How exactly does cross-breeding work?

[tru]

I feel like this is such an amateur question but we all gotta start somewhere;

When you cross, does the fruit come out looking/tasting/tell you anything about the crossed variety? Or does look like a normal fruit and just the seeds are altered? Or is it case by case where different species react differently to crossing

Thanks so much, would appreciate anyone sharing their introduction to breeding/how they got started

[K-Rimes]

Well, when a mommy plant and a daddy plant love each other very much....

But in reality, it's about isolating the "male" and "female" with the genetic traits you wish to pass on. In most cases, plants produce both female and male pollen and you just presto-exchango them and you've got a hybrid. The fruit itself will not look any different than the usual parent fruit, but the seed will produce a hybrid of the characteristics that the "father" and "mother" possess.

Some species are able to be crossed quite nicely - stonefruit comes to mind. Others it's a lot more experimental. Dr Richard Campbell has been working on introducing wild mango genetics into selected Florida mangoes for disease tolerance, he's dubbed them "Wangoes" and I was lucky enough to try one. While it wasn't a stand out in size or taste, it was unique at least in flavor.

There are probably much more experienced growers here who can go into more detail about crosses and what happens on either end of the Male or Female plant and the fruit / hybrid produced.

[drymifolia]

The fruit itself will not look any different than the usual parent fruit, but the seed will produce a hybrid of the characteristics that the "father" and "mother" possess.

This is mostly true, but there can be an exception where there is a large central seed or pit. Remember that the seed is only half mommy's DNA, so the pollen parent can influence seed size and seed shape. I've seen at least two avocado pollenizer studies that noted pollenizer can have an impact on both fruit shape and seed/flesh ratio, since the fruit shape in avocados is influenced during development by the seed's shape.

[K-Rimes]

The fruit itself will not look any different than the usual parent fruit, but the seed will produce a hybrid of the characteristics that the "father" and "mother" possess.

This is mostly true, but there can be an exception where there is a large central seed or pit. Remember that the seed is only half mommy's DNA, so the pollen parent can influence seed size and seed shape. I've seen at least two avocado pollenizer studies that noted pollenizer can have an impact on both fruit shape and seed/flesh ratio, since the fruit shape in avocados is influenced during development by the seed's shape.

Curious if, like an annona, manual pollination maybe the cause for larger or more seeds.

[NateTheGreat]

I had a giant dragonfruit once from a cross-pollinated flower. I suspect it got huge due to the genetic distance of the parents. I think I saw a study confirming this with dragonfruit once. I think it said only like 17% of the embryos (?) develop into seeds typically, and the amount of flesh is directly correlated to the number of seeds. But no, the fruit shouldn't tell you anything specific about the pollinator, except maybe genetic distance.

[K-Rimes]

I had a giant dragonfruit once from a cross-pollinated flower. I suspect it got huge due to the genetic distance of the parents. I think I saw a study confirming this with dragonfruit once. I think it said only like 17% of the embryos (?) develop into seeds typically, and the amount of flesh is directly correlated to the number of seeds. But no, the fruit shouldn't tell you anything specific about the pollinator, except maybe genetic distance.

The studies I've read show that superior pollination produces larger fruit in DF. This would make sense, as each grain of pollen successfully used will produce a seed and more seeds = more flesh. Let me see if I can find it, it was to do with honeybee pollination https://www.scielo.br/j/rca/a/7KtmqYnxJ5cr6xfybhcsq5C/

Not to say genetic distance doesn't help, but I get some absolutely massive ones sometimes, and other times (same night, same plant(s), same pollen) they are tiny.

[sc4001992]

I let my loquat varieties cross pollinate naturally. But I only plant seeds from the varieties that have the best tasting or largest fruits (Peluche) and hope the seedlings will turn out even better than the cross. I do have over 20 loquat seedlings that have been cross pollinated and so far I have 9 winners. The fruits tastes better than the parent trees (even though I don't know exactly which ones they are), or the named varieties I grow. Since my loquat tree is multi-grafted (80+ var), the fruits get pollinated by the bees from all the varieties on the tree.

