PRACTICUM REPORT OF PLANT PHYSIOLOGY

GERMINATION AND DORMANCY

BY

GROUP 4

Diska Alfionita D. (11317244014)

Chairunisha Dianing T. (11317244015)

Soraida Afni Y. (11317244017)

INTERNATIONAL BIOLOGY EDUCATION

DEPARTMENT OF BIOLOGY EDUCATION

FACULTY OF MATHEMATIC AND SCIENCE

YOGYAKARTA STATE UNIVERSITY

2012

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A. OBJECTIVE

1. To know some kind of seed germination responses to environmental factors (water,

temperature, light, chemicals, etc.).

2. To know the rate of seed germination by skin thickness.

3. To know the limits of the water needs in the germination of a seed.

B. BASIC THEORY

1. GERMINATION

Germination by an expert is a protrusion of root morphological changes such

institutions (radicle). For a farmer, is the emergence of seedling germination.

Technically, germination is the beginning of the emergence of active growth that

produces seed coat fragments and seedling emergence (Dahlia, 2001: 101).

According Suyitno (2010:51), germination is a process in which the radicle

(embryonic root) extends outward through the seed coat. Behind the appearance of

symptoms radicle morphology, the physiological processes occur-biokemis

complex, referred to as a physiological process of germination. Physiologically, the

process of germination takes place in several stages following important:

1. Water absorption

2. Metabolic breakdown of food reserve material

3. Transport material to the breakdown of the endosperm embryo actively growing

4. The process of re-forming process new materials

5. Respiration

6. Growth

Seeds will be grown in the fruit. Once of ripe fruit and seeds removed, usually

seeds dormant for long or short. This means that although the seeds are getting

enough water and good conditions to conduct germination, the seed will not

germinate. Dormancy can be caused by the formation of chemical compounds

inhibiting the grain surface, the lack of antigens that are important or caused by a

hard seed coat so that water and oxygen can not enter. Dormancy can be removed in

various ways such as by freezing, extend the period of cooling, extended exposure to

the cold, provide high humidity in the presence of oxygen, intensive warming up

(burned), through the gut of birds or mammals, is done mechanically (sanding, split),

or left overgrown mushrooms (Dradjat Sasmitamihardja, 1996: 366).

If the conditions necessary to eliminate dormancy is running, the embryo will begin

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to make gibberellins and cytokinins, which is needed to surpass the growth

inhibitory effects of employment (growth inhibitor) so that growth can begin. If at

that time, given the seed water it will sprout (Dradjat Sasmitamihardja, 1996: 367).

Many of the factors that control seed germination process, both internal and

external. Internally the germination process is determined by the balance between

promoters and inhibitors of germination, particularly gibberellin acid (GA) and

abskisat acid (ABA). External factors in the process of germination include water,

temperature, humidity, light, and the presence of certain chemical compounds that

act as inhibitors of germination (Suyitno, 2010:51-52).

According Dahlia (2001: 101-102), an early and intermediate fitohormon

germination processes are important for some growth hormone activity. Fitohormon

include:

1. Gibberellins which serves to activate hydrolytic enzymes in digestion.

2. Cytokines function to stimulate cell division that emerged roots and shoots

institutions institutions. Expansion in koleoriza (root tip) appears due to

cell enlargement.

3. Auxin serves to enhance the growth due to enlargement koleoriza, roots

organizations and institutions shoots and genotyping activities (orientation

on the growth of roots and shoots is true regardless of the orientation of the

seed).

Water is an important factor in the process of seed germination, because

before the process of seed germination in the state dehydrated. Normally seeds

contain approximately 5-20% of the total weight, so that before the process of seed

germination begins to absorb water. The early stages of germination was taking

water rapidly, called imbibition. There are indications that up to a certain critical

moisture content, grain growth will not occur. If water is removed before it reaches a

critical point, then the seeds will not be damaged. However, when the critical

threshold has been passed and metabolism has started, the seeds were germinated it

will mangalami death when dried again (Dradjat Sasmitamihardja, 1996: 367).

Peak occurs imbibition on lettuce seeds for 2 hours, while respirasinya occurred

after 2 hours in and reached the first peak after hours-8. respiration both started at

the 16th and reached a maximum after 24 hours. Two peaks are considered related to

chemical hydrolysis and synthesis. Mitosis pins at the 12th and reached a peak at the

16. Ontogeny germination followed two distinct metabolic phases, ie the enzymatic

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hydrolysis of food reserves stored, and the synthesis of new tissue from the

hydrolyzed compounds such as sugars, amino acids, fatty acids, and minerals are

released (Dahlia, 2001: 101).

