What is Micropropagation?
Micropropagation is the fast-vegetative propagation of plants under in vitro states of high light force, controlled temperature, and a defined supplement medium.
The procedure has been applied to a significant number of commercial vegetatively proliferated plant species.
Plants can be proliferated by sexual (through the age of seeds) or asexually (through duplication of vegetative parts) implies.
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Methods of Micropropagation
Micropropagation procedures are of three sorts dependent on the method of engendering: first, the propagation from shoots with cytokinin like benzyl adenine or kinetin; second, various shoot separation from dedifferentiating tissue, callus, with an auxin-like indole acidic corrosive; lastly, the undeveloped organism separation from callus.
The previous two strategies need the establishing procedure with an auxin-like indole acidic corrosive and with naphthaleneacetic corrosive from thereon.
Nowadays, the strategy for propagation from shoots is the most favored one, in light of the fact that the last two strategies present the chance of hereditary variety attributable to the dedifferentiated stage, callus.
Stages of Micropropagation
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Micropropagation is a confusing procedure and essentially includes 3 phases (I, II, and III). A few creators include two additional stages (stage 0 and IV) for an increasingly extensive portrayal of micropropagation.
Stage 0:
This is the underlying advance in micropropagation and includes the choice and development of stock plants for around 3 months under controlled conditions.
Stage I:
In this stage, the inception and foundation of a culture in a reasonable medium are accomplished. Determination of suitable explants is significant. The most normally utilized explants are organs, shoot tips and axillary buds. The picked explant is surface disinfected and washed before use.
Stage II:
It is in this stage, the significant movement of micropropagation happens in a characterized culture medium. Stage II for the most part includes augmentation of shoots or quick incipient organism arrangement from the explant. A development chamber set at 20 - 24 °C is utilized, with a 2000 - to 4000 - lux light force, and a lighting time of 16 hours or something like that.
Stage III:
This stage includes the exchange of shoots to a mode for quick advancement into shoots. Now and then, the shoots are legitimately planted in soil to create roots. In vitro establishing shoots is liked while all the while taking care of countless species.
Stage IV:
This stage includes the foundation of plantlets in soil. This is finished by moving the plantlets of stage III from the research facility to the earth of the nursery. For some plant species, stage III is skipped, and un-established stage II shoots are planted in pots or in the appropriate fertilizer blend.
Advantages of Micropropagation
Plant tissue in limited quantities is adequate for the creation of a huge number of clones in a year utilizing micropropagation. It would require some investment to create an equivalent number of plants utilizing ordinary strategies.
The procedure of micropropagation gives a decent option in contrast to those plant species that demonstrate protection from practices of traditional mass proliferation.
Large measures of plants can be kept up in little spaces. This assists with sparing jeopardized species and the capacity of germplasm.
The expansion of in vitro stocks should be possible whenever of the year. Likewise, a nursery can create natural products, elaborate, and tree species consistently.
Increased yield of plants and expanded force in horticulture species are accomplished.
Fast global trade of plant material without the danger of sickness presentation is given. The time required for isolation is reduced by this strategy.
The micropropagation procedure is additionally valuable for seed creation in specific harvests as the necessity of hereditary protection to a serious extent is significant for seed creation.
With micropropagation having different favorable circumstances over regular strategies for engendering, this strategy holds a better degree and future for the creation of significant plant-based phytopharmaceuticals.
Independent of accessibility of plants, micropropagation offers a worthwhile elective way to deal with customary techniques in creating controlled measures of biochemicals. Hence, extreme and nonstop endeavors in this field will coordinate controlled and fruitful creation of significant, explicit, but unfamiliar plant synthetic concoctions.
The significant impediment in the utilization of micropropagation for some plants is the expense of creation; for some plants the utilization of seeds, which are regularly infection-free and delivered in great numbers, promptly produce plants (see customary seed) in great numbers at a lower cost. Hence, many plant reproducers don't use micropropagation on the grounds that the expense is restrictive. Different raisers use it to create stock plants that are then utilized for seed augmentation.
Mechanization of the procedure could diminish work costs, however, it has demonstrated hard to accomplish, in spite of dynamic endeavors to create mechanical arrangements.
