That’s not correct in any possible sense.
In many cases, pollination is fundamentally essential or no fruit will form at all. There are exceptions.
I knew some guy that went the dump to get rid of some junk and same back with a marijuana plant.
And I found one in someone yard , someone threw a marijuana butt on the ground and a seed took root and grew.
We have some apples trees in my yard and the apples rot on the ground , if any seed did take root it would be cut down while cutting the grass.
My ackee tree likes to propagate. Every season some of the ackees drop and sprout. I’ve never seen a new tree grow, so I assume something is self-regulating them. Maybe the iguanas.
Well, pretty much any fruit tree is insect-pollinated. Wild bees will pollinate a lot of them, but beekeepers actually truck honeybees around too. This is a necessary expense.
A great deal of apple and fig cultivation, and IIRC almond cultivation as well, is planting cultivars next to each other that will pollinate each other. Less of an issue with cultivars that “self-pollinate” like, um, peaches?
But even “self-pollinating” trees actually rely on insects (or bats, or birds) to move the pollen around. I don’t know if any trees wind-pollinate.
Where are you that you can grow ackee? That’s fully tropical.
This article on inter-species grafting is re-investigating gene transfer theories that were previously rejected. Localize gene transfer at the point of the graft has been established, but that travel was believed to be limited to short distances. Research indicates this isn’t always the case. However, it doesn’t explain the concept that ‘offspring take after their rootstock’ since most indications are that genetic transfer doesn’t reach the fruit. That may be simply that the rootstock will be idealized for local conditions such as soil, temperature, and growing season that will affect characteristics of the fruit either from the rootstock or the graft.
We have an invasive weed type tree from NH and it propagate like crazy and it taking over the yard ! It’s growing on the lawn and the garden , I am constantly pulling the damn things out but they are everywhere and ugly too.
The sap burns your hands too.
Broward County, in South Florida. The tree is very happy here.
It came with the house - previous owners were Jamaican. I haven’t acquired the taste, but my Jamaican friends keep threatening to come over and harvest. I’d be fine with that.
A few years ago I was on a cruise that stopped in Jamaica. We passed some Ackee trees, and the guide asked if anyone knew what they were. I - clearly American - answered…much to her amusement.
Well, I was searching the internet to find any indication that the ‘offspring take after the rootstock’ and that was the closest I could find; as Naita points out, the mixed-up cells produced were propagated vegetatively from locations near the graft.
So far I can’t find any indication that the seeds of a grafted plant are affected by the rootstock genetically; do you have any cites for this? I’m interested to find out.
Perhaps there are epigenetic effects - a plant growing naturally without a suitable rootstock might be feeble and unable to produce healthy seeds, while one growing on a rootstock would have healthy seeds. Epigenetic effects could make the second generation very different in each case- the plants growing from the seeds of the plant without a rootstock would have a very poor start in life, and some aspects of gene expression might be different.
In grafted fruit trees, most of the characteristics of the individual fruits (flavour, colour, etc) come from the scion (the variety grafted on top) - the rootstock typically influences the size and growth habit of the tree, the total yield (and sometimes the size) of fruit and the number of years before the tree can be expected to start bearing.
In very simple terms - the rootstock is chosen as something that makes a good, healthy and suitable tree; the scion is chosen as something that produces desirable fruit.
There are such things as ‘graft hybrids’ (usually of two different species or genera) where the tissues of the two grafted parts mix throughout the plant and result in a weird mixture of physical attributes (I think in these cases though, there’s still not genetic mixing happening - just mixtures of the two different sets of cells from the two graft parents).
I thought I posted in the link. Now I have to find my way back to that article. Epigenetic effects are in the area I was thinking of, but it could also be simply environmental. The seeds don’t reproduce the rootstock, if they grow they’ll be the original scion grafted onto the rootstock, and grown by itself it could show different characteristics based on the local conditions. Any similarities between the offspring and the rootstock will be coincidental.