In addition to water, oxygen is also a critically important factor in the

germination process. Metabolic rate of early germination performed anaerobically,

but after the seed coat rupture and oxygen diffuses into the germination continued

aerobically. In addition, the right temperature is also required in the process of

germination. Seeds usually will not germinate below a certain temperature that is

specific to a species (Dradjat Sasmitamihardja, 1996: 367-368).

Light is also essential for the germination of some seeds. Small seeds that have

only very little food reserves to support the growth of the early embryo

memerluakan perubahanuntuk are autotrophs. If the seeds are planted too deep in the

ground, it will run out of food before reaching the surface reserve tana, and sprouts

are likely to die because they do not have time photosynthesize. For the seeds of a

group like this, the light is very important that germination should occur on the

surface or near the surface. In addition, the merupakna ditokrom pigment sensitive to

light plays an important role in the germination of seeds of certain species (Dradjat

Sasmitamihardja, 1996: 367).

Germination (Germination Ing.) is an early stage of development of a plant,

especially the seed plants. In this stage, the embryo in the seed which was originally

located on a dormant condition experience a number of physiological changes that

cause it to develop into a young plant. Young plants are known as sprouts. Sprouts is

a plant (sporophyte) young newly developed from the embryonic stage in the seed.

Stage of development is called germination and is a critical stage in the life of plants.

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: monocots and dikotil. Seed

plants open more varied in chopped institution. Sprouts pine for example can have

up to eight leaves the institution. Some flowering plants have no cotyledons, and

called akotiledon. (Wikipedia, sprouts: 29/11/2008)

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source : http//perkecambahan.wikipedia.wiki.id

Germination begins with the uptake of water from the environment around the seeds,

good soil, air, and other media. The change observed is the growing size of the so-called seed

imbibition phase (meaning "to drink"). Seeds absorb water from the surrounding

environment, both from land and air (in the form of dew or moisture. Effect that occurs is due

to the growing size of the seed [[{cell biology) | cell]] enlarged embryo cells) and beans

soften. The process is purely physical. The presence of water in the cells activates a number

of enzymes early germination. Fitohormon abscisic acid levels decreased, while gibberellin

increases. Based on the study of gene expression in the model plant Arabidopsis thaliana is

known that the germination loci regulating embryo maturation, such as abscisic acid

insensitive 3 (ABI3), fusca 3 (Fus3), and Leafy cotyledon 1 (LEC1) decreased role

(downregulated) and vice versa loci that promote germination increased role (upregulated), as

GIBBERELIC ACID 1 (GA1), GA2, GA3, GAI, ERA1, street vendors, SPY, and SLY. It is

well known that in the normal germination process a group of transcription factors that

regulate auxin (called Auxin Response Factors, ARFs) suppressed by miRNA control change

stimulates 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 the pressed seeds, which eventually

broke. At this stage the necessary prerequisites that shell beans are soft enough for the

embryos to be broken. (wikipedia, germination: 29/11/2008)

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source : http//perkecambahan.com

2. DORMANCY

Dormancy can be defined as a state of latent growth and metabolism, which

can be caused by either environmental conditions or by a factor of the plant itself.

The network had failed to grow despite the often dormant in a state of ideal (Dradjat

Sasmitamihardja, 1996: 399).

Delayed growth or resting state is a condition that lasts for a limited period

and, despite ongoing state support for germination. Technically, when the dormant

seed is physically or physiologically separated from the parent plant. Dormancy ends

when conditions favorable for pertumbuahan. Kuiesen (not moving) is a descriptive

term for a break because the seeds are less conducive to a germination (growth ripen

in storage). Dormant seeds are seeds that failed to germinate when placed in an

environment that supports other plant seed germination (Dahlia, 2001:106).

Dormancy is a mechanism to defend itself against very low temperatures

(freezing) in the winter, or a drought in the summer which is an important part in the

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life of a plant, dormancy must be running at the right time, and break free or break it

when the conditions are possible to initiate growth (Dradjat, 1996: 399).

