Hello fellow readers,
Summer picnics bring back memories of seed spitting contests. Hard to do nowadays as most watermelons are touted as seedless; though in truth it’s not so. Those little white thingies among the watery pink fruit are actually infertile seeds. True, they’re digestible. But so are the traditional black seeds if you’re so inclined. And both won’t cause a watermelon to grow inside your tummy. I still giggle over Mom’s warning which backfired and inspired me to eat more seeds.
‘Are seedless watermelon a GMO (genetically modified)?’ asked Lois from Tranquility, NJ. The consensus is they aren’t.
Designing seedless fruit has been in fashion for a very long time. In fact, seedless grapes have been rooted from adult grape plant cuttings for over 2,000 years. Making seedless watermelon, which began in the 90’s, is a totally different process. Much like horses mated with donkeys to make mules, seedless watermelons are considered hybrids – a mix of two species or varieties of plants or animals. Two mules cannot make more mules as they are sterile. Same is true of seedless watermelons.
The traditional watermelon has two sets of chromosomes. A chemical called cholchicine, derived from the autumn crocus plant, is used on seeds which causes the plant to grow four chromosome flowers. Pollinating a four chromosome flower with a two chromosome flower results in an infertile watermelon with three chromosomes.
It sure sounds fishy; that changing the number of chromosomes isn’t considered genetically altering. But a GMO uses genetic engineering to change DNA. While a chemical derived from a plant is used to create a chromosomal change in the original seed, genes from other organism aren’t used to modify a watermelon’s DNA.
So, how do you grow seedless watermelon if they have don’t have seeds that you can plant? It sounds like an oxymoron. (I just love that word which means self-contradictory.) You need to plant both four-chromosome seeds and two-chromosome seeds next to each other so when they flower they can cross-pollinate and produce watermelons with three chromosomes making them seedless.
It’s complicated to explain and I’m hardly an expert. I just want to spit watermelon seeds thank you very much. But I’ve outgrown the curiosity of what happens when you eat the seeds. Maturity sometimes changes the magic. Bittersweet (yes indeedy, an oxymoron).
Garden Dilemmas? firstname.lastname@example.org