Peaches: The Role of Artificial Selection

Interview by Matt Johnson, Lecturer, Biological Sciences Department with
Dr. Desmond R. Layne, Peach Specialist, Clemson University

Matt: I joined Dr. Desmond Layne, South Carolina's state fruit specialist to discuss one of our tastiest fruits.  You know, we hear about Georgia to our west being considered "The Peach State" but I'll tell you, this is the main thing I've seen all my life here in South Carolina.  I have a tough time not counting South Carolina as the peach state!  

Des: We do consider South Carolina the peach state, in fact, South Carolina is actually "The Tastier Peach State".  

Matt: Laughing... I hear you!  How economically important are they in South Carolina?

Des: Well, it's about a $50 million dollar industry and it employs over a thousand people.  So, we are actually the #2 peach producer in the United States.  There are many large, family farms in the state.  It is a very important industry.  It is the most important fruit crop. 

Matt:  In our state?

Des: Yes, it is.

Matt: Where do peaches come from?

Des:  Well, originally, they came from China.  

Matt: Oh, so they're not from the United States?

Des:  No. They are not from the United States.  They were introduced here in the late 1500's by the Spaniards.  In fact, it wasn't until about the 1850's that they were being grown on a large commercial scale.  

Matt:  So they're originally from China - are they something that is an old species or is it something that is relatively new?

Des:  Well, actually, they have been cultivating peaches in China for about 4,000 years.  So, they have been selecting peaches throughout the centuries that will perform well under their climate.  What we are doing here is something very similar.  We've got about 350 different varieties that we are testing to see how well they will do in South Carolina so that our growers can be successful and make a good profit.  

Matt:  You've got a couple picked for us that we can look at?

Des:  I do.  We've got several boxes of peaches that come ripe at this time of the year.  Let's come and check them out.  You know, people have been selecting peaches for thousands of years and what we've got here is an example of some that are grown here in South Carolina or we're at least testing here at the Musser Fruit Farm that are quite different.  

Matt: How are these peaches different from peaches that you would see in the wild?

Des:  Well, in the wild, typically, peaches are going to be small.  They're going to have green skin.  There is going to be maybe a half-inch of flesh around the stone.  They are not going to be big and fleshy like these are.

Matt: So, they are not going to look like that at all?

Des: No, they're not going to look like this at all.   And you can see here that you've got nice, juicy, yellow flesh with a little bit of red pigmentation in there.    

Matt: So all the things that we see here are a product of manmade selection?

Des: That is correct.

Matt: You wouldn't have these here if we hadn't brought them in and artificially modified them in order to make them so that they are so tasty?!

Des: That's exactly right.  When we get from these white-fleshed peaches over here, this is a nectarine which is basically a fuzzless peach.  These ones are a little bit small but it does not have fuzz and that is a genetic trait.      

Matt: So, a nectarine and a peach are essentially the same thing?

Des: Yes, they are the same genetically except for change in the fact that they don't have fuzz.  We've got something weird at the end over there.

Matt: What in the world is this?  This doesn't even look like a peach!

Des: Laughing...  It looks like somebody stepped on it.

Matt: It does!

Des:  It's a donut peach - the common name.  But it's called a peen (or pan) tao.  It's from China and peen (or pan) means flat and tao means peach - so it's a peen (or pan) tao.  

Matt:  So, all these different peach cultivars ...  I guess one of the things that is important is that all of these have been selected for the qualities that they have.

Des:  That's exactly right.  So, somebody would have been a breeder and they would have been looking for traits that would be desirable for a consumer.  So good size, good color, good flavor, that the tree would produce a lot of fruit year after year, consistently.  Those are the main types of things that peach breeders would be looking for.  Do you want to see what these guys look like on the inside? 

Matt:  Yeah, let's take a look!

Des:  Alright, this is a typical California peach.  It's called Crimson Lady.  It's got the real strong red skin and nice, yellow flesh.  And this one here - this is Sugar May.  It's a white-fleshed peach and it's different. You can see on the inside as we get it cut open here.  Look at that!  This is yellow and this is white.  And it actually has some pigmentation in the flesh.  This red - these are anthocyanin pigments  - they are actually the same pigments that are in the skin and they are very healthy for you.  They have got a lot of good antioxidant capacity.

Matt: So you a lot of variation - not only in terms of peach size and shape but also in terms of the color and the texture and even the taste.  

Des:  That's exactly right.  

Matt: So these peaches, they wouldn't survive in the wild would they?  

Des: Probably not.  In fact, where we see orchards even in South Carolina that have been abandoned for one reason or another, the trees live maybe 15 years and then they die.  

Matt:  So what percentage of peaches in the United States are a product of artificial selection?

Des:  All of them.

Matt:  All of them?  So just as we're dependent on peaches for our economy, I guess they're dependent on us now in order for themselves to survive.   

Des:  We have to take care of them.  That's exactly right.

Matt:  It's just amazing to see that artificial selection has led to something as bizarre as this very oddly shaped peach!  Well, Dr. Layne, I appreciate you joining me today.  You must have a tough time working with these tasty peaches.

Des:  Well, I make lots of friends in the summertime and I'm glad to make a new one today!

Matt:  Me too, me too!  I appreciate it.