advantages of artificial vegetative propagation

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From Wikipedia

Plant propagation

Plant propagation is the process of creating new plants from a variety of sources: seeds, cuttings, bulbs and other plant parts. Plant propagation can also refer to the artificial or natural dispersal of plants.

Sexual propagation (seed)

Seeds and spores can be used for reproduction (through e.g. sowing). Seeds are typically produced from sexual reproduction within a species, because genetic recombination has occurred plants grown from seeds may have different characteristics from its parents. Some species produce seeds that require special conditions to germinate, such as cold treatment. The seeds of many Australian plants and plants from southern Africa and the American west require smoke or fire to germinate. Some plant species, including many trees do not produce seeds until they reach maturity, which may take many years. Seeds can be difficult to acquire and some plants do not produce seed at all.

Electrical propagation

Commonly used by both hobby gardeners, and in large scale industrial facilities, an electrical propagator is a low-cost, efficient and safe method of encouraging seed growth.

Asexual propagation

Plants have a number of mechanisms for asexual or vegetative reproduction. Some of these have been taken advantage of by horticulturists and gardeners to multiply or clone plants rapidly. People also use methods that plants do not use, such as tissue culture and grafting. Plants are produced using material from a single parent and as such there is no exchange of genetic material, therefore vegetative propagation methods almost always produce plants that are identical to the parent. Vegetative reproduction uses plants parts such as roots, stems and leaves. In some plants seeds can be produced without fertilization and the seeds contain only the genetic material of the parent plant. Therefore, propagation via asexual seeds or apomixis is asexual reproduction but not vegetative propagation.

Techniques for vegetative propagation include:

Heated propagator

A heated propagator is a horticultural device to maintain a warm and damp environment for seeds and cuttings to grow in.

This can be in the form of a clear enclosed bin sitting over a hotpad, or even a portable heater pointed at the bin. the key is to keep the moisture in the clear bin, while keeping lighting over the top of it, usually

Seed propagation mat

An electricseed-propagation mat is a heated rubber mat covered by a metal cage which is used in gardening. The mats are made so that planters containing seedlings can be placed on top of the metal cage without the risk of starting a fire. In extreme cold, gardeners place a loose plastic cover over the planters/mats which creates a sort of miniature greenhouse. The constant and predictable heat allows people to garden in the winter months when the weather is generally too cold for seedlings to survive naturally. When combined with a lighting system, many plants can be grown indoors using these mats.


Layering

Layering is a means of plant propagation in which a portion of an aerial stem grows roots while still attached to the parent plant and then detaches as an independent plant. Layering has evolved as a common means of vegetative propagation of numerous species in natural environments. Layering is also utilized by horticulturists to propagate desirable plants.

Natural layering typically occurs when a branch touches the ground, whereupon it produces adventitious roots. At a later stage the connection with the parent plant is severed and a new plant is produced as a result.

The horticultural layering process typically involves wounding the target region to expose the inner stem and optionally applying rooting compounds. In ground layering, the stem is bent down and the target region buried in the soil. This is done in plant nurseries in imitation of natural layering by many plants such as brambles which bow over and touch the tip on the ground, at which point it grows roots and, when separated, can continue as a separate plant. In either case, the rooting process may take from several weeks to a year.

Layering is more complicated than taking cuttings, but has the advantage that the propagated portion can continue to receive water and nutrients from the parent plant while it is forming roots. This is important for plants that form roots slowly, or for propagating large pieces.

Ground layering

Ground layering is the typical propagation technique for the popular Malling-Merton series2 of clonalapple rootstocks in which the original plants are set in the ground with the stem nearly horizontal, which forces side buds to grow upward. After these are started the original stem is buried up to the tip. At the end of the growing season, the side branches will have rooted, and can be separated while the plant is dormant. Some of these will be used for grafting rootstocks, and some can be reused in the nursery for the next growing season's crop.

Air layering

In air layering (or marcotting), the target region is wounded and then surrounded in a moisture-retaining wrapper such as sphagnum moss, which is further surrounded in a moisture barrier such as polyethylene film. Rooting hormone is often applied to encourage the wounded region to grow roots. When sufficient roots have grown from the wound, the stem from the parent plant is removed and planted.It takes about 3 months for the new plant to become mature.



