The apple tree may be the oldest cultivated fruit tree -- there is evidence of people eating them all the way back in the Stone Age. Today, the sweet taste and crunchy texture of apples continue to attract consumers around the world. In the United States alone, over 10 billion pounds of apples were sold in 2009, and demand keeps rising.
Now, a team of international scientists have sequenced the apple's genome. With the achievement, researchers hope to breed more luscious, mouth-watering apple varieties that ripen in different climates and resist disease.
"We chose to sequence the delicious apple because it is one of the oldest apple varieties in the world and also in the United States -- it took hold in West Virginia in 1890," Amit Dhingra, a researcher at Washington State University, explained to Discovery News.
Each apple has 34 chromosomes: a maternal set of 17 and a paternal set of 17. Sequencing all 34 chromosomes would generate loads of data, most of which would be redundant. Dhingra and his team sequenced half, which reduces the processing and analyzing time while still providing most of the juicy genetic details.
So far, Dhingra has discovered that the modern domesticated apple originated from a wild variety called Malus sieversii in southern Kazakhstan. Now the team is set on unlocking the apple's more scrumptious secrets, such as what genes control flavor.
Sifting through all the genetic information takes time. To speed up the process, scientists turned to some of the apple's relatives: pears, peaches, and grapes.
Even though these fruits look and taste different, they all share many of the same internal characteristics and genes. "Knowing how a gene in a peach works sheds light on how a similar gene may work in an apple," Dhingra said. "It also helps us identify what genes are unique to each fruit and how those genes may provide the fruits with a competitive advantage."
Many fruits require specific amounts of exposure to cool temperatures to fruit properly. Peaches need significantly less time in chilly weather than apples, for example. Comparing the two helps scientists identify the trait that controls chilling time in each fruit. Some day, fruit breeders might even be able to insert the non-chilling peach gene into apples.
"Sequencing the apple will greatly improve the way we breed apples," Dhingra said. Some day, growers might be able to produce apples that are naturally sweeter, tolerant to certain diseases, or that grow in warmer temperatures.
Image: Anthony Thomas, Flickr
Tags: Conservation, Engineering, Genetic Science, Trees
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