Dormancy is not only pentidakaktifan metabolic processes, but also often

involves the development of organs or specialized materials. Many complex events

associated with dormancy, such as aging, and threshing the leaves on the trees.

Dormancy is a programmed developmental events memerlukann specific

metabolism to stop metabolic activity. (Dradjat, 1996: 400).

Dormancy occurs in many forms. Many seeds dormant for a period of time

after leaving the fruit. Trees shed their leaves to avoid danger at the time the air

became cold and dry and the ground freezes. Many tunmbuhan wet, the top die

during the winter or drought, while the part that is under the ground like a bulb,

kormus, bulbs remain alive but dormant (Dradjat, 1996: 399).

According to Dahlia (2001:107), dormancy class include:

1) young embryo, as in Orchidaceae sp.

2) seed skin-tight, as in Leguminoseae impervious to water, and are impervi-

ous to O2 Graminae.

3) Skin mechanically resistant seeds, as in certain species of Graminae and

species that have shaped hard shell nuts.

4) Physiological, has a wide range of species, the seeds contain growth inhibit-

ors or stimulants supply growth in the embryo sac, seed coat, or husk that are

not important enough to go through the process of germination materials.

The process to be able to germinate can be obtained through the maturation of

the parent plant, drying in storage, or simply aging in dry storage. Instead there was a

prolonged cooling demand or set of conditions, such as temperature changes, radi-

ation cycle, the salt, bleaching, or removal of the husk. However, these treatments

are only effective for the seeds soak up water (Dahlia, 2001:107).

According to Dradjat (1996: 400), There are three factors that can lead to

dormancy, namely:

1) Environmental factors

One important factor that stimulates dormancy is fotoperioda. Day (short day)

stimulates many timber plants become dormant. In this case the response of the

inflorescence, leaves must be induced to produce inhibitor (inhibitor) or hormones

are transported to the shoots and inhibits growth. This inhibition can be removed by

an induction day (long day) or by giving gibberellic acid (Dradjat, 1996: 400).

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Basically cooling itself, is not important in inducing dormancy, and dormancy

will not be induced by the presence of a short day when the temperature is too low to

carry out an active metabolism. However, the reality shows that cooling is an

essential precondition for the opening dormancy (Dradjat, 1996: 400-401).

The state of water shortage is an important thing that can cause dormancy in

some plants, especially in dormancy to survive in dry or hot conditions. In addition,

kekeurangan nutrient especially nitrogen is also a cause of dormancy in some plants

(Dradjat, 1996: 401).

2) Abscisic acid (ABA)

Various symptoms of dormancy and aging that can be induced by

administering ABA, which maintains dormancy, inhibits germination, inhibit the

synthesis of enzymes in gibberellin-induced seed, inhibits flowering, bud abortion,

abortion fruit, leaf aging, accelerate abscission, shoot bud formation in 'shoot' , the

formation of side shoots, reduced cell division, induced biochemical changes that

lead to aging and leaf abscission (Dradjat Sasmitamihardja, 1996: 402).

3) The interaction of ABA with other growing substance

Giving ABA should continue to be maintained in order to keep the effect.

When granting the ABA stopped, the growth and metabolism will be active again. It

is caused by several substances that stimulate the growth will mengantagonis ABA

effect. Gibberellic acid is one of the causes of the ABA mengantagonisan. If the

organs are dormant stored in a dark place and extract the ABA, then the introduction

of a high concentration of GA though not be overcome inhibition by ABA. In these

circumstances, the provision of kinetin may counteract the effects of ABA and GA

may stimulate germination (Dradjat, 1996: 402).

The relationship between GA with ABA is inversely proportional. GA can

stimulate long day plant (long day plant) flowering, while the ABA gives the

opposite effect. Although ABA may stimulate flowering day (short day plants), but

these hormones exert a different and opposite and not always mengantagonis each

other (Dradjat, 1996: 402-403).

Growth and synthesis of -amylase and inhibited by ABA, but the effects of

the barriers will disappear by giving GA, kinetin or benzyladenine. Dormancy is

usually associated with a short (short day), while the release of dormancy associated

with (long day). This was due to long and short days related to an alleged fitikrom

control agent (Dradjat, 1996: 403).

