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Nepenthes Genetics Question (F2 Hybrids)

I'll get straight to the point; has anyone ever seen a Nepenthes F2 hybrid? For example n. (lowii x truncata) x (lowii x truncata).

Now I am no biologist (although I did take advanced bio in high school), but I have a hypothesis on how the traits of each parent would show through. I'm assuming that there is a pair of genes that determines each separate trait of each parents morphology. So, when you look at the upper pitcher of an n. lowii x truncata, specifically the peristome, it would appear (due to size and coloration) that it has received 1 gene for a flared peristome (truncata) and 1 for a subtle peristome of lowii. My hypothesis is that an F2 hybrid could, through the genetic lottery, end up with a full trait of one of the parents. Or most of the traits of one of the original parents could show through with a few of the other parent (say n. lowii with gigantism!).

If anyone has had any experiences with F2 nepenthes hybrids I would love to hear your experiences (or photos!).
Using your example, if you crossed lowii x truncata back to lowii x truncata, the vast majority of the offspring would resemble the lowii x truncata parents not the grandparents. Yes, there would be genetic outliers that may resemble truncata or lowii more than the average, but traits from both parents will still be quite strong. Now, say you continued to selectively breed the offspring that showed more lowii traits, after many, many generations you may end up with a plant that more strongly resembles lowii than truncata but likely you'll never end up with a 'giant lowii' with no visible truncata traits.

Selective breeding is a very long process, it's takes many generations to achieve results as you've suggested. Its also far easier with fast growing plants compared to Nepenthes, which can take years and years to reach maturity and makes the process much slower.
That makes sense that it would take an incredible amount of time to achieve result like what I described. I did some more research and the owner of EP had some experience with F2 crosses and what was interesting was the one he said was most successful was my example! I guess, like you said, hybrids act a lot like species when you breed them together and the offspring resemble the original lowii x truncata cross. He also said the F2 crosses were hit or miss and resulted in some plants with deformities or plants that were very weak and eventually died (sounds like the opposite of hybrid vigor). Makes sense why I've never really seen any F2 hybrids. I was planning on experimenting with it at some point but may be a fruitless endeavor.
Genetics is miles more complicated than "one gene for this, one gene for that" as you're suggesting, and gets even more so the more crossing is done. Many of the traits seen in organisms are not controlled by a single code but multiple coexisting genes or cascade systems, and the traits we see in Nepenthes are no different; to take your peristome example, there is at the least a control for the width of the peristome, the structure of the ribs, the attachment point to the pitcher body, likely multiples for the coloration and pattern, and so on, never minding how one gene may impact another. Cross lowii x truncata with another of the same cross (which I do believe has been done now) and as Mike noted you will get what basically amounts to a bell-curve spectrum centered around the hybrid appearance with some possibly leaning toward either parent but not likely to ever match. Due to the complexity of crossing over between chromosomes and the chances by which any particular pollen grain may meet with any particular ovum, it is a nigh impossibility (chances of billions to one, at the least) that you would get a perfect match of genes for a single one of the ancestral parents,and the lottery for getting an exact mix of traits one is looking for is ridiculous.
Even successive selective breeding may take hundreds of generations to recreate the appearance of a single parent, and if you work with only selected individuals from the cross it would almost never happen because there's no guarantee the selected individuals actually had all gene sets from the one parent conserved among them. Even outcrossing can take forever to return to a parent appearance; Exotica Plants had a set of crosses going, I believe it was ventricosa x talangensis or a similar hybrid, in which they continued to cross plants from each generation back to a pure ventricosa. By the 5th generation or so it was still incredibly obvious that the plants were not pure ventricosa despite only having had talangensis input at the very start and diluted from there.
Everyone's already touched on some great points. There are many complications to breeding Nepenthes - one of them is that there really haven't been enough crosses made for us to understand how the progeny inherit traits from their parents. The slow generation time and the arbitrariness of modern Nepenthes breeding (which boils down mostly to "I've got x coming into flower, who has/wants pollen") is interesting but rarely conclusive compared to advancements in other plant breeding programs, especially for agricultural species.

As already mentioned, Nepenthes traits aren't usually a case of simple Mendelian inheritance; the evidence from breeding suggests most physical traits are controlled by multiple genes and their interactions because the progeny don't segregate into clearly distinct appearances. For example, if we cross N. truncata and N. hamata, we don't see a significant group of N. truncata x hamata without any teeth. It's common but wrong to say "N. hamata teeth are recessive in crosses", and incorrect claims like this only perpetuate confusion as hobbyist breeding becomes more popular.

DNA sequencing has also suggested Nepenthes species are the result of recent hybrid origin since comparing different parts of the DNA can result in very different phylogenetic trees, so we've only really scratched the surface of understanding Nepenthes hybridization (and speciation, which has become a splitter's paradise as of late).

And, plant breeder hopefuls around my university know this chant by heart: the phenotype (physical appearance and characteristics) is a result of the genotype (the genes) and the environment. Environmental factors affect gene expression too, and can affect how we perceive traits to be inherited - a lack of environmental controls as seedlings are dispersed and anecdotes (mostly pictures showing a plant at a single moment in time) can lead to confusion and confirmation biases... (like that crazy old N. robcantleyi thread on the Pitcherplants forum several years back)
Very good points made. In addition, one must also consider the possibilities of mutations .... such as defects during replication of genes or errors in in gene segregation during meiosis or creation of chimeras. Should such errors have occurred in the P1 generation's gametes, there is no telling if one will ever be able to get back to either of the original P1's appearance.

It was actually incredibly lucky -- and fortunate for the field of genetics -- that Mendel happened to choose pea plants which had very simple dominant/recessive traits.