The traditional ‘Sugar Baby’ watermelon is a seeded type and not a naturally seedless fruit. This melon belongs to the category of diploid watermelons, possessing the standard two sets of chromosomes necessary to produce mature, viable seeds. Hybrid watermelons are genetically structured to prevent the development of hard, fertile seeds. The Sugar Baby is an heirloom variety that maintains its original characteristics, including the presence of firm, dark seeds throughout the flesh.
Characteristics of the Sugar Baby Variety
The Sugar Baby is classified as an “icebox” or personal-sized watermelon, a designation given because its small dimensions allow it to fit easily inside a refrigerator. Typically, these melons are round and weigh between eight and twelve pounds, with a diameter of about seven to ten inches when fully ripe. Its exterior is distinguished by a smooth, dark green rind, sometimes showing faint mottling, which turns a duller color with a yellow ground spot when ready for harvest.
The flesh of the Sugar Baby is prized for its deep red color and fine texture, delivering a refreshingly sweet flavor due to its notably high sugar content. Scattered within this flesh are the mature, hard seeds that define it as a seeded variety. These seeds are typically small and black or brown, capable of being planted to produce a new watermelon vine. This variety is open-pollinated, meaning its seeds will reliably grow into the same type of plant year after year, a key trait of heirloom melons.
The Science Behind Seedless Watermelons
Seedless watermelons are the result of specific genetic manipulation in the breeding process, not a natural mutation. Standard seeded watermelons, like the Sugar Baby, are diploids because their cells contain two sets of chromosomes. To create a seedless fruit, breeders chemically treat a diploid plant with a compound like colchicine, which causes the chromosome number to double, resulting in a tetraploid plant with four sets of chromosomes.
The next step involves cross-pollinating a female flower from this tetraploid plant with pollen from a standard diploid plant. This genetic cross produces a seed that is a triploid, possessing three sets of chromosomes. Because the triploid has an uneven number of chromosomes, its reproductive cells cannot divide normally during meiosis.
This chromosomal imbalance renders the resulting triploid plant sterile, similar to a mule. When a triploid flower is pollinated by a standard diploid plant, it is stimulated to produce a fruit that is “seedless.” The triploid fruit will contain only small, soft, white seed coats, which are undeveloped embryos that remain edible.
Distinguishing Seeded and Seedless Types
The most straightforward way to distinguish a seeded variety like the traditional Sugar Baby from a seedless hybrid is by examining the internal structures. Seeded watermelons contain hard, dark seeds that are fully mature and capable of germination if planted. These seeds are firm to the bite and are generally spat out by consumers.
In contrast, seedless watermelons contain only soft, pale structures that are immature seed coats. These undeveloped seeds are non-viable, meaning they will not grow into a plant, and they are soft enough to be swallowed without being noticed. While some consumers may mistakenly believe these white, undeveloped structures are seeds, their pliability and sterility confirm the fruit’s seedless classification.