Micropropagation vs Tissue Culture
The fundamental difference between micropropagation and tissue culture is that the micropropagation is a method of tissue culture. Tissue culture is a technique that is used to propagate plants in large quantities in relatively short period. Micropropagation is a method that comes under tissue culture and it is used to produce clones of mother plants.
What is Tissue Culture?
Plant tissue culture can be described as cultivation or growing of plant cells, tissues, organs, and plantlets on artificial medium under sterile / aseptic and controlled environmental conditions in vitro. Tissue culture relies on the principle known as totipotency. That is, each cell has the genetic capability to grow into a full organism when there are optimum environmental conditions for the growth. There are various methods to culture plants in aseptic conditions. Some of those include,
Seed and seedling culture – growing of seeds in vitro artificial medium under aseptic conditions. This method increases the efficiency of seed germination that are difficult to germinate in vivo. E.g. Orchids.
Embryo culture – growth of embryos that are taken out of the seeds in an artificial medium. This method helps to overcome seed dormancy, latent period of seed and to study embryo development.
Organ culture – any part of the plant such as, shoot tips, roots, leaf part, anther, or ovary can be used to regenerate new plants. This method produces clones of the mother plant.
Orchid tissue culture
What is Micropropagation (Clonal Propagation)?
Micropropagation is a method of plant tissue culture. This involves, multiplication of genetically identical individuals (clones) by asexual means such as somatic tissues or organs. This can be achieved by the organ culturing methods that comes under tissue culture. The conventional methods of micropropagation include planting of cuttings, layering, splitting, grafting, etc. Both the conventional and novel methods of micropropagation produce clones of the mother plant.
General steps involved in micropropagation are; establishment, multiplication, transplantation and acclimatization.
• Establishment: selection of proper or disease-free plant material and introducing it to an artificial growth medium. This growth medium contains sucrose as the energy source, plant hormones, and micro-nutrients as growth supplements and agar as the growth substrate.
• Multiplication: from single explants hundreds to thousand plantlets can be produced by multiplication.
• Transplanting and acclimatization (hardening): plants with developed roots and shoots will be first transplanted in greenhouse conditions and then they will be planted in normal environmental conditions.
Rose plant grown by micropropagation
What is the difference between Micropropagation and Tissue Culture?
When considering the methods of plant tissue culture and micropropagation, they both show more similarities than differences.
• Production of clones by micropropagation and production of either clones or genetically different plants by other methods of tissue culture can be considered as the major difference between the two methods.
Similarities between Micropropagation and Tissue Culture
• Large number of plants can be reproduced in a small area.
• Less time-consuming.
• Very small piece of plant is required to initiate the growth. E.g. leaf part, anther.
• Since plants can receive optimum amounts of nutrients and controlled environment conditions in vitro propagation is faster than in vivo propagation methods.
• Applicable for many species that are hard to multiply in vivo. E.g. Orchids.
• Since explants are free from diseases progeny plants are also healthy.
• Both the methods are invaluable to conserve rare, and threatened plant species.
Drawbacks of Micropropagation and Tissue Culture
• Due to humid environment morphological, anatomical, and physiological and metabolic activities can be altered. E.g. poor differentiation of mesophyll tissue results in chlorophyll deficiency.
• Although environmental conditions are controlled there is a chance of contaminations by bacteria, fungi, virus, and mites.
• Phenolic exudates can cause browning of explants.
• High cost to provide nutrients, environmental conditions, equipment, and chemicals.
• Necessity of trained staff.
Images Courtesy:
- Orchid tissue culture by ProjectManhattan (CC BY-SA 3.0)
- Rose plant grown by micropropagation via Wikicommons (Public Domain)
