Over on Reddit, and with remarkable regularity, people have been asking what those weird markings on watermelons are, which are sometimes described as looking like “crop circles”.
A few days ago, one curious Internet user asked the same question, though a quick search finds that the question has been asked many times throughout the site’s history.
“I’ve worked for a grocery chain as a fruit cutter for the past 2 years. I’ve never seen this before,” Reddit user thelostsummoner wrote on Saturday.
“We got this watermelon shipment in this morning and on three or four of the watermelon, this pattern is like etched into the surface of the watermelon rind. It’s not on top! I picked at it with my paring knife and ran my hand over the pattern to make sure! I was wondering if anyone knew how this pattern got onto my watermelon! Was it from the farm or during shipment somehow?”
The patterns, which several users noted looked like “crop circles“, have a perfectly natural explanation, and are not the result of shipment (for example, laying on a box with that pattern embedded in it). Neither are the watermelons themselves dangerous because of the markings.
As suggested by several Reddit users, the markings could be the result of something known as “watermelon mosaic virus”. But it is a little more complicated than that, with several viruses affecting cucurbits like squashes, watermelons, cucumbers, and other gourds.
“It is difficult to identify a virus by symptoms alone,” the University of Minnesota explains. “Symptoms vary depending on the crop, variety, age of the plant at the time of infection, and in some cases weather. It is common to find plants infected with more than one virus at the same time, often resulting in combined severe symptoms.”
There are a number of viruses that cause these patterns, including Cucumber Mosaic Virus, Squash Mosaic Virus, Zucchini Yellow Mosaic Virus, and two Watermelon Mosaic Viruses (WMV 1 and 2).
“The virus’s effect on fruit depends on when it infected the plant. Early infections often result in no or very low fruit production,” the University of Minnesota continues.
“Later infection can result in fruit that is small, deformed and discolored. Fruit may have a mottled or mosaic pattern, ring spots or off-coloration on all or part of the fruit. Melons infected with squash mosaic virus (SqMV) often lack netting at maturity.”
The virus is largely spread through aphids and other insects, though spread through contact with tools and humans working in the fields may also be a factor. As for why this results in strange mosaic patterns, this is likely due to the interaction between the viruses and plants, interfering with ordinary cell processes.
“Plant viruses disrupt various cellular functions by interacting with host proteins, including dysfunction of chloroplast proteins, hormone manipulation, accumulation of reactive oxygen species (ROS), and cell cycle control, which contribute to the development of different types of symptoms,” a paper on the topic explains.
“ROS exhibits dual functionality in the invasion of pathogens in plant cells. Low levels of ROS have been demonstrated to promote signal transduction and acclimation/defense responses, whereas high levels of ROS lead to oxidation damage to lipids, DNA, and proteins. This oxidative damage can disrupt cellular functions and impair cellular components, ultimately resulting in cellular death and the emergence of necrosis or mosaic symptoms observed during viral infections.”
While the fruit may look odd, it remains perfectly safe to eat, despite the alien appearance.
“You can eat squash and melons that are infected with mosaic virus. These viruses are not harmful to humans and do not cause the fruit to rot,” the University of Minnesota explained in a blog post, per Snopes. “Often the discoloration is only skin deep. In cases where fruit is severely distorted, the texture of the fruit may be affected and may not be desirable for eating.”
All “explainer” articles are confirmed by fact checkers to be correct at time of publishing. Text, images, and links may be edited, removed, or added to at a later date to keep information current.
Source Link: People Are Confused By The Natural Markings On Watermelons That Look Like "Crop Circles"
