How do they grow more seedless fruit?

Illustration by Slug Signorino

Cecil replies:

Guess you can’t just plant more seeds, huh? But the fact is, you wouldn’t want to plant seeds even if you could. Sexual reproduction, which is mostly what you’re talking about when you grow things from seeds, is too chancy. I’ll say, you mutter. But if you think you’ve got problems, talk to a commercial fruit grower. An important function of sex, after all, is to shake up the gene pool. While that lends a certain charming variety to the offspring of us humans, it’s not something you want to encourage in, say, a Thompson seedless grape.

Luckily, sex is only one method of propagating a species. There’s also asexual reproduction. Aha, you’re thinking, so that’s how my parents did it. No, smartypants. Asexual reproduction means making copies of the parent plant by means of cuttings, grafting, and so on. The offspring plants have the advantage, from a horticultural standpoint, of being perfect genetic duplicates or clones of the parent plant. So once you’ve bred the ultimate rutabaga or what have you, you can crank out exact copies unto the hundredth generation. And people do just that. Some grape “cultivars,” as human-bred (and often human-dependent) varieties are called, date from Roman times — that is, the plants we have today are exact genetic copies of ones first grown 2,000 years ago.

What I’m telling you is that seedlessness is no big obstacle, plant reproductionwise. Most grape varieties, seedless or not, are reproduced by grafting. Ditto for citrus and fruit trees in general. (Actually I believe they “bud” fruit trees, but let’s not trouble ourselves with details.)

So, you think you understand? Time to obfuscate the situation. It’s possible to buy seeds that, when planted, produce seedless watermelons. Whence cometh this seed? It’s the product of an unnatural union between different varieties of watermelon, resulting in a hybrid that, like many hybrids, is sterile. You plant the hybrid seeds, and you get a plant whose fruit matures but whose seeds are underdeveloped. To make more seed you have to keep mating the mommy and daddy plants. There’s a lot more to it than that, but that’s about all I can explain without charging you quarterly tuition. Pass me a grape.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.