Climate change can make red apples disappear!

People have loved red apples for generations, but rising temperatures could be a sign of the end of a good dose for the body - red apples.

There may be yellow apples or green apples in fruit shops. In some places, you can even find striped or dappled varieties with a vibrant color, like the gorgeous Cox Orange Orange Pippin.

As temperatures rise, the chemical changes in apples make them less likely to be red.

But red or sometimes, the pure, sharp Granny Smith is the color of apples in most alphabet books. It has an interesting detail, because apples are not always so monochrome.

The ancestors of modern apples are wild plants that grow in what is now Kazakhstan, on the western flank of the mountains bordering western China. Today, wild apple trees still grow there, fragrant the air with fallen fruit, and provide bears to weave through the forest, although the number of wild apples has dropped by 90% in the last 50 years thanks to the Human development and their future are not so sure.

Fruits range in color from light yellow to cherry red and spring green, but red often does not stand out more than other colors. (An apple-loving traveler, Beck Lowe, reports that ironically, a commercial Kazakh garden, like orchards all over the world, is growing Red Delicious and Golden Delicious, apples derived from America).

Scientists have found that the apple's color arises from the level of expression of certain genes on its skin . David Chagne, a geneticist at Food and Food Research in New Zealand, explained that enzyme sets work together to turn several molecules into pigments called anthocyanins , the same substance that makes sweet potatoes. Purple, grapes and plums are colored.

The levels of these enzymes are controlled by a transcription factor - a protein that regulates the level of gene expression - called MYB10 , so the more MYB10, the redder the skin is. In fact, one study found that in apples with red stripes, the MYB10 concentration was higher in the striped parts of the skin.

Amazingly, the color also depends on the temperature. To get an apple that is completely red, the temperature must be cool, Chagne said, because if it is above 40C (104F), MYB10 and anthocyanin will be destroyed. In the Pyrenees region of Spain, he and his colleagues found normal vivid red striped apples completely pale after an exceptionally hot July. As the temperature warms, apples may become more difficult to turn red.

However, he and his colleagues are looking to create red fruits for the Asian market using their understanding of the biology behind colors.

Perhaps the threat that climate change poses to red apples will be absolutely determined by our breeding of them , even if it takes expensive breeding programs. Even before we understood genetics, colorful apples created a strong attraction to humans. John Bunker, an apple collector based in Palermo, Maine, has rescued many forgotten varieties from extinction. These include apples that were planted a century or more before the planting became very concentrated, including the magnificent Black Oxford, an apple so deep red that you might mistake it for. a large plum before seeing its bright white flesh. "Color is phenomenal, and I think for some people including myself, that's the original attraction ," he said.

Color may not have been the criteria for an apple when growers were evaluating a new tree. Instead, they focus on flavors and uses for apples: some are good for cider, some for pies, some for sauces and some for eating. It doesn't matter exactly what the fruit looks like and looks the same from tree to tree, because farmers are planting fruit for themselves and for their local market, and the function is more important than it looks. appearance.

Bunker said that all changed about 100 years ago. In a culture of small diverse farms and diverse small farm economies, uniformity is of limited value, he said. But if apples are grown from thousands of miles around to be bought in interchangeable form, the color becomes a kind of brand. In this commodity system, uniformity is becoming increasingly valuable. At the same time, apples begin to be picked before they are truly ripe so they can be transported long distances without decay.

There is a problem, color is an indicator of ripeness. Apples picked early do not have the right color. But then, an apple with the mutation gives it a reddish tone when it's ripe, he explained. That apple was eventually dubbed Red Delicious, and in 1921 was introduced to gardeners.

Other apples are found to be uniform in color, especially if they appear before the apple has actually reached full ripeness, which is great for business.

The number of farmers cultivating seeds began to shrink. And little by little, some of these varieties are not delicious, because the emphasis on shape is not conducive to taste. David Bedford, an apple breeder at the University of Minnesota, said that he grew up eating red apples and therefore didn't like apples very much: he tried a different kind at the university to wake him up for the possibility. Apple may be different from the original.

He and his colleagues stood behind the hugely successful Honeycrisp apple, known a few years ago for its juicy crunch. And in fact, Honeycrisp has a yellow and red striped beauty.

Ever since people made choices, they've made them redder and more - Dave Bedford. But even among apples that were bred to escape the curse of Red Delicious, red apples are still popular. People have now introduced Honeycrisps with mutations that make them even redder. This is what happens with every apple on the market, Bedford said.

Reder apples may not be better than yellow apples - in fact, they can be worse. In an attempt to remedy this, the University of Minnesota has launched other apples. In this system, growers are not allowed to pick reder fruits.

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