Tuesday, February 20, 2007

Seedless fruits

During the past few days we have been celebrating what is called 'Chinese New Year' in Malaysia and Singapore, 'Spring Festival' in China and 'Tet' in Vietnam. In Malaysia and Singapore, lots of mandarin oranges are consumed during this festival. This year I have been struck by the fact that most of the mandarin oranges are seedless. If mandarin oranges can be made seedless, we may expect other citrus fruits to follow.

Of other tropical fruits, we can expect mangosteens to become seedless. Already we have come across the odd seedless mangosteen fruit. Somebody should find a way to convert this rare possibility to certainty. With durians, nangkas, chempedaks and chikus there are trees that produce fewer seeds per fruit as well as fruits with reduced seed size, but we do not know if complete seedlessness is possible. Does anybody know?


Anonymous said...

why not just breed the seeds out like any other characteristic? Oh, I know... no seeds, no propagation! :-)

cloning... except consumers in the developed world have indicated a strong preference against cloned (tissue-cultured, cutting-grown, I dunno) products from dairy farm animals such as cloned cattle. Wonder why they have no such preference against cloned fruits?

Dr Francis Ng said...

There is a story that in English high society, they used to assess the social background of people by seeing what they did with cherries offered after dinner. Those from low society would spit out the seeds ('stones'). Those attempting to disguise their low origins would swallow the seeds. Those born to high society would discreetly transfer the seeds to a teaspoon and arrange them neatly on the sides of their plates.

In mainland China, they serve watermelons to guests on every occassion and it is OK to spit the seeds out into a spitoon (they may have to re-educate the public before the Olympic Games in Beijing), but polite society in Hong Kong and Taiwan, would rather pay extra for seedless watermelons.

Of course seedy bananas would never sell in any society.

The problem with the development of seedless fruits is that in nature, seed and fruit formation are tightly linked together. No seeds = no fruits. The trick is to delink them to get fruits without seeds, but this is not an easy trick to perform. If a way is found, then the seedless plants would have to be propagated by cloning, which is relatively easy for plants.

Potatoes, yams and other root crops, and most commercial fruits such as grapes and bananas are propagated by cloning, and has been for centuries, so there is no stigma attached to plant cloning.

The cloning of animals is something new, hence the risks are unknown.

ljmoi said...

I threw the seeds and peels of mandarin oranges on my plants as compost during the recent CNY and many have sprouted. Not sure whether they will survive- maybe they will, but perhaps they won't fruit?

Dr Francis Ng said...

I have given up growing oranges from seeds, because they produce big thorns and none have ever fruited in my garden. I am informed that citrus fruits produce big thorns during their juvenile period and the way to bypass this period is to propagate shoots from mature trees by marcotting. Mandarins are successful in various parts of Malaysia, so you may get lucky with your plans.