BIJI DIKOTIL DAN MONOKOTIL

A. BASIC THEORY

1. Understanding dikotil and monocot plants

Magnoliopsida is the name used to replace a name that used older classification systems, class Dicotyledoneae (class "institution of two-leaved plants" or "plant dikotil"). While the monocot plant is a leafy plant single institution.

2. Characteristics and examples of plants and monocot dikotil



In plants class / high levels can be distinguished or divided into two kinds, namely plant seed or a single chip called the monocot / monocotyledonae and plant seed pieces two or also called dikotil / dicotyledonae. The characteristics of monocot plants and dikotil can only be found in plants subdivisions of angiosperms because
it has a real interest



Characteristic differences in monocot plants and dikotil based on distinguishing physical characteristics possessed:

a. Root form

- Monocots: Having a system of root fibers

- Dikotil: Having a root system of helter

b. Form of bone marrow or leaf pattern

- Monocots: Curved or parallel

- Dikotil: pinnate or menjari

c. Kaliptrogen / hood roots

- Monocots: There is a hood root / kaliptra

- Dikotil: There is no root cap

d. The number of pieces of seeds or cotyledons

- Monocots: a piece of fruit seeds alone

- Dikotil: There are two pieces of fruit seeds

e. The content of roots and stems

- Monocots: There is no cambium

- Dikotil: There cambium

f. Number of petals

- Monocots: Generally it is a multiple of three

- Dikotil: Usually a multiple of four or five

g. Protective roots and stems of the institution

- Monocots: Found stem institution / coleoptile and roots of the institution / keleorhiza

- Dikotil: No protective koleorhiza and coleoptile

h. The growth of roots and stems

- Monocots: Can not grow into bigger

- Dikotil: Can grow to be enlarged

Monocot plants are grouped into five tribes, namely:

a. Rumut the grass (Graminae), ex: corn, rice

b. Pinang-proposal (Palmae), ex: coconut, sago

c. Banana-Pisangan (Musaceae), ex: bananas, king

d. -Angrekan orchids (Orchidaceae), ex: orchid, vanilla

e. Gingers (Zingiberaceae), ex: ginger, turmeric

Plants dikotil dikelaompokan into 5 tribes, namely:

a. Distance-jarakan (Euphorbiaceae), ex: distance, yams, rubber

b. Legumes (Leguminoceae), ex: bananas, beans

c. -Terungan eggplant (Solanaceae), ex: eggplant, peppers, tomatoes

d. Cashew-jambuan (Myrtaceae), ex: guava, rose apple

e. Composite (Compositae), ex: sunflower


B. Germination

Germination (germination Ing.) is the initial stage of development of a plant, especially seed plants. In this stage, the embryo inside the seed which was originally located in the dormant condition experience a number of physiological changes that cause it to develop into young plants. Young plants is known as the sprouts.

Sprouts are plants (sporophytes) youth who had just grown from embryonic stage in the seed. This is called germination stage of development and is a critical stage in plant life. Sprouts are usually divided into three main parts: the radicle (embryonic root), hipokotil, and cotyledons (leaves the institution). Two classes of flowering plants are distinguished from the chopped leaves of the institution: monocot and dikotil. Seed plants is more varied in chopped open institution. Sprouts pine for example can have up to eight leaves the institution. Several types of flowering plants have no cotyledons, and called akotiledon.

Sprouts are often used as food and are classified as vegetables. Khazanah Asian cuisine known sprouts as part of the menu is quite common. Sprouts said healthy food because it is rich in vitamin E but also criticized because some antigizi sprouts forming substances. Sprouts are known as the malted barley is used as a raw material of beer. Malt is also used as part of a healthy drink because it contains maltose lower calories than sucrose.

Germination begins with water uptake from the environment around the seeds, including land, air and other media. The observed changes is the growing size of the seed called imbibisi stage (means "drink"). Seeds absorb water from the surrounding environment, both from land and air (in the form of dew or moisture. The effect is the growing size of the seed because of cell biology. Embryonic cells enlarged and softened seeds.

The presence of water inside the cell activates a number of enzymes early germination. Fitohormon absisat acid levels decreased, while gibberellins increases. Based on the study of gene expression in the model plant Arabidopsis thaliana is known that the germination loci that regulate embryo maturation, such as ACID ABSCISIC insensitive 3 (ABI3), fusca 3 (FUS3) and LEAFY COTYLEDON 1 (LEC1) decreased its role (downregulated) and vice versa loci that promote germination increased role (upregulated), such as GIBBERELIC ACID 1 (GA1), GA2, GA3, GAI, ERA1, street vendors, SPY, and Sly. Note also that in the normal process of germination of a group of transcription factors that regulate auxin (called Response Factors auxin, ARFs) suppressed by miRNA. Changes this control to stimulate cell division in the active conduct of mitosis, such as at the end of the radicle. Consequently radicle size bigger and the skin or shell of urgency from the seeds, which eventually burst. At this stage the necessary prerequisite that the shells of the seeds are soft enough for the embryo to split (http://www.wikipedia.com/perkecambahan.)


