There are two ways that plants can reproduce:
Sexual reproduction leads to offspring that are better adapted to the environment. However, asexual reproduction is generally preferred when we need to produce identical plants with desired characteristics.
For example, if we want a specific shade of pink flowers, asexual reproduction can give us our desired characteristic. This process is also called cloning and the genetically identical offspring are called clones.
Although genetic engineering has given us a variety of ways to clone plants, we will discuss two simple methods for cloning:
Taking cuttings is one of the simplest methods to produce identical plants quickly and cheaply. Gardeners have been using this method for a long time to grow plants with desirable characteristics.
It involves cutting a part of the plant (preferably a growing shoot, or branch) and planting the cutting in fertile compost. Basic environmental needs such as adequate sunlight and water also need to be met. Soon, the cutting grows into a new plant that is genetically identical to the parent plant (the original plant which the cutting was taken from). In other words, it is a clone of the parent plant.
Taking cuttings is a reliable method to clone plants, but what happens when you need to clone more than a few plants? For example, one hundred. Cuttings wouldn’t be the best way to clone that many plants.
Tissue culture (otherwise known as micropropagation) allows you to clone many plants at the same time. This process involves:
1. Obtaining very small pieces of plants called explants.
2. Then, growing the explants in vitro (outside a living organism) using sterile agar jelly.
3. The cells grow into small masses of plant tissue (callus tissue).
4. This tissue will grow, forming plantlets, which can be transferred to potting trays, where they will develop into plants.
Tissue culture allows you to clone a large number of plants at the same time. However, it is more expensive than cuttings and the agar jelly needs to be sterile, otherwise microorganisms can interfere with the growth of plants.