A sport, or random natural mutation, can change a plant's characteristics. It is a rare event, but one that led to most of the plant varieties we grow today, selected over thousands of years. Not all mutations are beneficial (in fact most are not and would be selected against) but a few can be. It is the accumulation of these changes, often combined through breeding, that make cultivated forms different from their wild ancestors (as, for example, corn is very different from teosinte). This is how we feed ourselves and the world.

Use of chemicals or radiation to increase the rate of mutation increases the frequency of finding useful new traits, and can lead to improvements in yield and other characteristics in decades rather than millennia. Once a change in the DNA has occurred, it is inherited by subsequent generations and no traces or the original mutagen remain. It is simply science speeding up the process of natural variation, arguably in a less than natural way (but naturally-occurring radioactivity is present and varies across the environment as well).

Modern approaches, like the CRISPR editing used in that paper, can be targeted to specific genes and again leave no trace after they have acted apart from a heritable change in the DNA sequence. CRISPR events cannot be distinguished from natural gene mutations, except that the process of targeted gene mutation is more efficient and can lead to crop improvements in the span of months to years.

And with gene editing you know what you've done. Irradiation is an unknown.

Back to the original post, I'm surprised that nobody has recognized what it is but it's something that you're going to see more of in the future, micro dwarf tomatoes. They are tomatoes which can be grown in one-gallon or smaller pots. I grew Pinocchio this past season and quite probably there were more fruit than leaves. Plants maxed out at less than 10" tall.

Martin

If you click on the image in the article it opens up to a larger version and this is at the bottom:

"When three specific genetic mutations are combined and tuned just right, scientists can turn tomato plants into extremely compact bushes ideal for urban agriculture. Just two of these mutations (insert, left) shortens the normally vine-like plants to grow in a field, but all three (insert, right) cause their fruits to bunch like grapes. Researchers cut away the plant's leaves for a clearer view of the new tomatoes. Credit: Lippman lab/CSHL, 2019"

So they cut away the leaves but don't say how many. I am all for research into making yields higher or crops more disease resistant but leave our taste, sweetness, and twang alone. If the tomato doesn't have some hardship during its life I find that it lacks either in flavor or texture or both. When we replace all of the farming with science we end up with the GMO tasteless round blobs that are currently sold in grocery stores!

Nan6b wrote: ↑Mon Dec 23, 2019 6:58 pm https://phys.org/news/2019-12-tomato-id ... outer.html