2. Tools and Materials

And tools and materials in practical anatomy and germination dikotil and monocot namely, pencils, ballpoint, cutter, magnifying glass, like a seedling, sand, water faucets, yells, pengaris, erasers, and paper HVS.


3. Implementation Procedures

a. Anatomy

o Setting up equipment and materials

o Splitting the seeds in a state of transverse and longitudinal

o Observing the anatomical structure as a whole, halved crosswise and longitudinal monocot seeds (maize, rice and palm oil) dikotil (peanuts, beans, green beans and soybeans)

o Draw the whole beans, halved crosswise and lengthwise inside the paper HVS

o Examined by the practicum supervisor


b. Germination

o Setting up equipment and materials

o Observing the results of the germination of monocot seeds (maize, rice and palm oil) dikotil (peanuts, beans, green beans and soybeans) during semainggu later in the paper menggambarakannya HVS.

o Examined by the practicum supervisor


C. RESULTS AND DISCUSSION

1. Anatomy

From the results of the anatomy lab and monocot plants dikotil obtained that seed dikotil and monocot plants have parts that seed food reserves, seed coat, epikotil, cotyledons, and radikuala hipokotil. Except for the palm oil have flesh, seed coat and embryo.

According Sutopo (2002), parts of the seed consists of three basic parts:

1. Embryo

The embryo is a new crop came from the unification of male gametes and female in a process of fertilization. Perfect development of the embryo that consists of the following structures: epikotil (candidate shoots), hipokotil (candidate stem), cotyledon (leaf candidate) and radicle (potential root). Plants in the class Angiospermae classified by the number of cotyledons. Monokotiledon plants have one cotyledon for example: grass and onions. Dikotiledon plants have two cotyledons for example nuts sedangakan on the class of gymnosperms generally have more than two cotyledons such as pine, which has up to 15 cotyledons. In grasses (grasses) cotyledons which is called scutellum, embryonic buds called plumulle covered by a protective upih called the coleoptile, while at the bottom of the embryonic root is called ridiculous that is covered by a protective upih called coleorhiza.


2. Network storage of food reserves

In seeds there are some structures that can serve as a network storage of food reserves, namely:

a. Kotoledon, such as in nuts, watermelon and pumpkin.

b. Endosperm, eg on maize, wheat, Cereal and other groups. On the inside the coconut is white and can be eaten is endospermnya.

c. Perisperm, eg in the family Chenopodiaceae and Caryophyllaceae

d. Gametophytic female haploid gymnosperms such as in a class of pine.

Food reserves stored in seeds are generally composed of carbohydrates, fats, proteins and minerals. The composition and the percentage varies depending on the type of seeds, eg sunflower seeds are rich in fat, nuts seeds are rich in protein, rice seeds contain lots of carbohydrates.


3. Protective seed

Seed may consist of a protective seed coat, the remnants of the nucleus and the endosperm, and sometimes the fruit. But generally seed coat (testa) is derived from the modified ovule integument during seed formation takes place. Usually the outer skin of beans hard and strong brown while the inside is thin and webbed. Seed coat serves to protect the seeds from the drought, mechanical damage or attack of fungi, bacteria and insects.

In the case of the use of food reserves there are some differences between the sub-class monokotiledon and dikotiledon where in:

• Sub kleas monokotiledon: new food reserves in the endosperm are digested after the seeds mature and dikecambhakan and has absorbed water. Examples of corn, rice, wheat.

• Subclass dikotiledon: food reserves contained in kotileodon or perisperm already digested and absorbed by the embryo before the seeds mature. Examples of nuts, sunflower and pumpkin.


C. Germination

Seed germination in plants that do dikotil namely maize and rice, while in seeds dikotil are: peanuts, beans, soya beans and green beans. maize seed on the first day already showed swelling of rice while the swelling is shown on the second day. On the second day of corn has emerged roots and shoots, while the rice on the third day. This type of germination in plants is the type hipogeal.

Seeds from a plant of slow dikotil perkecambahnnya namely peanuts, where at age 7 days showed just 1.5 cm long radicle. Green Beans showed the fastest germination at age 7 days to reach 10 cm and 2 leaves. Perkecambhan on the plant type is the type dikotil epigeal germination.

According Sutopo (2002) type is where the emergence of epigeal germination followed by a prolonged hipokotil radikel as a whole and brings with cotyledons and plumula into the ground. While the type in which the emergence radikel hipogeal followed by lengthening plumula, hipokotil does not extend to the upper surface of the soil while the cotyledons remain in the seed coat below the soil surface.

