JoAnne Skelly: I’m a cloner and didn’t know it
At The Greenhouse Project (TGP), I saw a note on the board, “Plant Clones.” I asked Cory, the TGP manager, about that. He wanted to plant cuttings of a particularly tasty tomato he and the AmeriCorps interns had rooted in water, trying to reproduce it asexually. I never thought when I rooted cuttings in water that I was cloning the parent plant. I simply thought of it as asexual propagation. However, asexual propagation is one way of producing clones. Clone is actually from the Greek word “klon,” meaning “slip” or “twig.”
In asexual reproduction, the new plant is produced from a single parent and only has genetic material from that one parent. In sexual reproduction, the new individual has two parents and usually derives half its genes from one parent and half from the other.
Wholesale nurseries often do all their propagation asexually, planting hundreds to thousands of cuttings every day, reproducing their successes over and over.
In nature, many plants reproduce by developing young plants off a parent plant, like the hens and chicks succulent, a yucca or a spider plant.
It would be a huge agricultural breakthrough to be able to clone food crops via genetically identical seeds, because high-producing vigorous hybrids could then be reproduced indefinitely. Currently, asexual seed formation is not found in major food crops. If it were, farmers could propagate their own plants without buying seed every year, something that would greatly help subsistence farmers in developing countries.
With genetically identical seeds, seed companies could bring new plant breeds to market more quickly, possibly decreasing food shortages. Currently, our most productive food crops are hybrids of “two genetically disparate cultivars. But the beneficial combination of genes that makes the hybrids so robust disappears in the next generation because the genes are shuffled into new combinations during sexual reproduction” (https://www.nature.com/news/2011/110217/full/news.2011.102.html).
The word “clone” can evoke negative reactions. Yet, almost all fruit is cloned, because it is rarely grown from seed. Planting apple seeds won’t give you the same apple as the original. Most of our fruit crops are propagated from grafting or budding one kind of plant with tasty fruit onto the root stock of a plant that’s hardy, in the case of apples, often a crab apple. Nectarines naturally mutated themselves off a peach which lacked fuzz.
Nature often clones, not only in plants, but in microorganisms, insects, worms and some amphibians.
You too might have cloned plants and not even realized it.
JoAnne Skelly is Associate Professor & Extension Educator, Emerita at University of Nevada Cooperative Extension. She can be reached at firstname.lastname@example.org.