Apomixis in Orchids

[orchidsarefun]

for a bit of background to apomixis read this
http://www.public.iastate.edu/~mbhat.../diversity.pdf

I have a request - help!
I carried out an intergeneric cross and have just found out that there has been seed germination in the flask. By all accounts the cross should be impossible.
However I found out via another forum that the pod parent could be apomictic, but no further info could be obtained.
Can someone help with specific info ? The pod parent plant is a hybrid of Aganisia Cyanea ( formerly Acacallis ) and a Zygopetalum. Do you know if any of these are apomictic ? Do you have a source, or can post a link ?

Another interesting fact is that I subsequently backcrossed the pod parent to another ( different ) Zygopetalum and the pod was sterile !

---------- Post added at 10:18 PM ---------- Previous post was at 09:02 PM ----------

I came across this article too and have e-mailed them for info...

Understanding Apomixis: Recent Advances and Remaining Conundrums

quote
"Apomicts are found more commonly in habitats that are frequently disturbed and/or either where the growing season is short, such as arctic and alpine sites, or where other barriers operate to inhibit the successful crossing of compatible individuals, such as among widely dispersed individuals within a tropical rain forest (Asker and Jerling, 1992)"

the highlighted part is salient because I have read that Aganisia sp. can spend a large part of their life cycle under water, during Amazon flooding.

[lambelkip]

what pollen parent were you trying to use?

[King_of_orchid_growing:)]

Originally Posted by orchidsarefun

for a bit of background to apomixis read this
http://www.public.iastate.edu/~mbhat.../diversity.pdf

I have a request - help!
I carried out an intergeneric cross and have just found out that there has been seed germination in the flask. By all accounts the cross should be impossible.
However I found out via another forum that the pod parent could be apomictic, but no further info could be obtained.
Can someone help with specific info ? The pod parent plant is a hybrid of Aganisia cyanea ( formerly Acacallis ) and a Zygopetalum. Do you know if any of these are apomictic ? Do you have a source, or can post a link ?

This is the closest I can find, if you haven't gotten a hold of it already.

https://atbc.confex.com/atbc/2013/we...Paper2124.html

Originally Posted by orchidsarefun

Another interesting fact is that I subsequently backcrossed the pod parent to another (different) Zygopetalum and the pod was sterile!

I came across this article too and have e-mailed them for info...

Understanding Apomixis: Recent Advances and Remaining Conundrums

quote
"Apomicts are found more commonly in habitats that are frequently disturbed and/or either where the growing season is short, such as arctic and alpine sites, or where other barriers operate to inhibit the successful crossing of compatible individuals, such as among widely dispersed individuals within a tropical rain forest (Asker and Jerling, 1992)"

Don't know what to say about this. Hopefully you'll have your question answered.

Originally Posted by orchidsarefun

the highlighted part is salient because I have read that Aganisia sp. can spend a large part of their life cycle under water, during Amazon flooding.

It is true. Acacallis (Aganisia) cyanea spends part of their life cycle partially submerged in water during the summers. This is why they are one of the most difficult and frustrating Zygopetalinae to grow.

[Ray]

One often hears that "any cross made with a zygopetalum will look just like the zygo", so there may be something to it.

[orchidsarefun]

thanks for the replies and to K.O.O.G for that link that seems to confirm that old saying. I feel sorry for the breeders in the "old days" that didn't have the knowledge of apomixis and its material impact on crosses.
Especially this guy - who did a lot of zygo intergeneric experimentation I am told.
John Banks at Wyld Court Orchids

I had noticed that intergeneric crosses with zygos or aganisia result in the progeny being visibly close to, but not quite the same, as the zygo or aganisia parent. Aganisia x Zygo favours the Aganisia side though.

OrchidWiz photos are invaluable !

It appears that with apomixis there can be a genetic contribution from both parents if cross-pollinated, but limited to certain characteristics only ? ( judged by progeny )
I am not sure what to conclude about my cross. On the one hand I have tried to backcross my zygonisia with a zygo ( failed ), self ( failed - 2x different zns ) and on the other hand a cross with an intergeneric that "isn't possible", triggered apomixis......maybe.
Its a long wait to see these seedlings bloom, and its true that the cultivation of zns is not straightforward. Its going to be a challenge.

[orchidsarefun]

found this, interesting in itself as an example of a patent application.
My pod parent is this orchid cultivar

EXOTIC ORCHID 'Blue Birds' - Patent application

and this extract:

[0049] Seed.--seed production, while attempted, has not been successful.

[orchidsarefun]

I'm bumping this topic again in the hope that there is new input/insight.

I have used this same pod parent again with 2 separate intergeneric crosses. Both are successful in that pods are developing very well. I was extremely careful in removing the pod parent pollinia and I am certain that a selfing was prevented.
A 3rd intergeneric failed - and that is the interesting part because if the other 2 were as a result of apomixis, then a logical conclusion is that this should have been successful too ?
My seedlings mentioned in the OP are still at the lab. Unfortunately it will be a number of years before I can prove/disprove anything !

Does anyone know if Aganisia spp. are capable of apomixis ? Has anyone come across this topic before ?

[Fairorchids]

1. I have never heard of this condition in orchids. The study referenced talks primarily about grain plants, not orchids.
2. Dominance of traits from one parent proves nothing, other than one being dominant over the other.
3. Trait dominance can vary, depending upon which plant is carrying the pod. That's why doing a cross both ways is recommended.
4. That one out of 3 or 4 similar crosses fails proves nothing. It happens.



There are some species that self-pollinate readily, but that is another issue.

[orchidsarefun]

Originally Posted by Fairorchids

1. I have never heard of this condition in orchids. The study referenced talks primarily about grain plants, not orchids.

Actually it was a well known breeder who runs a specialised orchid forum who alerted me to the possibility, but couldn't provide specifics. I just want to know if anyone else can provide pertinent input on this issue.

[GluttonousSolarWrasse]

Apomixis also occurs in many citrus and some poacea. It arises from a somatic cell within the ovary dividing and differentiating (like any fertilized ovule). Since it arises from a somatic 2n cell, and grows/divides by mitosis any potential offspring arising from apomixis would be clonal-genetically identical to the parent. Any phenotypical difference could only be explained by environment as the genes and the cytoplasm come from the same source i.e. there should be no differences even explained be cytogenetic interactions. Apomixis can and will occur in the same ovary right alongside an outcrossed ova. And it may not occur in every ovary every time. (I.e. obligate apomicts can and do outcross), so your pod parent plant could be an apomict, have 2 apomict pods, and the third-your cross could have cross took, then aborted. If the vast majority of your offspring are identical to the parent, you may have an apomict (which would be sick!)