Model Answer
0 min readIntroduction
Micropropagation, also known as tissue culture, is a technique of rapidly multiplying plant material to produce a large number of progeny using a small piece of parent plant tissue under sterile, controlled conditions. This method, pioneered by George Steward and Millard Shirley in the 1930s, has revolutionized horticultural practices, particularly for plants that are difficult to propagate through conventional methods. The increasing demand for disease-free and genetically uniform plants, coupled with the need for rapid multiplication, has fueled the widespread adoption of micropropagation globally. It’s a critical component of modern horticulture and biotechnology.
What is Micropropagation?
Micropropagation is an in vitro propagation technique. It involves taking a small piece of plant tissue (explant) – such as a shoot tip, bud, or leaf – and placing it in a nutrient-rich medium under aseptic (sterile) conditions. The explant undergoes cell division and differentiation, leading to the formation of a mass of undifferentiated cells called a callus. This callus is then stimulated to regenerate into plantlets, which are subsequently acclimatized to field conditions. The entire process is carefully controlled for factors such as light, temperature, humidity, and nutrient availability.
Advantages of Micropropagation
Micropropagation offers several significant advantages over traditional propagation methods:
- Rapid Multiplication: It allows for the rapid production of a large number of plants in a short period, often within weeks, compared to months or years required for conventional propagation.
- Disease-Free Plants: The sterile environment minimizes the risk of disease transmission. Furthermore, techniques like meristem culture can be used to eliminate viruses and other pathogens from the explant.
- Genetic Uniformity: Micropropagation produces clones, ensuring genetic uniformity and consistency in traits like flower color, fruit size, and yield.
- Year-Round Propagation: It is independent of seasonal constraints, enabling year-round production of planting material.
- Conservation of Rare Species: Micropropagation is crucial for conserving endangered or rare plant species by providing a means of mass propagation from limited germplasm.
- Production of Virus-Free Planting Material: This is particularly important for crops like banana and potato, which are often affected by viral diseases.
Utilization in Horticultural Crops: Examples
Micropropagation has found extensive application in a wide range of horticultural crops. Here are a few examples:
- Banana: Micropropagation is extensively used for producing disease-free banana plants, particularly to combat Fusarium wilt (Panama disease). The Cavendish variety, which constitutes a significant portion of global banana production, is almost entirely propagated through micropropagation.
- Strawberry: Strawberry plants are rapidly multiplied through micropropagation, ensuring uniform fruit quality and disease resistance. Varieties with specific flavor profiles or disease resistance are readily propagated.
- Orchid: Exotic orchids, known for their complex propagation challenges, are successfully propagated through micropropagation, making them more accessible to consumers. Dendrobium and Phalaenopsis are common examples.
- Apple & Pear Rootstocks: Micropropagation is employed to produce large quantities of disease-free rootstocks for fruit tree propagation. This ensures uniformity in the orchard and facilitates grafting.
- Rose: Micropropagation allows for the rapid multiplication of rose varieties, ensuring the availability of high-quality, disease-free planting material.
| Crop | Micropropagation Application |
|---|---|
| Banana | Disease-free plant production (Fusarium wilt) |
| Strawberry | Rapid multiplication, uniform fruit quality |
| Orchid | Propagation of difficult-to-propagate varieties |
| Apple/Pear | Rootstock production for fruit tree orchards |
Conclusion
Micropropagation represents a significant advancement in horticultural practices, enabling rapid multiplication, disease elimination, and genetic uniformity in plant production. Its versatility and efficiency have made it indispensable for a wide range of horticultural crops, contributing to increased productivity and improved plant quality. As biotechnology continues to evolve, further refinements in micropropagation techniques are expected to enhance its efficiency and expand its applicability, addressing the growing demand for high-quality planting material globally. Continued research into optimizing media and protocols will be key.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.