Seedless Cherimoya






This item is important because wemay just have a genetic protocol for producing seedless plants on demand. Itmay not be ready yet for prime time, but the possibility is now with us.

We forget that the seedlesscultivars we do have were never anyone’s first choice in terms of flavor andmany other characteristics.  Suddenly wecan plan to optimize a variety and then proceed to produce a seedlessversion. 

How about a better banana?

If this methodology can beadapted to the rest of our universe of cultivars, we are about to witness arevolution in flavor and quality.

My first nominee is to produce aproper sweet seedless watermelon.  From thatwe can also produce dried watermelon without fuss.  Both would have tremendous commercial value.

Just how many varieties of grapesare there?  I would love to eat astrongly flavored concord grape without the seeds while retaining the interiorstructure.


Seedless cherimoya, the next banana?



Mark Twain called it "the most delicious fruit known to man."But the cherimoya, or custard apple, and its close relations the sugar appleand soursop, also have lots of big, awkward seeds. Now new research by plantscientists in the United Statesand Spaincould show how to make this and other fruits seedless.

Going seedless could be a big step for the fruit, said Charles Gasser,professor of plant biology atUC Davis.

"This could be the next banana -- it would make it a lot morepopular," Gasser said. Bananas in their natural state have up to a hundredseeds; all commercial varieties, of course, are seedless. A paper describingthe work is published March 14 in the journal Proceedingsof the National Academy of Sciences.

Researchers José Hormaza, Maria Herrero and graduate student Jorge Loraat the Consejo Superior de Investigaciones Cientificas in Malaga and Zaragoza,Spain, studied the seedless variety of sugar apple. When they looked closely atthe fruit, they noticed that the ovules, which would normally form seeds,lacked an outer coat.

They looked similar to the ovules of a mutant of the lab plantArabidopsis discovered by Gasser's lab at UC Davis in the late 1990s. InArabidopsis, the defective plants do not make seeds or fruit. But the mutantsugar apple produces full-sized fruit with white, soft flesh without the large,hard seeds.

The Spanish team contacted Gasser, and Lora came from Malaga to work on the project in Gasser'slab. He discovered that the same gene was responsible for uncoated ovules inboth the Arabidopsis and sugar apple mutants.

"This is the first characterization of a gene for seedlessnessin any crop plant," Gasser said.

Seedless varieties of commercial fruit crops are usually achieved byselective breeding and then propagated vegetatively, for example throughcuttings.

Discovery of this new gene could open the way to produce seedlessvarieties in sugar apple, cherimoya and perhaps other fruit crops.

The discovery also sheds light on the evolution of flowering plants,Gasser said. Cherimoya and sugar apple belong to the magnolid family of plants,which branched off from the other flowering plants quite early in theirevolution.

"It's a link all the way back to the beginning of theangiosperms," Gasser said.

Provided by University of California - Davis