From Encyclopedia

vegetative propagation

vegetative propagation the ability of plants to reproduce without sexual reproduction, by producing new plants from existing vegetative structures. Some plants, such as the Canada thistle and most bamboos, send out long underground stems that produce new plants, often at considerable distances from the original plant. Such plants can form enormous colonies of new plants within a relatively few years. Many trees, such as the beech and aspen, send up root sprouts, and large colonies of new trees thus arise. In other trees, the lower branches may produce roots where they rest upon the ground, and new trees are produced. The leaves of some plants produce buds at their edges, which develop in turn into miniature plants that fall off and take root. Specialists in the fields of agriculture and horticulture take advantage of the regenerative ability of plants through such techniques as the rooting of cuttings; grafting and budding of fruit trees; layering, or inducing the tips of branches to produce new plants; the cutting apart of clusters of perennials , such as rhubarb, into individual plants; the cutting of plants (such as the common potato) into pieces that are then planted separately, each with a bud ( "eye" ); and numerous other techniques. The vegetative propagation of economically important and useful plants is now so widespread that most horticultural varieties are now only reproduced clonally, especially since many of them breed true from seed.


From Yahoo Answers

Question:what is vegetative propagation?what are the advantages of vegetative propagation?-from the chapter reproduction and development in angiosperms

Answers:vegetative propagation, the ability of plants to reproduce without sexual reproduction, by producing new plants from existing vegetative structures. Some plants, such as the Canada thistle and most bamboos, send out long underground stems that produce new plants, often at considerable distances from the original plant. Such plants can form enormous colonies of new plants within a relatively few years. Many trees, such as the beech and aspen, send up root sprouts, and large colonies of new trees thus arise. In other trees, the lower branches may produce roots where they rest upon the ground, and new trees are produced. The leaves of some plants produce buds at their edges, which develop in turn into miniature plants that fall off and take root. Specialists in the fields of agriculture and horticulture take advantage of the regenerative ability of plants through such techniques as the rooting of cuttings; grafting and budding of fruit trees; layering, or inducing the tips of branches to produce new plants; the cutting apart of clusters of perennials perennial, any plant that under natural conditions lives for several to many growing seasons, as contrasted to an annual or a biennial. Botanically, the term perennial Advantages and Disadvantages of Vegetative Propagation Advantages The offsprings are genetically identical and therefore advantageous traits can be preserved. Only one parent is required which eliminates the need for special mechanisms such as pollination, etc. It is faster. For example, bacteria can multiply every 20 minutes. This helps the organisms to increase in number at a rapid rate that balances the loss in number due to various causes. Many plants are able to tide over unfavourable conditions. This is because of the presence of organs of asexual reproduction like the tubers, corm, bulbs, etc. Vegetative propagation is especially beneficial to the agriculturists and horticulturists. They can raise crops like bananas, sugarcane, potato, etc that do not produce viable seeds. The seedless varieties of fruits are also a result of vegetative propagation. The modern technique of tissue culture can be used to grow virus-free plants. Disadvantages The plants gradually lose their vigour as there is no genetic variation. They are more prone to diseases that are specific to the species. This can result in the destruction of an entire crop. Since many plants are produced, it results in overcrowding and lack of nutrients.

Question:

Answers:not having to start from seeds germination process eliminated a good healthy strain can be continued for generations can make as many new plants as wanted/needed cuts down on overall grow/production time

Question:What are the advantages of using soil-less potting mix rather than mineral soil when propagating plants vegetatively?

Answers:It is easier to control things like "damping off" which is a fungal infection which causes the base of the small plant to get soft causing the whole plant to fall over and rot. Damping off is often caused by the soil being too wet. Typical "dirt" contains many very tiny particles which can pack together and not drain well. A special mix can be made to drain well and not drown the little plants. Roots need air to grow well too. Soilless mixes tend to have little fungus and bacteria compared to typical backyard soils which have HUGE amounts. Soilless mixes can even be completely sterile. After the small plant has grown and has enough roots and leaves to live more independently, it can be transferred to a regular soil mix. It is only weak, tender, seedlings and such that really benefit from sterile soilless mixes.You wouldn't want to keep an adult plant in a sterile soilless mix because they do not have the array of minerals needed by the plant to be able to flower or produce fruit. Also, adult plants tend to benefit from the normal array of bacteria and fungi typically found in soils.

Question:I am well aware of the benefits of vegetative propagation in a nursery or other commercial setting, but would there be any advantages of allowing plants to proagate by seed (either directed or just left to do so)?

Answers:Propagating by seed is very cost-effective in that large numbers of uniformly-sized plants can be produced with relatively little effort. A wide selections of seed is available from brokers, and they are less expensive than starters (called liners). Seeds are easy to collect store and ship. However, this method is used commercially only with plants that will come true from seed, that is, reproduce the same characteristics as the source plant. Some species do, and some don't. The trick is in knowing which. Propagation by seed is preferred if the method is appropriate to the species.