Citrus seeds are often polyembryonic - producing multiple seedlings per seed; some of these multiple seedlings may be clones of the parent (I’m not sure of the mechanism, perhaps it’s viable embryos arising from some process other than pollination).
But that’s still a clone of the scion in that case, not the stock.
One thing to consider WRT discarded fruit seeds and pits is that you probably eat the better part of the fruit that would otherwise nourish the seed as it rots, thereby depriving the seed of a bit of fertilizer and protection from drying-out. For a feral fruit-bearing plant to take hold, I imagine it would require near perfect conditions with soil and moisture, even if accompanied by the whole fruit.
I have seen a lot of wild mangoes - perhaps their large seed gives the tree a better chance of taking root than some other fruits. Blackberries are small, but there are so darn many seeds that the odds of one taking hold are pretty good, even in marginal areas, and they are distributed by a variety of animals.
Fertilizer may be a factor, but not from the fruit rotting. In the usual wild situation, fruit is generally eaten by an animal whole. The seed passes through the animal, so it gets fertilizer, but not from the rotting fruit. Note that wild fruits are generally much smaller than domesticated fruit. The plants make them just big enough to entice animals to eat them in multiple quantities. Anything bigger is a waste from the plant’s point of view, so is selected against.
That’s not to say that no fruit just falls to the ground and rots, but that doesn’t spread the seed very far.
One of the reasons fruit seeds may not sprout where you live is because you live in a climate without cold enough winters.
Many fruits that are native to temperate regions of the world (such as apple, pear, cherry, and so on) require a period of winter cold before the seeds can germinate.
You can usually simulate this process by soaking the seeds in water for 24 hours and then leaving them in the refrigerator for 2 months, wrapped in a moist paper towel sealed inside a plastic bag. If there is any out shell of the seed, it helps to (carefully)crack it before the initial soaking. After the chill in the refrigerator, the seed can be sprouted in warmer conditions.
Furthermore, the climate in some regions of the United States is not really the most conducive for fruit trees to grow by themselves in the wild. In Southern California, for example, fruit trees require a lot of watering during the hot dry summer. In Florida, the heat and humidity combined together make most fruit trees very prone to fungal diseases.
About the seeds of fruit trees not producing the same variety- the answer is SEX. The fruit has the genetics of the grafted parent, say Red Delicious apple. All Red Delicious apple trees are clones of the original one. Plant a seed from one of those apples, and you’ll get something different, since the seed has different DNA from the apple it was enclosed in, since the embryo in the seed came from a sperm cell (from pollen) and an egg cell (in the ovule).
This doesn’t mean the apple from a seedling tree will necessarily be bad. When I was a kid, the owner of a local orchard had a tree he let grow from seed, and the apples therefrom were excellent.
Usually fruit trees grown from seed are considered to be inferior, but you are right, this is not always the case.
I find a lot of feral apple trees when I am out walking, here in the south of England - in many cases, you can pretty much guess their parent variety based on the physical attributes of the feral fruit (as well as knowing that Gala, Braeburm, Granny Smith etc are popular and therefore likely candidates).
In nearly all cases though, the fruit is smaller and less sweet than the cultivated varieties (although I have found one or two exceptional feral apple trees that produce very good fruit).
I believe the success rate for raising worthwhile new apple varieties from seed is something like 1 in 10,000 or more.
The habit of grafting many fruit trees probably has an unintended consequence of removing any evolutionary pressure to maintain seeds that grow well. All the selection (un-natural selection - which is an oft missed point in contrast to natural selection) is selecting for good fruit or disease resistance (or both). There is no component of the selection function that includes an ability for the seeds to grow well. Even the root stock is typically struck from mature trees, so both ends of the new plant are clones.
New varieties may be nurtured under ideal conditions, and so the ability of seed germination and early maturation to survive the rigours of the real world are of greatly lessened importance.