I was at a farmer’s market the other day and I overheard a customer say they once planted some green peppers (not hot) in a row adjacent to some hot chili peppers, and the green peppers became hot.
Is this possible? It would mean that capsaicinoids created in one plant were transferred to another kind of plant thru the roots, or maybe by air? Doesn’t seem likely.
If it is possible, are any other characteristics transferred the same way?
Pollination. Heat in peppers is a dominant trait, so you have to plant sweet varieties away from hot ones, or they will cross-pollinate and your sweet bells won’t be so sweet anymore.
Sure, but shouldn’t we expect that trait to be expressed in the offspring, rather than the fruit of the currently-pollinated generation.
So the resulting seeds would contain the hot characteristic, and if planted, would inherit it?
There must be a degree of separation in the family tree that would prevent this. How distant do the plants have to be (gene-wise, not geographic-wise) before they can’t cross-pollinate?
Hot chilli peppers and bell peppers are the same species.
But I’m dubious about genes from the pollen parent being expressed immediately in the seed that pollen produces
The heat is all in the seeds and associated pith. I think that would happen as a result of pollination (ie immediately) and would then be an inherited trait.
Calling a genetic biologist! I just checked my gardening books and they all say the same thing: don’t plant hots next to sweets if you want the sweets to stay that way. No mention of any generations involved.
Those structures are produced by the parent plant, not by the embryo. Or at least, that’s my understanding.
I suggest they are assuming that the gardener may routinely be saving open-pollinated seeds for next year.
So hot bananas, corn or maple syrup is out?
I’ve planted sweet banana peppers in very close proximity to jalapeños (as well as other, even hotter peppers) and I’ve never had the banana peppers become hot. Cross pollination might effect the offspring (I don’t save my seeds) but it does NOT effect the current peppers at all.
IMO the customer is either mistaken or planted cross pollinated seeds.
So we’re still left with the OP’s question: Does the heat transfer to neighbouring plants in the same generation? Zyada and I tried it this year with jalapenos in the same pot with tomatoes, but the peppers turned out to be that evil mutant flavourless strain. (I guess that’s what I deserve for buying the plants from the rack in front of a hardware store.)
If the heat does transfer, what is the mechanism - roots, air, rubbing against one another, …?
Edit: Of course someone posted while I was typing. I guess it doesn’t work after all, even with real jalapenos.
It seems more likely to be a pollination effect than roots.
OK, I looked this up.
In flowering plants, the pollen contains two sperm - one fertilises the ovum and this union gives rise to the embryo, which will grow into the seedling upon germination. The other sperm unites with other cells in the female flower and the product of this union is the endosperm, which serves as a food store for the embryo.
So the genes from the pollen are being expressed during the development of the embryo and endosperm, but this all takes place within the testa - the seed coat, which is entirely the tissue of the maternal plant.
So maybe it is concievable that pollen from a hot cultivar could induce hotness in the seeds of a mild cultivar - but it’s unclear to me whether the heat producing compounds could travel through the seed coat, or if the heat would only be discernible if the seeds were cut or crushed.
In any case, it looks like I might have been at least a little hasty in my previous posts in this thread, but I think we probably need the input of a qualified botanist at this point.
I think Mangetout outlines the situation concerning pollination correctly. However, although it would theoretically be possible for pollen from a hot variety to make the endosperm and embryo tissue hot, according to Wiki:
So apparently a capsaicin-producing gene in the pollen would not be expressed in the seed. The other tissues mentioned are all derived from the maternal plant, so they would also not contain capsaicin.
I don’t think that it would be possible for capsaicin to be transmitted through the soil adjacent plants, especially since it is mainly present in the fruit and not in the roots.
Unless there’s some sort of hormonal thing going on? - if perhaps capsaicin production is controlled by a hormone that is produced sparingly in the sweet varieites and abundantly in the hot ones? If that’s the case, that could concievably be transferrable via close contact.
I don’t believe that this is the case. In any case, green peppers have a recessive gene that blocks capsaicin production.
We don’t have any proof, just an anecdote overheard at a farmer’s market, that the green peppers were hotter than usual (and we have no controls). Maybe before we try to find out why, we should determine if the reported phenomena exists.
Are you sure that they meant that the green peppers became hot that season, and not that plants grown from the seed of those green peppers produced hot peppers the next year? Since the lack of capsaicin in green peppers is recessive, cross-pollination would result in next year’s plants producing hot peppers.
According to this site:
I would think if hotness could be transferred between plants directly, they would mention this.
I was overhearing a conversation, but I understood them to mean that planting two rows the same year resulted in one modifying the other the same year. It’s entirely possible I misunderstood, but that explains my puzzlement.