The Tropical Fruit Forum

I stand for plant genetic identity preservation and i think this "true to type" seeds thing causes a lot of damage and confusion in this regard. You can have a clone from a seed but that's probably the worst way to do that and you are probably not able to identify it with high confidence. People often do this because seeds is all they can get, so they don't even own the original plant to compare with. If you want to do this for fun, that's great, but if you don't have the means to do the proper identification, please keep your plant for yourself, don't sell or share genetic material as if it came from the original plant

Citrus seed has routinely been use to transfer Citrus varieties around the world in the past.
There is a high level of success in obtaining known varieties, and with knowledge of variety characteristics, off types can be rouged out at later stages.
Seed is easier to send with transit delays, compared to budwood.
More importantly seed is essentially virus free, whereas budwood often contains virus, or bacterial pathogens.
There is more skill required in growing rootstocks and grafting trees, compared to growing from seed.
Ideally both processes(  seed propagation and grafting )should be followed, as back up to each other.
There is always some risk of variety drift with seed propagation, leading to seperate lines of a variety in different areas.
This is also possible with budwood, more so with some types of Citrus than others.
Bud sport mutations have lead to many Navel Orange varieties, even bud Chimera hybrids are known, where two types fuse into one bud creating a " hybrid " tree.
I think there is a need to balance variety preservation with genetic change and increased diversity.
If new variety types are clearly designated as such, I don't see such a problem.
Maintaining overly strict variety identity can lead to them to become genetic artefacts.
This has its good points, for preserving genetic diversity, and for cross breeding.
Many varieties have also lost their use purpose or utility in later years, ie Cider Apples, Storage Apples, Citrons for candied peel, Seville Orange for Marmalade Jam.
These varieties still exist, but have largely lost their use and popularity in modern times.

A very strange choice by AusCitrus of using highly zygotic strain of poncirus for rootstock propagation.

Now that you mention it, a large group of their Poncirus seedlings in the same pot media ( same pot ) have quite a range of autumn colours before leaf drop, some plants yellow, some orange some red. Another indication of the same variation ??

In the woods this weekend I came upon a grove of poncirus. I spent some time looking for variations/mutations. Nothing of real intetest except part of the grove had large fruit.

In Australia, Citrus are mainly propagated from approved seed and budwood from AusCitrus. Poncirus trifoliata seed are from one particular strain in the scheme.
After finding an abandoned orchard, where the Poncirus rootstocks had taken over and fruited, I did notice a wide variety of fruit sizes on those trees, and some differences in the smooth /crinkly texture of the peel. Since the orchard was all the same variety of Citrus and about ten years old, I assume all the trees were planted at the same time from the same source. Conclusion, seedlings from one Poncirus tree can produce an array of fruit size variation.
It is likely the large fruited variants are exactly that.

I have an Osage orange across the street from me

It is interesting that there is a similarity to these Australian species,
Wild Bush Orange Cappiris canescens and Cappers mitchellii.
Both Osage orange and Cappiris linked to extinct Megafauna to distribute seed from hard fruits.
https://herbalistics.com.au/product/capparis-mitchellii-wild-orange-plant/

Pagnr, can you elaborate on the concern about open pollination not yielding the desired results?

My point is that I am in a Citrus growing area, and often collect Citrange, Swingle, ( also Rough Lemon ) fruit from seeds for rootstocks from various garden trees,
where the rootstock has taken over, or partly taken over, ( so there is a half rootstock half scion fruiting tree ).
As these trees are usually in gardens with other Citrus, there should be opportunity for random cross pollination.
I don't think I am seeing any significantly different seedlings to indicate this happens.
For commercial rootstock seed production, trees are in arboretums or rootstock tree seed blocks.
Again there should be ample opportunity for cross pollination.
From these rootstock seed trees, tens of thousands of Citrus rootstocks are grown.
There are issues of off type zygotic seedlings, more or less % with the various types of Citranges.
I don't think there is any issue with rootstock seed being out crossed to neighbouring trees.
Some Citrange types produce higher % of zygotic, but these don't seem to be outcrossed, they are off types of the same variety.
Zygotic seedlings do not necessarily need to be the result of outcrossing to another Citrus, they can be self crossed to the same variety, possibly the same flower.

