Sweet corn became sweet due to a genetic mutation (or mutations) in standard corn (Zea mays) that resulted in the kernels storing more sugar instead of converting it into starch, which is what happens in field corn.
Understanding the Mutation
The core difference lies in how the corn plant handles sugar.
- Field Corn: Field corn varieties efficiently convert sugar produced during photosynthesis into starch. Starch provides energy for the plant and contributes to the dry, starchy texture of the kernels.
- Sweet Corn: In sweet corn, a mutated gene disrupts this conversion process. This disruption means that more sugar remains in the kernels, giving them their characteristic sweetness. Different mutations can affect the sweetness levels and shelf-life of sweet corn varieties.
Historical Context
The earliest known varieties of sweet corn were discovered and cultivated in Pennsylvania during the mid-1700s. This indicates that the mutation that gives rise to sweetness occurred spontaneously and was then selected for and propagated by farmers.
Key Takeaways
- Genetic Mutation: Sweet corn arises from naturally occurring genetic mutations.
- Sugar Retention: The mutation prevents sugar from being efficiently converted to starch.
- Early Discovery: Sweet corn varieties were first identified and cultivated in the 18th century.
In summary, sweet corn isn't a different species from regular corn, but rather a variant that arose due to a genetic mutation which allowed it to retain more sugar in its kernels.
