SSS 2011-03-21

（单词翻译）

This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute.

Mark Twain called it "the most delicious fruit known to men." He was talking about the cherimoya. If you never heard of it, there's good reason. It has a feature that has prevented it from becoming widely popular—numerous big seeds fill its sweet white flesh.

But now scientists in Spain and at the University of California, Davis have found the key to making the cherimoya and related fruits seedless. They published their research in the Proceedings¹ of the National Academy of Sciences.

It's generally tough to develop a seedless fruit—bananas and oranges are rare successes. Breeding for seedlessness usually fails to produce the fully³ developed fruit consumers demand. But the scientists found a spontaneous mutation⁴ that causes seedlessness in a cherimoya relative, the sugar apple. They compared its genome to that of a seedless mutant of a plant called Arabidopsis that's used in a lot of research.

In both cases, they found a deletion of one particular gene². The researchers say this is the first time a gene for seedlessness has been determined⁵. If they can find a way to knock out that gene in the cherimoya, it could bring Mark Twain's favorite fruit, and many others, to a grocery store near you.

Thanks for the minute. For Scientific American's 60-Second Science, I'm Cynthia Graber.