Breeding plants to create new varieties and improve upon old ones is a hobby that nearly everyone can engage in. The crossing techniques are easy to learn and breeders can experiment with many kinds of plants. Generally, amateur plant breeders work with traits that are fairly easy to change-for example, flower color, fruit shape, or plant size. Nevertheless, although experiments may be simple, it is possible to produce unusual or beautiful plants. In order to breed plants successfully it is important to understand the principles of plant reproduction. The purpose of this is to explain the simple techniques that can be used to produce new varieties or strains of plants.
The first step in the plant hybridization procedure is the selection of parent plants with the desired characteristics. Plant characteristics can be changed after many generations by a process of selection. There are two types of selection-natural and artificial. Natural selection is the process that occurs in nature whereby strong and well-adapted plants survive while weak and poorly adapted plants eventually die out. This process has taken place since the beginning of life on earth and it is still occurring in nature. Artificial selection is the process that humans use to obtain more desirable types of plants. Thousands of years ago people learned that saving seed from the kind of plant they wanted to continue growing would increase the chances of getting a plant similar to the original. But our ancestors didn't know what their chances of success were nor did they understand the processes by which traits were changed or maintained. It wasn't until the eighteenth and nineteenth centuries that humans began to understand the laws of heredity and the processes of plant reproduction. Even today, these fundamentals aren't completely understood. But enough is known so that we can select plants for breeding with considerably more assurance of success than our ancestors did.
In our experiment we have to select the parents for the process of hybridization. The plants selected for breeding should be sturdy and healthy. It is usually easier to tell which ones are healthy after a few flowers on the plant have bloomed. Some plants have natural barriers to cross- or self-pollination. It is advisable to check for this before breeding, for although barriers can be overcome, some plants cannot be artificially pollinated. An example of a barrier that cannot be overcome is the selfpollination prohibitor of some orchids; the stigmas of certain orchids produce a substance, which kills the pollen of flowers of the same plant. The mechanism that performs this cannot be removed without destroying the pistil. In choosing a pollen parent (male parent), select one that has a heavy yellow powder on the anther. This powder is the pollen. In choosing a seed parent, examine the stigma. It should have either a glistening substance on it that is sticky to the touch or a "hairy" surface. It is this substance or surface that retains the pollen, thus making fertilization possible. Once the seed parents and pollen have been selected, you are ready to begin pollination.
Tags: Bio Technology, Bio Genetics, Breeding Methods in Plants
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