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a. Seed Dormancy

The simplest example of the dormancy is a hard seed coat that prevents the

absorption of oxygen or water. A hard seed coat commonly found in members of

the family Fabaceae (Leguminosae), except for peas and beans. In some species,

water and oxygen can not penetrate certain seeds because the entrance blocked by a

stopper such as a cork (stopper strofiolar) in a small hole (aperture strofiolar) in a

nut shell. When the seeds shaken-shaken, sometimes lock off so that germination

can take place. The treatment is called shocks (Salisbury, 1995: 197).

Solving barrier called the seed coat scarification or scratching using knives,

files, and sandpaper. In nature scratches can occur due to work microbes, whereas

the experts use alcohol or other solvents to eliminate fat waxy substance that

sometimes hinder water to enter (Salisbury, 1995: 197).

If the seeds are removed from the fruit, dried, and planted, the seed will soon

germinate. Osmotil potential in fruit juice too negative for germination. In addition,

there is a specific inhibitor such as ABA in the endosperm of the seed growing

alfalfa, which serves as a barrier to embryo germination (Salisbury, 1995: 198).

Germination inhibitors are not only found in the seeds, but also in the leaves,

roots, and other plant parts. When carried out plants or released during litter

decomposition, compounds that can inhibit perkecambahab alelopati seed or root

development around the parent plant (Salisbury, 1995: 198).

The embryos of some species grow very rapidly by transferring carbon and

nitrogen compounds from food storage cells during initial cooling. Inhibitor lost

during initial cooling, and the hormonal triggers such as gibberellins or cytokinins

grow pooled. Initial cooling can increase the potential untum synthesize

gibberellins. Auxin does not significantly affect the germination, but often replace

all cooling gibberellin (Salisbury, 1995: 199-200).

b. Bud dormancy

Bud dormancy almost always develops before the formation of colors in the

fall and drying leaves. Buds of various trees stop growing in the middle of summer,

sometimes going back showed slight growth in late summer before entering into

full dormancy in the fall. Flower buds that will grow the following season usually

form on the fruit trees in the middle of summer. Green leaves and will be actively

farmed until the early fall when the leaves begin to dry up during the day in

response to a short, clear, and cold. Along with the loss of chlorophyll, yellow and

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orange carotenoid pigments become visible, and anthocyanin synthesized. The fruit

is often cooked during this time. Resilience frost also formed in response to low

temperatures and short days (Salisbury, 1995: 200).

Unavailability of water often accelerates the formation of dormancy, as the

limited mineral nutrients especially nitrogen. It is important for species that enter

dormancy before terjadinay high temperatures and drought in the tropics or arid

climates. The establishment is known for its dormancy in response to changes in

day length and temperature changes in the soil (Salisbury, 1995: 201).

Bud dormancy dormancy precede the last part true and it can be easily

reversed by moderate temperature and day length. However, efforts to

mengindukdi secarartahap active growth failure and then plants achieve true

dormancy that requires special treatment to end (Salisbury, 1995: 201).

Morphology plays an important role in the phenomenon of dormancy.

Dormant buds usually have a very short segments and typically leaves turn called

bud scales. Scales prevents drying, blocking heat loss for a while, and restrict the

movement of oxygen into meristem below. Bud scales are also responsive to light

mempunai space and other functions (Salisbury, 1995: 201).

Treatment of some chemical compounds in the bud dormancy can end. As 2-

kloroetanol (ClCH2CH2OH) are often called ethylene klorohidrin has been used

for many years. When administered in the form of steam, this compound may

terminate dormancy of fruit trees. Another treatment is by soaking plant parts in a

tub of warm water 40oC to 50oC for 15 seconds. Pemebrian gibberellin end bud

dormancy in many plant-leaf fall, will also end the dormancy of seeds that require

low temperatures, and causes flowering in plants that require low temperatures

(Salisbury, 1995: 202).

Experts fisiolologi seed germination is usually set as a series of events

beginning with the end in view of imbibition and radicle (root institutions, or on

some seeds, cotyledon / hipokotil) or emerged through the skin lengthwise grain.

