Plant hybridization is nothing new to science; as a species we have been breeding plants together for thousands of years.
Here we will discuss hybrid plants in the classical sense and how this hybridization has helped science.
In the mid-late nineteenth century, a monk by the name of Gregor Mendel started experimenting with bean plants. He was determined to explore and understand how genetic traits were inherited from parents to offspring and so on. He started off with true breeding plants and bred them together to create a group of offspring. He then bred them again, keeping track of whatever trait he was looking for.In Mendel’s experiments, it was said that he used true breeding plants. This means that he used plants that only had specific genes that produced a specific trait.
The genotype is the genetic makeup of an organism, and its phenotype is the observed trait that is produced by the genotype. In Mendel’s case, he sought out pea plants that produced a certain phenotype from a specific genotype.Mendel tested one trait at a time, such as color. In pea plants, purple is thought to be dominant over white plants. Mendel found purple plants that had a genotype PP, giving a phenotype of purple flowers, and white plants that had a genotype ww, giving a phenotype of white flowers.When Mendel crossed this parental or P generation of plants, he crossed purple with white, or PP with ww, giving a first filial or offspring (F1) generation of plants with a phenotype of purple flowers but a genotype of Pw.
These would be called hybrid plants.Gregor Mendel tested many different aspects of plants, such as height, wrinkled vs. smooth, shape of the pods etc.
Hybrid plants are nothing more than plants that have been successfully cross-bred with other plants to take advantage of certain traits and get rid of other, less advantageous traits. Two true breeding plants are bred together in hybrid plants in order to get a certain trait from the two. In Gregor Mendel’s experiments, he would take true breeding plants for a certain trait and breed them together to get plants that gave one of the traits but had genes for both sets.
Hybridization occurs in most of the plants that are consumed today, such as vegetables and fruits. This is done through careful crossing of plants to get traits that we find useful, such as resistance to pests and disease, lack of water, etc. This has been going on for many, many years. It allows growers to get the best qualities out of their plants as well as produce a good yield of crops.
Advantages of Hybrid Plants
The biggest advantage that we see in hybrid plants is that scientists are cross-pollinating or cross breeding plants for their specific traits that growers and consumers want. Some plants are resistant to drought, others are resistant to pests, some yield better tasting crops, others yield cheaper food sources for livestock, etc.After so many crosses of plants, scientists have actually created newer varieties of plants that end up having the traits that many people look for. From an economic standpoint, this is great, providing better products for less money.
Disadvantages of Hybrid Plants
One of the main problems with hybrid plants is that a P generation is cross-bred to create an F1 generation. All of the plants in the F1 will have the same genotype as well as the same phenotype.
However, if the F1 generation is bred together or even self-bred, what occurs is an F2 generation (2nd filial or 2nd offspring) that is not 100% true for a certain trait.If we use Mendel’s pea plants as an example, you have a purple (PP) and a white (ww) for the P generation. Once crossed, there are purple plants with the genotype Pw.
However, when crossed, there will be 3 purple plants and 1 white plant. The white plant will be ww, the purple plants will be one that is PP and two that are Pw. So they won’t be the same as the F1 generation. This is an issue for farmers, as they are looking for the same as the F1 generation.
In order to get the F1 generation, the farmer has to go back to the start in the P generation.So a big disadvantage is that hybridization doesn’t always work the way the grower would like, and oftentimes they have to become reliant upon getting new seeds each year and starting the process over again. A farmer can’t just harvest your seeds and use them next year; her or she will need new seeds.
True breeding plants are those that have a pure genotype for a specific trait.
When bred, they will produce a specific phenotype. Hybrid plants are those that are the result of cross-pollinating two true breeding plants. Hybridized plants will have a specific phenotype, but have a genotype that reflects both of the parents – they are created to get certain specific traits out of the parents.
Hybrid plants allow farmers and horticulturists to breed plants for specific advantageous traits, like drought and pest resistance. The downside is that the first generation will produce the proper hybrid plants, but the second generation will not. Growers need to buy new seeds in order to start the process again.