of flower medicine may generally include spore-forming
tissue
period, pollen mother cell deseed division pre-I before and after, two and four parts, single-core pollen particles and mature pollen particles and other periods. The method of making is to strip lily buds of different sizes before and after the minus split and flowering potions before and after flowering to fix (when the flowering pills are too young, the males can be fixed together with the females).
then made into a potion cross-cut face permanently. On a production, may include a number of flower drug cross-cutting surfaces in the same development period, or may include a number of flower drug cross-cutting surfaces with different developmental periods. Therefore, when observing the permanent production, the whole picture of the production should be understood under the low-fold object lens first, to distinguish its development period and the various structural parts of the flower medicine. Then, in the same development period of the flower medicine cut in the selection of a better cut face position, the conversion of high-fold object lens for further observation.1. The permanent production of lily medicine during spore tissue creation period was observed under a low-multiplied object lens. Note that due to this period of small flower medicine, generally do not peel the production alone, but take the female, male as a whole for burial, production. Therefore, the permanent production for young flower medicine and children's room together cross-cutting. Lily is a three-figure flower, with six born males and a three-room room made of three hearts.
in a permanent production, the structure of the six butterfly-shaped surroundings is a flower-shaped cross-section, and in the middle a triangle is a sub-room cross-cut (in some permanent productions, sometimes there are only five flower-shaped sides around).
looking at the cross-section of lily medicine, we can see that each flower medicine consists of four chambers, each room is a pollen sac (or medicine room). There is a drug gap between pollen sacs. In the middle of the drug barrier, one-dimensional tube bundles can be seen passing through, and the rest of the drug compartment is thin-walled tissue. Sometimes, in the permanent production can also be seen in the space under the drug barrier, there is a flower wire cross-cut, the flower wire also has a one-dimensional tube bundle through. Pay attention to distinguish between silk and medicine.look closely at one of the pollen sacs with a complete cut and clear layers under a high-fold object mirror. During the spore-forming tissue period, the differentiation of the various layers of the flower wall is not obvious, the whole flower drug is the outerst layer of skin cells, each of which is surrounded by 3-4 layers of small differentiated wall cells, the center of the drug chamber is a group of spore-making cells.
spore-forming tissue is polygonal, has a strong cytoste, has a large nucleus, and is easily distinguished from wall cells. Lily spore tissue is a primary spore cell produced by spore cell division, which is formed after several silk divisions. It is then transformed by spore
and
the pollen mother cells enter a minus division.2. At this time in the period of pollen mother cells, the wall layer of flower medicine has been significantly differentiated. The outer outer layer is the surface cortical, under which a larger layer of cells is the pharmaceutical chamber wall (also known as the fiber layer). There are 2-4 layers of middle cells within the wall of the medicine chamber, and from the cross-cutting surface of the drug, the middle cells are flat.
the innermost layer of the flower wall is the velvet felt layer, which is larger, has a strong cytosyte, and extends radially, so it is easy to distinguish from other layer cells. The center of the pollen sac is the pollen mother cell, the cell is nearly circular, has a relatively large nuclea and a strong cytoste. In some permanent productions, pollen mother cells have entered the pre-destriction division phase I. Can be seen chromosomes into fine lines, and see obvious nucleans.3. The two-part and four-part periods are the production of pollen master cells in the process of subtracting. When the pollen mother cell completes the first division of dedated division to form two cells, called the divisive period, when the whole process of de-deflation is completed, four small spores are formed, surrounded by a commonmass wall, called the four-part period.
four subcells of the lily are arranged in a tymological arrangement, and some can also be arranged in a partially symmetrical arrangement. On the permanent production, it can be seen that there are two subcells in the pollen sac, or three or four subcells close together, with a outer tissue. attention to observe the changes in the wall layer of the flower medicine at this time. In the period of divisor and split, the indoor wall and middle layer of lily drug wall remain basically the same, and the velvet layer cells experience the division of the nucleation of the cell nucleo, but not accompanied by the formation of the cell wall, so we can see the phenomenon of the velvet layer cells with double nucleation. 4. Single-core pollen grain period In the single-core pollen grain period, the velvet felt layer cells in the lily drug wall layer begin to degrade, the cell wall disintegates, and the protosites are combined to form a circle. Since then, this poly-core proton group gradually degrades in its place, a degraded form of velvet layer, specially known as adenine velvet layer.
in the pharmacy cavity at this time, four small spores in each of the four parts are released from the walls of the common lycope. After release, the spores continue to develop and grow, forming internal and outer walls and germination holes. As the spores grow, their internal cytostic fluid foaming degree strengthens, forming a large liquid bubble and pushing the nucleus of the cell originally located in the center to one side, the spores mature and are about to enter the stage of male ligation development. Mature spores can also be called single-core pollen particles. 。 5. During the mature pollen grain period, attention was paid to observing the changes in the lily wall layer during this period. When the lily wall layer matures in pollen grains, the velvet layer is generally degraded, while the middle layer is still in the process of degradation. Therefore, in the permanent production, it can be seen that some of the inner walls of the drug still have two or three layers or a flat layer of middle cells, while in others, the middle layer is close to complete disintegyion.
the innerst velvet layer of the wall layer disappears completely at this time, or sometimes a little velvet felt layer is visible after disintegration residue. At this time, the indoor wall of the drug can be clearly seen on the cell wall band uneven thickening. At the same time, the interval between a pair of pollen sacs on both sides of the drug disintegrates and the two chambers are connected to each other.
In addition, at the flower crack, you can see some cells that are different from the skin cells and have a stronger cytokine, which are thin-walled cells developed by the skin cells, called lip cells. Mature flower medicine is finally vertically cracked at the lip cells due to uneven contraction of the fiber layer (the indoor wall of the drug), from which pollen is scattered. lily is a two-cell type, which is formed by a single-core pollen grain that divides silk at once to form two cells. One of the large is a nutritional cell, the other is a spindle-shaped reproductive cell, generally close to the pollen particle wall. Reproductive cells have their own cytostytes, but no cell walls, but instead sink into the cytostytes of nutrient cells.
the outline of the spindle-shaped reproductive cells seen in the permanent production, i.e. the boundary of its mass membrane. The cytoste of mature lily pollen granules contains a large amount of stored substances. The outer wall of the pollen grain has a mesh pattern and a germination ditch. Select all more complete mature pollen grains to be observed under a high-fold object to identify their reproductive cells (generally shuttle-shaped, attached to the side of the pollen grain wall) and nutrient cells. (iii) lily pollen grain overall seal finally, take the whole seal of lily pollen grain for supplementary observation. Lily pollen particles can be seen in yellow, long oval shape. And observe the carvings and germination ditches of the outer wall of pollen grains. 。