Sustainability Plus

Communications > Sustainability Plus > Posts > Cracked Genome Will Yield Tastier, Hardier Golden Delicious Apple

What's better than a golden delicious apple? A golden delicious apple that bares all to plant breeders.

Scientists have moved ever closer to such an apple. In what could be described as the ultimate day's work, an international team of sciences representing 20 institutions from the United States, three western European countries, and New Zealand have cracked the golden delicious apple's genetic code.

They recently published a draft sequence of the popular apple's genome in the current issue of Nature Genetics.

Up to now, the best apple breeders could do was to correlate traits with genes. Now, thanks to this drastically enhanced composite picture, they can attribute traits to specific genes.

In the long run, this could mean a considerably tastier and hardier apple for consumers, says Doug Chapman, a regional commercial horticulture agent with the Alabama Cooperative Extension System.

One of the original downsides of the golden delicious apple is that it russets easily, says Chapman.

In everyday language, that means that that the apples are predisposed brownish, roughened blemishes.

Using this newly mapped out genome, breeders may soon be able to breed this characteristic out of golden delicious apples.

Likewise, they may use this new insight to develop a longer-lasting golden delicious commercial variety that retains much of the fresh taste that so many consumers value.

"You can't beat a tree-ripened golden delicious raised here in north Alabama, but the store-bought apples from Washington and Oregon that have been refrigerated for weeks leave much to be desired," Chapman says.

New selective breeding programs on the new genomic insights will change all of this, he says.

The new genomic map also may help breeders better equip the apple against common diseases and pests.

"One of my old professors once said that apples are a lot like rabbits — everything out there is after it," Chapman recalls.

For Alabama apples, summer diseases such as black and white rot and bitter pit tend to be the biggest challenges for growers. Coddling moth, literally the "worm in the apple," is also as much a problem in Alabama as it is elsewhere.

As with other factors, such as taste, breeders will be better equipped to select for genes that provide the strongest safeguards against these threats, he says.

The next step beyond selective breeding is genetically modified apples — a prospect that brings jitters to some consumers and watchdog groups, although it shouldn't, Chapman says.

Through selecting for desirable traits, breeders of apples and other domesticated species have been involved in genetic modification for thousands of years, he says, adding that the only difference now is that the process will occur more rapidly.

As it turns out, newly acquired genome also has resolved an age-old — not to mention, hotly debated — question: the origin of the domesticated apple.

The genomicists have concluded that the wild ancestor to the modern apple is Malus sieverssi, native to the mountains of southern Kazakhstan.