[Galatians522]

Studies have shown that seed size in lychee is partly dependant on what the flower is pollinated by. Fruits that were pollenated by No Mai Tze have smaller seeds and a higher percentage of chicken tongue seeds than those pollenated by other varieties. Other than that, fruit quality is the same to my knowledge.

[Oolie]

So does the shape of the pollinated fruit offer hints as to the pollen used to fertilize the embryo to create that fruit? I think the answer to that question is that it depends on the species.

Weirdly it's not a factor for most fruit except Annona like Cherimoya, where the pollen used in fertilization can affect the shape of the fruit as it develops.

That said, it's not a helpful tool most of the time, and you can use techniques to verify the pollen parent by bagging flowers and removing the pollen of the flower after pollinating, but before the flower enters male stage and the pollen dehisces.

Are you trying to use crossing as a tool to learn more about the variety you obtain pollen of?
Otherwise I don't see the use of this tool, and even if that is the goal it seems that it really only plays a factor in fruit shape if I understood what I've read correctly.

Factors like fruit shape don't necessarily play into the progeny though, it depends on phenotypic inheritance.

Some trait genes are dominant, and will more than likely affect the resultant cross. Others can be reflected partway or blended. Some are recessive and are less likely to be reflected in the cross, and may take multiple generations of selection to be reflected in a cross.

Let's take mango seed polyembryony as an example.
The seed polyembryony is affected by a single gene, and the trait is inherited in a dominant pattern similarly to gender in humans. They aren't referred to as "X" and "Y" due to them not having this characteristic shape, but they do follow a similar pattern, so we can call them "X" and "Y" for demonstrative purposes. Similar to how "X" works for humans, the gene that carries the trait for mango seed monoembryony is inherited recessively. Therefore you can get monoembryonic offspring from polyembryonic parents, and at a ratio of 25% if both parents are polyembryonic, and 50% if one parent is monoembryonic. If both parents are monoembryonic the result of their crossing will yield 100% monoembryonic offspring. This discussion only applies to zygotic seedlings.

For typing mango offspring, this is most helpful for determining the the potential parent of a cross. If you have three mango trees in your yard, in this example a monoembryonic type, a polyembryonic type, and a seedling of the monoembryonic type, and it's assumed that no outcrossing is possible, you may potentially be able to identify the parent of the offspring if it produces fruit with polyembryonic seeds. That said, we don't seem to have any mango "breeders" as such, only mango "selectors," and "selectors" don't select on genotypic traits, but phenotypic, or "expressed" traits. You get a lot of confusion when purported parentage of mango selections are espoused, often leading to forum discussions similar to that you might overhear on daytime television.

[pagnr]

Corn is one example where X pollination affects the kernel produced on the resultant cob. Multi coloured corn cobs are so because of X pollination. They are seeds of the next generation, but expressed visually before they germinate. Sweet corn has crinkly seed, and Pollination with maize will produce "regular " seed dent or flint etc.

Kaki persimmon fruit characters are affected by seeds /pollination

"Persimmon varieties are classed either as pollination-constant, meaning that their flesh remains the same color whether they have seeds or not, or pollination-variant, meaning that they develop brown flesh when seeded. Persimmons are also classed either as astringent, like the Hachiya, or non-astringent, like the Fuyu."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4780803/

I think there are further examples of this type of effect in other fruiting plants.

For the most part it is not the case, or subtle as mentioned by others like bigger seeds or bigger fruit due to more seeds.

[tru]

hey I made this thread and then completely forgot and started studying for an exam I had,
Thanks to everyone for the great answers! Gives me a bunch of starting points to learn more about

[mangoba]

Figs can taste better when pollinated with a certain caprifig vs an other. This was the result of a couple scientific research articles.