| MadSci Network: Botany |
The word hybrid is used in various ways in biology. Hybrid tomatoes have two genetically different parents that are crossed each year to produce the hybrid tomato seed. Each parent is highly homozygous, e.g. for one gene, one parent may be AA and the other aa. This makes the hybrid seed highly heterozygous, e.g. Aa. Hybrids are usually more vigorous or have some superior traits compared to either parent. This is termed hybrid vigor. Tomatoes are normally self-fertilizing so are naturally homozygous. A nonhybrid tomato would be allowed to self-fertilize to produce non-hybrid seed. Growers can save seed of non-hybrid tomatoes to plant the next season's crop. Non-hybrid tomatoes come true from seed. Old non-hybrid cultivars (cultivated varieties) are often known as heirloom varieties. Creating hybrids is an advantage to the seed producer because growers cannot save their own seed for next season. They have to buy new seed each year to get the same characteristics in the hybrid. References Hybrid definitions Hybrid Tomato Seed Production Hybrid Seed Production in Tomato Save your favorite non-hybrid tomato seeds for next year
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