Asexual Reproduction in Plants



1, Introduction


Asexual reproduction is a method of reproduction where offspring arise from a single parent and only inherit that parents genes.[1] Many different seed plants use one of a variety of asexual methods to reproduce.(1) They find these processes advantageous for a number of reasons; far less energy required, stable environments means variability is not as essential, they do not have the trouble of finding a mate and the list goes on.(1) If the environment is

Figure 1. (1)
Figure 1. (1)

particularly harsh, the more delicate or susceptible organs or stages of sexual reproduction may not be able to survive.(1) Many plants which inhabit such areas as deserts or arctic tundra only reproduce asexually.(1) In this wiki page, various types of asexual reproduction will be examined. Figure 1 depicts some of the methods of asexual reproduction that will be discussed throughout this page:


2. Rhizomes



This horizontal, underground plant stem is capable of producing the shoot and root system of a brand new plant.(1) Plants that have the ability to preform this include; grasses, cattails and sedges.(1) These stems will grow through the soil and eventually produce adventitious roots and a new above ground shoot.(1) However a new separate plant will be formed if the rhizome dies off.(1) Figure 2 and 3 show plant reproduction using rhizomes:


Figure 2: Plant Asexual Reproduction with the use of Rhizomes. (1)
Figure 2: Plant Asexual Reproduction with the use of Rhizomes. (1)

Figure 3: The Cycle of a Rhizome
Figure 3: The Cycle of a Rhizome

3. Stolons (Runners)

Figure 2: Runners active in Asexual Reproduction in Plants. (1)
Figure 2: Runners active in Asexual Reproduction in Plants. (1)


Stolons are also horizontally growing stems, however they produce a very small amount of leaves.[2] These plants will develop adventitious roots deep into the soil where a leaf would normally produce a node.(2) This is where new above ground shoots is made.(2) Examine the runner and new shoots in figures 4 and 5:

Figure 4: Illustrates the Process of Reproduction using runners.(1)
Figure 4: Illustrates the Process of Reproduction using runners.(1)


4. Bulbs

Asexual reproduction bulbs are plant bulbs that do not use insects to pollinate them, instead they produce another plant by cloning a piece of their genetics.[3] Bulbs have short stems that are covered by fleshy leaves that collect and store nutrients during the winter.(1) Once the weather becomes milder in the spring, the shoot apex starts to grow using the stored nutrients in the leaves.(2) Onions, chives and lilies are examples of asexual reproduction using bulbs.(1) Refer to figures 6 and 7 to outline the process of bulb reproduction:
Figure 6: Characteristics of a Bulb. (1)
Figure 6: Characteristics of a Bulb. (1)

Figure 7: Examples of Bulb Plants. (3)
Figure 7: Examples of Bulb Plants. (3)

5. Plantlets

Plantlets use a process in which miniature plants grow on the margin of their leaves and eventually break off and develop into mature plants.
Figure 9: The Plantlet is still Attached to its Parent Plant.(1)
Figure 9: The Plantlet is still Attached to its Parent Plant.(1)

(1) It will remain attached and obtain food from its parents plant until the plantlet is officially established as a new plant.[4] Some seed plants such as the duckweed and Kalanchoe use this method to reproduce asexually.(1) The duckweed, which is an aquatic plant, reproduces almost entirely by this method.(1) Figures 8 and 9 show plantlets in action:
Figure 8: Duckweed is found in swampy areas.(4)
Figure 8: Duckweed is found in swampy areas.(4)



6. Corms

Figure 11: This Crocus Flower has its corms showing at the bottom of its stem.(5)
Figure 11: This Crocus Flower has its corms showing at the bottom of its stem.(5)


A corm is a firm, swollen stem located underground where food is stored for the plant.(1) The growth cycle of a corm is very unique compared to the other methods. A mature corm will wither and die after growing for a year, it is then replaced by a new corm that will proceed to grow on top of the old corm.[5] Corms and bulbs are more less the same except for the fact that corms do not have fleshy leaves surrounded by them and bulbs store their nutrients in their leaves while corms store them in the swollen stem.(1) Examples of plants grown from corms are crocus and gladiola.(1) Corms are shown in figures 10 and 11:
Figure 10: Exemplifies the Old and New Corms. (5)
Figure 10: Exemplifies the Old and New Corms. (5)















7. Tubers
A tuber is used as a method of asexual reproduction by most plants that form tubers.[6] Tubers are commonly eaten by species because of their stored energy, such as a potato.(6) There are two forms of tubers: stem tubers, and root tubers. Stem tubers form from rhizomes that were mentioned earlier.(6) When the
Figure 13: Plant Reproductive by the use of Tubers.(1)
Figure 13: Plant Reproductive by the use of Tubers.(1)

root swells or buds, root tubers are formed.(6) It is easily understandable why a parent plant would chose to store its nutrients in a tuber.(6) By keeping this storage of energy underground, a plant can ensure that it can easily be accessible in the future.(6) When the parent plant dies off, the tuber will helpfully step in and propagate some new plants.(6) Tubers are developed when specialized stem branches grow down into the ground and absorb starch containing cells.(6) Buds on the tubers will grow into the new plants.(1) Plant reproduction using tubers is illustrated in figures 12 and 13:
Figure 12: Example of Root Tubers.(6)
Figure 12: Example of Root Tubers.(6)





8. Plant Asexual Reproduction in the Media

http://esciencenews.com/articles/2010/03/08/asexual.plant.reproduction.may.seed.new.approach.agriculture

For hundreds of years farmers have spent too much money on seeds for their crops.[7] $36 billion was the estimated amount of money spent on these seeds
throughout the world yearly.(7) Since sexual reproduction eases many of the specifically selected traits for these seeds, farmers cannot grow them themselves.(7) As a result, farmers must purchase new supplies of these seeds every year.(7) Some plants such as dandelions can actually reproduce asexually by cloning themselves.(7) So what if some of these seeds that are in high demand could produce asexually; clone themselves. This is exactly what scientists have been urgently studying.(7) Throughout this article, Jean-Philippe Vielle-Calzada, an international research scholar explains his research and discoveries. Vielle-Calzada and his colleagues have reported that they have moved a step closer to turning sexually-reproducing plants into asexual reproducers, a finding that could have profound implications for agriculture.

This article relates to asexual reproduction in plants because scientists around the world are trying to incorporate this method of reproduction into society. It requires less energy and is the future of plant reproduction.


9. Glossary

Adventitious Roots - These roots are found in unusual places, they originate from stem or leaf tissue, often where a branch or other part contracts soil or damp material.[8]

Node - The point on a plant stem from which the leaves or lateral branches grow.(8)

Root System - The configuration of a plant's various roots.(8)

Shoot System - The aerial portion of a plant body, consisting of stems, leaves, and (in angiosperms) flowers.(8)


10. References
  1. ^
    http://kentsimmons.uwinnipeg.ca/16cm05/16labman05/lb4pg6.htm
  2. ^
    http://www.buzzle.com/articles/asexual-reproduction-in-plants.html
  3. ^ http://www.ehow.com/video_4993259_asexual-reproduction-bulbs.html
  4. ^
    http://www.gardeningknowhow.com/indoor/plantlets-on-houseplants.htm
  5. ^
    http://plantpropagation.com/corms.htm
  6. ^ http://www.wisegeek.com/what-is-a-tuber.htm
  7. ^
    http://esciencenews.com/articles/2010/03/08/asexual.plant.reproduction.may.seed.new.approach.agriculture
  8. ^
    http://dictionary.reference.com/