(Bew and Black, 1982.1984; Mayer, 1974). Seeds can remain viable (alive), but

was unable to germinate or grow for several reasons: external conditions or

conditions in an easy to understand is an embryo that has not reached the maturity

to be able to germinate morphology (eg on some members Orcidaceae). Only time

that allowed this growing maturity. (Silasbury & Ross: 1995, p 194)

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To distinguish between these different circumstances, seed physiologists use

the two terms: Kuisen, the seeds when conditions are not able to bekecambah

simply because the conditions outside are not appropriate (eg, seeds are too dry or

too cold), and dormancy of the seeds that failed to germinate conditions because

conditions in, although external conditions (eg temperature, humidity, and

atmospheric) is appropriate. (Silasbury & Ross: 1995, p 194-195)

There is a problem with that nomenclature. Dormant seeds to germinate is

often induced by changes in the environment, such as light or low temperature

period. Where can we draw the line on the conditions stated as "appropriate

external conditions"? LGI also there is the sense that the conditions inside that is

always a barrier. (If water is limiting, then there is shortage of water in the seed

embryo cells adlam.) In other words, beyond simply allowing germination

conditions by affecting the conditions inside. We're even more correct to say the

basic conditions rather than to rely on the word appropriate. So we can call as a

condition of seed dormancy when seeds fail to germinate though: There are quite a

lot of moisture out, beans paired to a common set of atmospheric conditions on the

ground, and the temperature is in the range typically associated with physiological

activity. (Silasbury & Ross: 1995, p 195)

B. Classification of Seed Dormancy

Seed dormancy associated with efforts to delay seed germination, until the

time and environmental conditions makes it possible to carry out the process.

Dormancy may occur in the seed coat and embryo. Seeds are ripe and ready to

germinate and need a place to grow climatic conditions suitable to break dormancy

and begin the process of germination. Pretreatment scarification used to break seed

coat dormancy, while stratification is used to overcome embryo dormancy.

Dormancy is classified into various categories based on the causes,

mechanisms and forms. (Http / / dormancy and seed germination: 29/11/2008)

a. Based on the factors causing dormancy

1. Imposed dormancy (quiscence): obstruction of active growth due to

unfavorable environmental conditions

2.Imnate dormancy (rest): dormancy caused by circumstances or conditions

in the organs of the seeds themselves

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b. Based on the mechanism of seed dormancy in

1. The physical mechanism

An inhibitory mechanism of dormancy due to seed the organ itself; divided

into:

1. Mechanical: the embryo does not develop because of limited physical

2. Physical: water absorption disrupted due to the impermeable seed coat

3. Chemistry: the seed / fruit contains a chemical inhibitor

3. Mechanism of physiological

Dormancy is caused by the occurrence of resistance in physiological

processes; divided into:

1. Photodormancy: physiological processes in seeds is hampered by the

presence of light

2. Immature embryos: physiological process is hampered by the condition of

the seed embryo is not / not yet ripe

3. Thermodormancy: physiological processes in seeds hampered by

temperature

c. Based on the form of dormancy

       Seed coat impermeable to air/O2

1. Part impermeable seed: membrane seeds, seed coat, nucellus, pericarp,

endocarp

2. Impermeability can be caused by the deposition of an assortment of

substances (eg cutin, suberin, lignin) in the membrane.

3. Hard seed coat which can be caused by genetic and environmental

influences. Seed coat dormancy breaking can be done by mechanical scarification.

4. Part seeds that regulate the entry of water into the seed: mikrofil, nut shell,

raphe / hilum, strophiole; as for higroskopiknya mechanism governed by the hilum.

5. O2 turnover caused by the mechanism of the seeds in a nut shell.

Dormancy for O2 entry and exit barriers through a nut shell it can be broken by

high-temperature treatment and delivery of powerful solutions.

Immature embryos (immature embryo)

1. When there abscission (abscission of the fruit from the stem), the embryo

still has not completed its development phase. Eg: Gnetum gnemon (melinjo)

2. Embryos have not differentiated

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3. The embryos are morphologically well-developed, but it still takes time to

achieve the perfect shape and size.

         Because immature embryo dormancy can be broken by a low

temperature treatment and chemicals. (Http / / dormancy and seed germination:

29/11/2008)

Seeds require post-harvest ripening (afterripening) in dry storage

Afterripening dormancy because the need for this can be broken by high-

temperature treatment and stripping the skin.

Seeds need low temperatures

Species common in temperate regions, such as apples and Familia Rosaceae.

Dormancy is naturally occurs in a way: seeds dormant during the fall, winter

exceed one, and only germinate the following spring. Dormancy because seeds will

need a low temperature can be broken by giving low-temperature treatment, the

provision of aeration and imbibition.

