micropropagation

Micropropagation is a set of plant tissue culture techniques used to rapidly multiply clones of a plant under sterile conditions. It enables production of large numbers of uniform plants from small amounts of starting material, such as shoot tips, leaves, or embryos. The process typically uses a nutrient medium with a carbon source and plant growth regulators, and is performed in controlled environments to minimize contamination.

A typical cycle includes initiation, multiplication, elongation, and rooting. During initiation, explants are sterilized and placed on medium to stimulate shoot formation, often with cytokinins. In multiplication, shoots are subcultured to generate many shoots. Elongation promotes shoot growth, followed by rooting on an auxin-rich medium. The plantlets are then acclimatized to non-sterile greenhouse or field conditions. Modern scale-up methods may use bioreactors or temporary immersion systems to increase throughput.

Types of micropropagation include axillary bud culture, meristem culture (used for virus-free propagation), organogenesis, and somatic embryogenesis. Meristem culture is particularly valuable for producing virus-free plant stock. Micropropagation can, however, lead to somaclonal variation with extended culture, and requires careful management of culture conditions to maintain genetic fidelity.

Applications and advantages: rapid multiplication of elite genotypes, production of disease-free material, year-round propagation, and you can achieve uniform plant sets for commercial production. It is widely used in horticulture, forestry, conservation of endangered species, seedless fruit production, and plant breeding. Limitations include high initial capital and operating costs, dependence on sterile facilities, specialized technical expertise, and potential genetic changes during prolonged culture.