The process of seed germination is a complex series of morphological changes, fisologi, and biochemistry. The first stage begins with a seed germination process of water absorption by seeds, seed and skin softening hydration of protoplasm. The second stage begins with the activities of cells and enzymes as well as rising levels of seed respiration third stage is the stage where there is the decomposition of materials such as carbohydrates, fats and proteins into forms that dissolve and ditranslokasikan to the points grow. The fourth stage is asimililasi of materials that have been described earlier in the meristematic region to generate new energy. Formation activities of components and new cell growth. The fifth stage is the growth of the sprouts through the process of division, enlargement and division of cells grown at these points. While the water absorption by seeds occurred in the first stage usually lasts until the network has a moisture content of 40-60% (or 67-150% on dry weight basis). And will increase again at the time of radicle emergence through a network storage and sprouts that are growing have kandunga water 70-90%. Metabolism of the cells begin to absorb water after the reaction-reaction that include reform commonly called catabolism and synthesis components for growth is called anabolism. This metabolic process will continue and is a supporter of the growth of sprouts to mature plants.

In the process of germination there are several factors that affect the factors within and outside factors. Factor in include: the level of seed maturity, seed size, dormasni, and germination inhibitors. While external factors include: water, temperature, oxygen, light and medium.

Seed maturity level. Seeds are harvested before physiological maturity level is reached, does not have high viability, even in some kind of seed plants thus will not be able to germinate. In guessing at the level of the seeds have not had adequate food reserves and also the formation of an embryo going perfectly.

Seed size: in jaringaa penyimpananya seeds have carbohydrates, protein, fat and minerals. Where these materials are needed as raw materials and energy during germination. Is assumed that the seeds are large and heavy food reserves contain more than a small, perhaps a larger embryo. Seed size showed a positive correlation of protein content in sorghum seeds, the bigger / heavy seed size the greater the protein content.

Dormancy: a dormant seed when the seed is said to be actually viable (alive) but will not germinate even if placed in circumstances that qualify for perkecambahannya. This dormancy period can last for seasonal or it could be for several years, depending on the type of seeds and types dormansinya. Dormancy can be caused by several factors, among lin: impermiabilitas seed coat well on gas or because of resistance to the effects of mechanical seed coat, embryo rudiameter, dormnsi secondary and materials germination inhibitors. But with the special treatment of dormant seeds can be stimulated to germinate, for example: treatment stratification, soaked in laruta sulfate, and others.

Germination inhibitors: many substances that are known to inhibit the germination of seeds are: a solution with high osmotic level, eg a solution of mannitol, saline, substances that interfere with the trajectory of metabolism, herbicide, auxin, coumarin and materials contained in the fruit.

Water: Water is a necessary condition for the process of germination. Two fakor affecting water absorption by seeds is the nature of the seed itself, especially the skin protector and short of water available in the surrounding medium. The amount of water required varies depending on the type of seed. But generally does not exceed two or three times that of dry weight. Tingakat water uptake is also influenced by temperature, high temperatures cause meningkatknya kebutuha water.

Temperature: the temperature is an important requirement both for seed germination. The optimum temperature is most favorable temperature for the unfolding of germination. In this temperature range have the highest percentage of germination. The optimum temperature for most seeds seeds between 26.5 - 35oC. Beneath it on the lowest minimum temperature of 0 - 5oC most types of seeds will fail to germinate or damage resulting in abnormal formation of sprouts.

Oxygen: the process of respiration will take place during seed still alive. At the time of germination takes place the process of respiration will increase accompanied by meningakatnya oksogen retrieval and release of carbon dioxide, water and energy in the form of heat. Lack of oxygen can be used will result in delays in the process of seed germination.

Light: the relationship between the effect of light and seed germination is controlled by a system known as phytochrome pigment composed of the chromophore and protein. Chromophore part is sensitive to light. Kedaan dikecambahakan seed in the dark can produce sprouts that have etiolasi the occurrence of an abnormal elongation at hipokotil or epikotilnya, pale and weak sprouts.

Medium: a good medium for germination must have good physical properties, friable, has the ability to store water and free from major disease-causing organisms of fungi "damping of". Sandy soil with clay texture and are equipped with organic ingredients is a good medium for the sprouts that ditransplantingkan to the field. Sand can be used as a medium dipersemaian. The physical condition of the soil is very important for the continuity of life germinated into mature plants. The seeds will be hampered perkecambahnnya on solid ground, because the seed struggled to penetrate into the soil surface. In addition to the medium, the level of seed planting depth may also affect seed germination. It also has a close relationship with the physical condition of the soil. In loose soil a little seed planted in will not much affect the germination. In contrast to the more solid ground where the seed should not be planted too deep to facilitate seedling emergence to plant surfaces. Tatapi must remember not to plant the seed too shallow.


D. DAFTA REFERENCES

http://www.wikipedia.com./perkecambahan


http://www.wikipedia.com./kecambah



Sutopo, L. 2002. Seed Technology. Malaysia: Faculty of Agriculture UNBRAW