The characteristics of seeds that have dormancy are:

4. if the skin is peeled, the embryo grows

5. embryo dormancy experience that can only be broken by low temperatures

6. embryos are not dormant at low temperatures, but the seed germination

process still requires a lower temperature

7. germination occurs without giving a low temperature, but seedlings grow

dwarf

8. roots come out in the spring, but the new epicotyl out next spring (after

exceeding the winter)

Seeds are light sensitive

Light affects germination in three ways, namely the intensity (quantity) of

light, light quality (wavelength) and fotoperiodisitas (long day).

High-intensity light can enhance germination in seeds positively photoblastic

(germination accelerated by light), if high intensity radiation is given in a short

duration of time. This does not apply to seeds that are negatively photoblastic

(germination inhibited by light).

Seeds positively photoblastic stored in conditions of imbibition in the dark

for a long period of time will become unresponsive to light, and this is called

skotodormant. In contrast, seeds that are negatively photoblastic be photodormant

when subjected to light. Both dormancy can be broken by low temperatures.

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Germination is causing the red area of the spectrum (red; 650 nm), whereas

the infrared (far red; 730 nm) inhibit germination. The effects of these two regions

in the spectrum are mutually antagonistic (completely contrary): if given

alternately, the effects that occur later influenced by the spectrum of the last given.

In this case, the seed has two pigments photoreversible (can be in 2 alternate):

P650: absorb in the red and P730: absorb in the infrared region

If the seeds are light red (red; 650 nm), the P650 pigment was changed to

P730. P730 that produces a series of actions that lead to germination. Conversely,

if the P730 is the infrared (far-red; 730 nm), the pigment turns back to P650 and

terhambatlah germination process. (Http / / dormancy and seed perkecanbahan:

29/11/2008)

Photoperiodisitas

Response of seed photoblastic influenced by temperature:

1. Giving temperature 10-200C: seeds germinate in the dark

2. Giving temperature 20-300C: seeds require light to germinate

3. Giving temperature> 350C: inhibited seed germination in the dark or light

The need light for germination can be replaced by the temperature changed.

The need for light to breaking dormancy can also be replaced by chemicals such as

KNO3, thiourea and gibberellin acid.

Dormancy as inhibitors

Seed germination is the culmination of a series of complex metabolic

processes, each of which should take place without interruption. Each one of the

substances that inhibit the process will result in delays in the whole process of

germination. Several inhibitors in seeds that have been successfully isolated and

was soumarin lacton unsaturated;, but the location is difficult to determine because

inhibitory different work area where the substance is isolated. Inhibitor may be

present in the embryo, endosperm, seed coat and pulp. (Http / / dormancy and

germination: 11/29/2008)

Examples are easy on dormancy is a hard seed coat that blocks the absorption

of oxygen or water. A hard seed coat was commonly found in members of the

family Fabaceae (leguminoseae), although not found in beans or peas, which shows

that dormancy is not common in the cultivated species. In some species, water and

oxygen can not penetrate certain seeds because the entrance blocked by a stopper

such as a cork (stopper strofiolar) in a small hole (aperture strofiolar) in a nut shell.

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When the seeds being shaken, sometimes lock it off so it can take germination. It's

called shock treatment, and has been applied to the seed Meliotus alba (sweet

clover), Trigonella arabica, and Crotallaria egyptica. (Silasbury & Ross: 1995, p

197)

Seed dormancy experiencing is usually caused by: low / no water imbibition

process caused by the structure of the seed (seed coat) is hard, making it difficult to

exit the entry of water into the seed. , Respiration are confused, because the

membrane or the pericarp in the seed coat that is too loud, so that the air exchange

in the seed becomes obstructed and causes low metabolism and mobilization of

food reserves in the seed. , The mechanical resistance of the seed coat embryo

growth, because a nut shell is strong enough that hinder the growth of the embryo.

In food crops, seed dormancy often found in rice, whereas dormasni vegetables

common in white cucumber seed, melon and watermelon non seed. (dormansi :

29/11/2008)

C. PROCEDURE

1. Materials

a. Seeds thin-skinned:

1. Green beans (Phaseolus radiatus)

2. Red beans

b. Seeds thick skin:

1. Tamarind (Tamarindus indica)

2. Flamboyant (Delonix regia)

2. Tools

a. Cotton and distilled water

b. Fluorescent light / UV

c. Low incubator

d. NaCl

e. Herbicide

3. Cara kerja

Prepare four petri dish or other places as a breeding material 2 different groups of

one seed (thin skin and thick skin)

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Prepare four sets of treatments for both types of seeds, four of media are given two

pieces of filter paper and then etched with 2 ml of PEG.

