Gardeners need all the information they can get about the plants they cultivate. Experts are clear about how seedless watermelons are produced, but some disagreement arises when considering how to categorize the genetic mules. Is a seedless watermelon a GMO, a hybrid, or something else altogether? There is some disagreement on this point. Ultimately, it’s a matter of how a GMO is defined, and consumers are at ground zero of this high-stakes word game.
Seedless Watermelon Production
To make seedless watermelons, the number of chromosomes in traditional melons are doubled by adding the chemical colchicine. This doubling leads to a plant with four sets of chromosomes, called a tetraploid plant. The tetraploid is then pollinated with the original diploid melon, and out comes a seedless watermelon seed! The process is explained by theTexas Agricultural Extension Service. Coincidentally, colchicine is a medication commonly used to treat gout. Side effects of the medicine may include vomiting, abdominal pain, cramping, and diaherra according to WebMD.
Are They GMOs?
Of course, GMO stands for genetically modified organism. Scientists may refer to the food products as genetically engineered (GE) organisms and group them within two categories: transgenic, and non-transgenic. The transgenic varieties are modified by taking a gene from one species and adding it to another, while the non-transgenic are produced by altering genes within one species. Hybrid plants are the result of artificial selection that involves cross-pollinating to breed desired plant characteristics. Where do seedless watermelons fall on this spectrum?
Prominent biotechnology researcher, Professor Nina Fedoroff, includes seedless watermelon in this discussion about GMO foods on the Penn State Science page. However, a Penn State Science course page refers to seedless watermelons as “a genetically created hybrid.” This seems reasonable until you consider how the tetraploid seed is created. Explanations of the fruit as a hybrid tend to leave out that colchicine is used to double the chromosomes.
The USDA Position on Seedless Watermelons
Genetic engineering is an excluded process under the USDA Organic labeling standards. To be tagged with the “USDA Organic” seal, a food product must be determined to consist of at least 95 percent organic ingredients. So, how can we get a “USDA Organic” tag on a watermelon produced with a seed that’s had the chromosomes doubled using colchicine?
The answer likely lies in the USDA’s loose definition of genetically modified. This definition states that, to be genetically modified, a living organism must have had a gene from an “unrelated species” inserted into it. In other words, the USDA definition of GMO includes only the transgenic variety of GE organisms. Thus, according to the USDA, rearrangements, subtractions, or additions made within the chromosomes of one living organism do not prevent that organism from being organic.
Seedless fruit varieties are often called “mules” because they can’t reproduce on their own. One big difference is that a donkey and a horse don’t need colchicine to produce a mule. The science used to make seedless watermelons has been with us for decades; this USDA technical bulletin from 1971 is evidence of that. You decide: GMO, hybrid, or something else altogether?