There may be flowering period timing issues as to why the outcrossing is not seen, ie the flowering period of two adjacent varieties does not overlap enough.
Also there may be pollinator behaviour issues. Bees may not move between trees, but work the same tree and rarely hit another tree to X pollinate.
When seed saving heirloom vegetable varieties at risk of X pollination, there are strategies to reduce this by interplanting other species to buffer the pollen movement by bees.
For mixed rows of Fava broad beans, type A type B type C, if you only collect seed from the middle of each type, it is unlikely that bees have jumped between types along the same long row. Only the adjacent plants in the row are likely to be crossed. If you plant peas between the broad beans types in the row, the chance of X pollination of varieties is further reduced due to bee movement behaviour.
There may be ways to reverse this and optimise  X pollination.

Secondly with random pollinations, you will have no idea where any successful seedlings have originated, parent wise.
You may be able to guess the parents from characteristics, but if you want to repeat a cross to get more versions of the same, you will have to start from scratch.
Another point to consider is the way you grow out the seeds.
If you mix all the seeds from all the fruit from one tree and grow them in one lot, you will see random odd seedlings.
If you grow the seed from each fruit separately in its own pot, you can track pollination events and related crossed seedlings.
ie if you grow a container of 100 citrange seeds from ten fruit and find 7 off types, you will have an off type rate of 7/100.
If you grow the seed of each fruit separately, you may find that 5 off types came from only one fruit, and are likely X pollinated ??
The other 2 off types may be both in lots from different fruit, and are likely zygotic.
Hopefully you can then distinguish the characteristics off off type zygotic vs X pollinated seedlings.

Initially you may not want to extensively X pollinate, as it is a lot of work.
You may be able to filter results by separating seed lots by fruit extraction.
You may find differences in % off types, vigour, disease resistance.
If you mix all seeds from all the fruit from all trees in one season, you will have random unrepeatable results.
The more you seperate the seed lots, the more you can see patterns.
Labelling is very important, it can be hard to keep track of what's what as they build up.

lajos93. can you remind us as to what Avocado variety seed you already have, or are able to access from fruit in local shops., or other European shops.

Apart from genetic variegation, there is also viral variegation and fungal seedling albinism.
Viral variegation often hits only one leaf. Fungal albinism can hit new emerging seedlings. It can be hard to tell if the seedlings of variegated Citrus are genetic or Fungal albinos.
There was also a report that Pythium fungal infection can induce genetic mutation in Poncirus seedlings at emergence, causing off type, stunted seedlings.
Poncirus Williams strain was said to be resistant to this.

I think you would be better to get scions of the most cold hardy varieties and cross pollinate them to maximise the tolerance factors from all parents into the seedlings.

I remember reading that Microcitrus is fairly close to Fortunella on the family tree. Does that still hold up to recent analysis ?

ok, this is off topic so I wil not continue to post more photos here, this is for sumo seedling. So go to my other post I started and I will show you some of the seedlings of FD.

I found the pics by searching your posts, but I can't find the post.
I am not seeing any major differences in your FD seedlings, just normal variation, none look like a Poncirus X Citrus hybrid.
Off type FD are interesting if you find them.

Most fruit tree seeds are true to type, and most members would have propagated many from seed to get pretty close to what they wanted.
Wild species and non hybrid cultivars are pretty much in this zone.
Hybrids and improved cultivars will likely throw more variable seed offspring.
The wider the hybrid cross, the more likely to get more variable seed progeny.
F1 hybrid fruit will normally give variable F2 seedlings.
Not all hybrid varieties are actually true F1 ( AABB X aabb = AaBb hybrid )
Variety cultivars may give similar but variable seed progeny.
I had a nice white peach, maybe Okinawa, that volunteered quite a few seedlings. The fruit was pretty much identical to original, but the ripening time was different by weeks and months. One seedling is so late it can't ripen before winter.
Found seedlings of Apples on roadsides can be variable, but mostly pretty similar to the seed in the core that came out the car window.
There are also many myths about "not being true from seed".
In most cases you are going to get something pretty close to the fruit the seed it came out of, some might be real duds, but most variants will be edible.
Species and cultivated varieties might need more info beforehand, if you don't have time and space to wait for results.
Some varieties from some species have nucellar / polyembryonic seeds that are clones of the parent ie some Citrus and some Mangoes.
Where seedlings are used as grafting rootstocks, the level of seedling variation is low enough to allow fairly uniform similar rootstocks.

I found a variegated lemon in a carpark, it produces a mix of normal and albino seedlings, from two or 3 seeds per fruit.
There was a method of maintaining albino seedlings by feeding sugars /carbohydrates. If you G search that you mind find the info Scientific paper.
Nucellar albinos will be no different to non albino nucellar, so maybe not worth the effort to save ?