D. RESULT AND DISCUSSION

Pada percobaan kali ini kami melakukan pengamatan perkecambahan pada biji

bung matahari. Ada dua jenis biji bunga matahari yang digunakan yaitu biji bunga

matahari yang muda dan biji matahari yang sudah tua. Tumbuhan yang masih kecil,

belum lama muncul dari biji , dan masih hidup dari persediaan makanan yang terdapat

dalam biji, dinamakan kecambah.

Pada waktu biji berkecambah, tumbuhan kecil yang dihasilkan belum mampu

mencari makanan sendiri, dan masih tergantung dari persediaan makanan yanga terdapat

dalam biji tumbuhan kecil ini disebut kecambah (plantula).

Perkecambahan biji dapat dibedakan dalam dua macam:

a. Perkecambahan diatas tanah, yaitu tipe perkecambahan, karena terjadi

perbentangan ruas batang dibawah tanah lembaga, dan daun lembaga terangkat keatas.

Muncul diatas tanah. Misalnya pada kacang hijau. Daun lembaga biasanya berwarna

hijau, dan kemudian gugur, sementar itu sudah terbentuk daun-daun normal.

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Placing 20 new seed grain into 2 petri dishes and 20 long grain seeds into 2 petri

dish.

Leaving the seeds in the media for one week.

After one week, did removing by replacing media with 2 filter paper soaked 2 ml

distilled water (aquades).

Planting seeds that have germinated by using soil

b. Perkecambahan dibawah tanah, bila daun lembaga tetap tinggal didalam biji.

Biji akan berkecambahan bila terpenuhi syarat-syarat yang diperlukan yaitu air,

udara, cahaya, dan panas. Jika syarat-syarat tersebut tidak terpenuhi tumbuhan baru yang

ada pada tumbuhan biji berada dalam keadaan tidur. Dalam keadaan ini lembaga dapat

hidup bertahun-tahun tanpa kehilangan daya tumbuh. Tetapi ada pula biji-biji sebelum

berkecambah memerlukan waktu untuk istirahat. Sebelum waktu istirahat terpenuhi, biji

tidak akan berkecambah, walau syarat-syarat perkecambahat terpenuhi. Gejala ini

dikenal dengan nama dormansi.

Biji sebagian besar spesies didaerah dingin mengalami dorman atau kuisen selama

musim dingin. Perubahan tertentu terjadi didalam sel biji sel tersebut yang

memungkinkannya bertahan pada suhu dibawah titik beku.

Perkecambahan biji tidak hanya dipengaruhi oleh suhu tapi juga oleh cahaya,

pemecahan kulit biji agar radikula dapat menerobos keluar oksigen dan /atau air dapat

masuk, penghilangan zat penghambat kimiawi, dan pematangan embrio, tapi tak mampu

berkecambah atau tumbuh karena beberapa alasan: kondisi luar atau kondisi dalam.

Situasi dalam yang mudah dipahami adalah embrio yang belum mencapai kematangan

morfologi untuk mampu berkecambah.

Biji dorman sering diinduksi untuk perkecambah oleh beberapa perubahan khusus

dilingkungan, seperti cahaya atau periode suhu rendah.

Biji bunga matahari yang muda dan yang sudah tua diberi perlakuan yang sama

yaitu diberikan PEG. Biji ditutup rapat dan disimpan selama 4 hari sebelum di priming.

Setelah itu, biji di priming dan diberi air untuk memicu terjadinya dormansi pada biji

dan didapatkan hasil sebgai berikut : pada biji bunga matahari yang masih muda terjadi

perkecambahan. Hal tersebut dikarenakan air yang diberikan pada biji sehingga memicu

aktifnya hormone dan terjadinya perkecambahan pada biji binga matahari muda,

sedangkan pada biji matahari yang tua tidak terjadi perkecambahan. Hal ini dikarenakan

masa simpan biji yang terlalu lama dan kondisi biji yang sudah rusak.