Conclusion:
This article talks in depth about Micropropagation, its methods, and its stages. Students can refer to this document for a thorough understanding of the topic. One can use it for exam purposes.
FAQs on Micropropagation
1. What is micropropagation as per the CBSE curriculum?
Micropropagation is a modern method of plant tissue culture used for the rapid vegetative propagation of a plant. It involves growing plantlets from small pieces of a parent plant, known as explants, in a sterile, in-vitro laboratory environment on a nutrient-rich culture medium. This technique allows for the production of a large number of genetically identical plants in a very short time.
2. What are the main stages involved in the micropropagation process?
The micropropagation process is typically divided into five key stages:
- Stage 0: Selection and preparation of the mother plant. This involves ensuring the stock plant is healthy and disease-free.
- Stage I: Initiation of culture. An explant (like a shoot tip or bud) is taken from the mother plant, surface-sterilised, and placed on a nutrient medium.
- Stage II: Multiplication. The explant is induced to produce a large number of shoots using plant growth regulators like cytokinins.
- Stage III: Rooting. The shoots are transferred to a different medium that encourages root development, forming complete plantlets.
- Stage IV: Acclimatisation. The plantlets are gradually moved from the controlled lab environment to soil or a greenhouse to harden and adapt to natural conditions.
3. What are the key advantages and disadvantages of using micropropagation?
Micropropagation offers several benefits but also has some limitations.
Advantages:
- Allows for the rapid production of millions of clones from a single parent plant.
- Helps in producing disease-free plants, especially when using meristem tip culture.
- Enables year-round propagation, independent of seasons.
- Useful for conserving rare or endangered plant species.
Disadvantages:
- It is a costly process requiring specialised equipment and skilled labour.
- Creates a monoculture, where all plants are genetically identical and thus equally vulnerable to the same diseases.
- There is a risk of somaclonal variations (genetic changes) in some cases.
- Not all plant species can be successfully cultured using this technique.
4. What are some commercially important plants produced through micropropagation?
Micropropagation is widely used in horticulture and agriculture to produce plants of high commercial value. Some common examples include:
- Ornamental Plants: Orchids, Chrysanthemums, and Roses.
- Fruit Crops: Bananas, Strawberries, and Pineapples.
- Plantation Crops: Sugarcane, Potato, and Bamboo.
- Forestry: Teak and Eucalyptus trees.
5. Why is the hardening or acclimatisation (Stage IV) step crucial in micropropagation?
Hardening is a critical step because plantlets grown in-vitro are very delicate. They are raised in a sterile environment with high humidity, controlled temperature, and nutrient-rich media, causing them to have underdeveloped cuticles and poor root systems. The acclimatisation process gradually exposes these plantlets to the harsher, more variable conditions of a natural environment (like lower humidity and non-sterile soil), allowing them to develop the necessary structures for survival and preventing a high mortality rate upon transfer to the field.
6. How does micropropagation contribute to producing disease-free plants?
Micropropagation is highly effective in producing disease-free plants by using the apical meristem as the explant. The meristem, a region of actively dividing cells at the tip of the shoot, is generally free from viruses and other pathogens, even if the parent plant is infected. This is because the rapid cell division outpaces the spread of the virus. By culturing this meristematic tissue, healthy and genetically identical plants can be regenerated, effectively cleaning the plant stock.
7. What is the difference between an explant and a callus in plant tissue culture?
An explant and a callus are two distinct components in plant tissue culture:
- An explant is the small piece of living tissue (e.g., a leaf section, shoot tip, or root segment) that is taken from the parent plant to initiate the culture process.
- A callus is an unorganised, undifferentiated mass of plant cells that is formed when an explant is grown on a specific culture medium containing plant hormones like auxins. It is essentially a clump of cells that can later be manipulated to differentiate into roots, shoots, or entire plantlets.
8. Why are somaclonal variations sometimes considered a disadvantage in micropropagation?
Somaclonal variations are genetic changes that arise during the process of tissue culture, particularly when a callus stage is involved. While these variations can sometimes be a source of new, desirable traits for plant breeders, they are a significant disadvantage when the primary goal of micropropagation is to produce true-to-type, genetically identical clones of a superior parent plant. Unwanted variations can lead to inconsistent quality, poor performance, or loss of the elite characteristics for which the plant was originally selected.
