what is ment by allelopathy/?

Question

plants want to live in their space alone.

Answer 1

The word allelopathy derives from two separate words. They are allelon which means "of each other", and pathos which means "to suffer". Allelopathy refers to the chemical inhibition of one species by another. The "inhibitory" chemical is released into the environment where it affects the development and growth of neighboring plants.



Allelopathic chemicals can be present in any part of the plant. They can be found in leaves, flowers, roots, fruits, or stems. They can also be found in the surrounding soil. Target species are affected by these toxins in many different ways. The toxic chemicals may inhibit shoot/root growth, they may inhibit nutrient uptake, or they may attack a naturally occurring symbiotic relationship thereby destroying the plant's usable source of a nutrient.

How Plants Guard Their "Personal Space" with Poisons?
Have you ever felt like you needed your own space? Sometimes we all need to be alone. Plants and trees need to have their own space, too. How do you get your own space? You can walk away or shut your door, but what can plants do? They can't walk or run anywhere. Plants have a different way of getting their own space. They use allelopathy.
Allelopathy is a chemical process that a plant uses to keep other plants from growing too close to it. Some plants that use allelopathy are black walnut trees, sunflowers, wormwoods, sagebrushes, and trees of heaven.

Some pine trees are allelopathic. When its needles fall onto the ground, they begin to decompose . The soil absorbs acid from the decomposing needles. This acid in the soil keeps unwanted plants from growing near the pine tree.

Impact of allelopathy
Do you know what the ground under a pine tree looks like? Have you ever noticed that no plants grow underneath pine trees? This happens because the pine needles that cover the ground keep other plants from growing. The pine needles contain acid which goes into the soil when the needles start to decompose. This doesn't hurt the pine tree, but kills other plants.
When we begin to learn more about allelopathy, we can find healthier herbicides and pesticides , to kill specific unwanted plants and insects, but not kill the plants we want.

Allelopathy is a form of chemical competition. The allelopathic plant is competing through "interference" chemicals. Competition, by definition, takes one of two forms--exploitation or interference.



Competition is used by both plants and animals to assure a place in nature. Plants will compete for sunlight, water and nutrients and, like animals, for territory. Competition, like parasitism, disease, and predation, influences distribution and amount of organisms in an ecosystem. The interactions of ecosystems define an environment.



When organisms compete with one another, they create the potential for resource limitations and possible extinctions. Allelopathic plants prevent other plants from using the available resources and thus influence the evolution and distribution of other species. One might say that allelopathic plants control the environments in which they live.

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http://en.wikipedia.org/wiki/Allelopathy

Answer 2

The term allelopathy denotes the production of specific biomolecules by one plant that can induce suffering in, or give benefit to, another plant. However, it is most commonly used in the former sense - an interaction in which one plant causes suffering to another plant.

Conceptually, biomolecules (specifically termed allelochemicals) produced by a plant are released into the environment and subsequently influence the growth and development of neighbouring plants. It is important to keep in mind that allelopathy involves the addition of a chemical compound or compounds (secondary metabolites) into the environment, while "competition" involves the removal or reduction of some factor or factors in the environment (such as nutrients, water, or light).

Although allelopathic science is a relatively new field of study, there exists convincing evidence that allelopathic interactions between plants play a crucial role in both natural and manipulated ecosystems. These interactions are undoubtedly an important factor in determining species distribution and abundance within some plant communities. Allelopathic interactions are also thought to be an important factor in the success of many invasive plants

Answer 3

The term allelopathy denotes the production of specific biomolecules by one plant that can induce suffering in, or give benefit to, another plant. However, it is most commonly used in the former sense - an interaction in which one plant causes suffering to another plant.

Conceptually, biomolecules (specifically termed allelochemicals) produced by a plant are released into the environment and subsequently influence the growth and development of neighbouring plants. It is important to keep in mind that allelopathy involves the addition of a chemical compound or compounds (secondary metabolites) into the environment, while "competition" involves the removal or reduction of some factor or factors in the environment (such as nutrients, water, or light).

Although allelopathic science is a relatively new field of study, there exists convincing evidence that allelopathic interactions between plants play a crucial role in both natural and manipulated ecosystems. These interactions are undoubtedly an important factor in determining species distribution and abundance within some plant communities. Allelopathic interactions are also thought to be an important factor in the success of many invasive plants.