E. CONCLUSION

1. Environmental conditions with adequate moisture content will accelerate the

process of germination. These chemicals can accelerate the rate of germination, but

may also inhibit. It depends of the type of seeds that germinated. Some kind of seed

germination responses to environmental factors have a certain optimum point, which

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means at the point of optimum germination can take place properly. An optimum

point to environmental factors (temperature, water, light, chemicals,) at different

specific seed.

2. Germination rate is very dependent on the thickness of the seed coat, because

it affects the absorption process. The thinner seed coat the faster the process of

germination, so conversely the thick seed coat, the more slowly also the rate of

germination process.

3. In the process of germination, water too little or too much will inhibit the

germination of some types of seeds such as mung beans, lentils, seeds and seeds

flamboyant acid water demand in the germination process has a certain amount,

which is an excellent number in state media wet / damp, called the optimum point.

F. DISCUSSION

Question:

1. Look at the graphics power of germination and germination rate between treatment

units. Consider the power of germination between dry - moist / wet - Soak seeds in

each group and between groups also try to compare seeds thin and thick skin. Which

group showed the greatest germination and which groups are the smallest? Why?

2. What the conclusion?

Answer:

1. The group that showed the greatest germination seeds is a group that has a thin

seed, because it is easier and faster to absorb water. While that showed the lowest

germination the seeds are thick skinned, because it is difficult to absorb the water.

Seed group showed the greatest power is the seed medium moist / wet. This happens

because in the process of germination occurs from the absorption of water into the

seed. Balanced with the need of water for germination. While in dry media

germination does not occur, because if there is no water available (medium dry)

then it does not happen the water absorption and germination does not occur, nor if

the availability of excess water (submerged media) there will be absrobsi excess

water from the environment when in germination only requires a certain amount of

water, so the excess water will cause the seeds rot.

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2. The conclusion that can be taken from the experiment this time is as follows:

the environmental conditions with adequate moisture content will accelerate the

process of germination. These chemicals can accelerate the rate of germination, but

may also inhibit. It depends of the type of seeds that germinated.

1. Increasingly thin seed coat, the faster the rate of germination, and conversely

the thick seed coat, the more it will slow the rate of germination

2. In the process of germination, water too little or too much will inhibit the

germination of some types of beans such as mung beans, red beans, tamarind

seeds and seed of flamboyan.

G. TUGAS PENGEMBANGAN

Pertanyaan

1. Morphological characteristics which indicate the presence of germination?

2. During germination takes place physiologically, the process what happens to these

sprouts?

3. Does a seed have a certain tolerance limits of various ecological factors germination,

including the need for water?

4. What the meaning of dormancy, and what factors are causing symptoms the

dormant?

Jawaban

1. Morphological characteristic were easily seen when germination was radicle

discharge events or embryonic root that penetrates the seed coat, followed by

elongation of the radicle proficiency level and is accompanied by the emergence of

a candidate stem, root hairs and leaves candidates first.

2. Physiologically, the process of germination takes place in several stages is

important as following: 1) Absorption of water, 2) Metabolism solving food reserve

material, 3) Transport material to the breakdown of the endosperm actively growing

embryo, 4) The process of re-forming process new materials, 5) Respiration, and 6)

Growth.

3. Yes, the seeds have a certain tolerance limits for germination ecological factors,

including the need for water. If a grain surplus or shortage of water, the seeds will

not grow.

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4. Dormancy can be defined as a state of latent growth and metabolism, which can be

caused by either environmental conditions or by a factor of the plant itself. There

are three factors that can lead to dormancy, namely: 1) environmental factors, 2)

abscisic acid (ABA), and 3) the interaction of ABA with other growth substances

Dormancy is a resting phase or inactive phase of growth and development that

occurs in plants. Factors affecting dormancy is the absence of water, the hormone

abscisic system, thickness, and a nut shell.

H. REFERENCES

Dahlia. 2001. Fisiologi Tumbuhan. Malang: Jica.

Dradjat Sasmitamihardja, dkk. 1996. Fisiologi Tumbuhan. Bandung: Jurusan Biologi

FMIPA ITB

Salisbury, Frank B dan Cleon W Ross.1995. Fisiologi Tumbuhan. Bnadung : ITB.

Suyitno. 2010. Petunjuk Praktikum Fisiologi Tumbuhan Dasar. Yogyakarta : Jurdik

Biologi FMIPA UNY.

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