What Is a Hybrid?

I mentioned in a previous post about buying hybrid seeds and I want to add to that topic.  Keep in mind when if buy hybrid  seeds, Some hybrid plants are developed for specific growing conditions, so pick ones that are right for your indoor growing conditions

Plants are usually classified as open pollinated or hybrid. An open-pollinated plant is the natural offspring of out crossing plants. Heirlooms are open-pollinated plants that have been essentially unchanged for many years. What I mean is that today's heirloom tomato plant is nearly the same as a tomato from a century ago. In general, the seeds from an open-pollinated plant will produce a similar plant the next grow cycle/season. A hybrid is a combination of two different varieties of the same species. Plant breeders usually develop hybrids for specific reasons, meaning they choose specific traits from the parents and try to combine them in the hybrid offspring. Some examples would be breeding/combining plants to produce more colorful or bigger blossoms, or fruit and vegetable plants tha are more uniform in size or more disease tolerant. Since the plants are genetic combinations from two different plants, their offspring (the F2) tend to have a lot of diversity and are not always the same as the hybrid parents.

Brief Hybrid History
From what I can tell, corn was the earliest hybrid developed for commercial use in America. The use of hybrids has extended to vegetables and flowers; and more recently, rice and some other crops. Scientists conducted experiments for many years on hybridization and saw that it often resulted in superior plants.  In the 1930’s less than 1 percent of corn seed was hybrid compared to nearly 100 percent today. There must be a a benefit to growing hybrids if they are increasing in such over whelming numbers.

What Are Hybrid Seeds?
Hybrid seeds are produced by creating inbred lines with specific reliable traits and then two established inbred lines are crossed to produce first generations (F1) hybrid seeds. The hybrid seeds are prized because they produce uniform plants and also have what is termed heterosis (hybrid vigor). Heterosis can result in a large increase in yield compared to the inbred lines or lines that are out-crossing (heirlooms). What exactly causes heterosis is still unclear. Thus, hybrid seeds are produced by companies through careful pollination of two specific varieties. Normally, this highly selective plant breeding is done to bring together two traits in each of the chosen varieties so that the resulting seed has both of the traits. For example, one tomato plant may be very drought tolerant and another tomato plant produces large yields, the two plants might be cross pollinated to produce a drought tolerant tomato plant that produces a lot of tomatoes.

The down side to hybrids, as I mentioned is that if you breed/cross plants grown from hybrid seeds they typically do not produce seeds that are all the same, and often can even produce seeds that are inferior to out crossing heirloom varieties.

Though the term “hybrid seeds” is often used in relation to vegetables, any kind of plant that produces seeds can be bred into a hybrid variety.

Good Growing,
Dr. E.R. Myers

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