Answer 4

The word allelopathy derives from two separate words. They are allelon which means "of each other", and pathos which means "to suffer". Allelopathy refers to the chemical inhibition of one species by another. The "inhibitory" chemical is released into the environment where it affects the development and growth of neighboring plants.
Allelopathic chemicals can be present in any part of the plant. They can be found in leaves, flowers, roots, fruits, or stems. They can also be found in the surrounding soil. Target species are affected by these toxins in many different ways. The toxic chemicals may inhibit shoot/root growth, they may inhibit nutrient uptake, or they may attack a naturally occurring symbiotic relationship thereby destroying the plant's usable source of a nutrient.
Some plants that use allelopathy are black walnut trees, sunflowers, wormwoods, sagebrushes, and trees of heaven.
Some pine trees are allelopathic. When its needles fall onto the ground, they begin to decompose . The soil absorbs acid from the decomposing needles. This acid in the soil keeps unwanted plants from growing near the pine tree.

Allelopathy is a form of chemical competition. The allelopathic plant is competing through "interference" chemicals. Competition, by definition, takes one of two forms--exploitation or interference.
Competition is used by both plants and animals to assure a place in nature. Plants will compete for sunlight, water and nutrients and, like animals, for territory. Competition, like parasitism, disease, and predation, influences distribution and amount of organisms in an ecosystem. The interactions of ecosystems define an environment.

Answer 5

Eric T. Zinn, Teacher of Biology & Environmental Sciences

Brooklyn Technical High School

29 Fort Greene Place, Brooklyn NY 11217

[phone], Ext 551

Allelopathy

Allelopathy is relatively new as a science, even though statements were made about the phenomenon over 2000 years ago. The term was coined by Molisch [in] 19371 to refer to biochemical interactions between plants of all kinds, including microorganisms typically placed in the plant kingdom. These microorganisms include, of course, many microscopic algae, fungi, and bacteria. Molisch indicated in his discussion that he meant the term to include stimulatory as well as inhibitory biochemical interactions. Fortunately, most scientists involved in research in allelopathy around the world have followed Molisch’s definition of the term. Only a few scientists in the United States have deviated from his terminology.

It is important to keep in mind that allelopathy involves the addition of a chemical compound or several chemical compounds to the environment, while competition involves the removal or reduction of some factor in the environment, factors like water, minerals, food, and light. Muller (1969)2 recommended use of the term interference to refer to the overall influence of one plant on another. This interference would include both allelopathy and competition. Since it is still impossible to eliminate allelopathic effects in so-called competition experiments, all such studies should be termed interference experiments. Those readers desiring to learn more about the historical development of allelopathy should read at least the first chapter of Rice (1983). 3

An Investigation of the Anti-Microbial Effects of

Common Spices on Three Species of Bacteria.

[A Micro-Biological Investigation

conducted at Pace University)

by Eric T. Zinn and Noemi Rodriguez]

Introduction

Throughout history spices have been used as food preservatives. This may be based on the fact many plants contain phytotoxins which they use to defend themselves against invasion by microorganisms and to avoid inter and intraspecies competition. This phenomenon is known as allelopathy. "Allelopathy involves the addition of a chemical compound or several chemical compounds to the environment Allelopathy may possibly explain the food preservation properties of many spices. To test our hypothesis we chose four spices, Red Pepper, Garlic, Sage, Black Pepper, to determine their effect on three species of bacteria, Escherichia coli, Enterobacter aerogenes, and Bacillus cereus.

Hypothesis

Red pepper would have a preferential inhibitory effect on the growth of bacteria compared to Garlic, Sage, and Black Pepper.

Procedure

1. Pre-prepared nutrient agar was heated in a water bath to a 100 degrees C. for 5 minutes, and poured into three petri dishes. Each petri dish contained 20 ml of nutrient agar. The petri dishes were allowed to cool to 45 degrees C. and harden.

2. Pippeted a small amount of one of the three bacterial cultures to a petri dish. The culture was spread over the surface of the agar with an "L-shaped" glass rod. This was done for each of the remaining cultures. Between inoculations the glass rod was sterilized with 95% ethyl alcohol.

3. Each of the petri dishes had introduced a small amount of the actual four spices, and allowed to incubate for 48 hours at room temperature, +/- 21 degrees C.

Observations

At the end of the incubation period the petri dishes were examined, and it was found that the greatest anti-microbial activity was at the site of the Garlic in the cultures of Escherichia coli and Enterobacter aerogenes. Garlic had no observable "zone of inhibition" on B. cereus. There were no observable "zones of inhibition" for any of the other spices.

Results

On the E. aerogenes the "zone of inhibition" for Garlic was 4.25 mm. On the E. coli the "zone of inhibition" was 0.5 mm.

Conclusion

Our hypothesis was proven incorrect. The results indicated that Red Pepper does not exhibit a preferentially inhibitory effect on these bacteria. Search of the literature indicates that many members of the Allium spp. have strong anti-microbial effects. Examples of the Allium genus are Garlic, Onion, Chives, and Leeks. Members of this group contain complex sulfur compounds which are the active chemicals in their anti-microbial properties.


Spices on Nutrient Agar

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The 4 Spices on Nutrient Agar showing Inhibitory effects on the Bacterial Cultures.