pod vs pollen influence on trait inheritance?

I was wondering whether there are any "rules of thumb" concerning dependency of trait inheritance on whether a parent in a hybrid is the pod or pollen parent?
My query is about the whole plant not just the flower. Does anyone of you have any ideas. I ask because I recently read something that inferred (indirectly) that the flower stalk length will be closer to that of the pod parent than the pollen parent. Is this true ?
Cheers,
Tim

I ain't no breeder. but I hear that color is frequently more influenced by the pod, since (presumably) the bulk of the plastids are inherited from that parent. mitochondria too but not sure how that influences the flowers...or perhaps growth traits, who knows.

it makes sense that various traits can be differentially inherited from the "mother" and "father," because this certainly occurs in animals, and even people. there are some diseases that can only be passed down from either men or women. this phenomenon is known as genetic imprinting, and the most famous example of this is Angelman syndrome and Prader-Willi syndrome. Same mutation, totally different results based on which parent passes it down.

unfortunately, I can't give you a specific answer for the situation you described, but hopefully someone knows.

ScottMcC said:

it makes sense that various traits can be differentially inherited from the "mother" and "father," because this certainly occurs in animals, and even people. there are some diseases that can only be passed down from either men or women. this phenomenon is known as genetic imprinting, and the most famous example of this is Angelman syndrome and Prader-Willi syndrome. Same mutation, totally different results based on which parent passes it down.

unfortunately, I can't give you a specific answer for the situation you described, but hopefully someone knows.

Click to expand...

Yes genetic imprinting (of different methylation patterns of DNA in sperm vs ovum)definitely occurs in humans and there are multiple examples. There is even some data (although in rats) to suggest that parts of IQ might have some imprinting effects. Hard to measure in humans because besides siblings spouses have the most similar IQ.
An important concept in imprinting is that it has to be erased and reset with each generation, so that with each generation the imprinting is consistent with the sex of the parent, not the grandparents. For example, in a male a maternally imprinted allele loses the maternal imprinting in the male's gametes, so that when this allele is passed on to the male's offspring it is not imprinted and is active. Conversely, in a male a paternally imprinted allele will be imprinted in the male's gametes, and therefore the gene passed on to the male's offspring will be imprinted and inactive (the maternal copy will be expressed and be active). Thus, the gene must be marked (or imprinted) in a way that can be altered from one generation to the next. How this occurs is not clear
In the end both mother's and fathers genes get passed on ultimately they might just be expressed to different extents depending on the whether a their future generations genes were passed on from a man or a woman. Like if a male has a daughter than his genes that are imprinted will get be expressed differently in this future generation than in his progeny.

Anyways this is a really great topic and I am interested in what people have to say. If traits are similar to human imprinting. We may have to look at the parent's parents because in the next generation the pollen's genes can go to the pod and pod's to the pollen

Wow! I've often wondered about this and although I have NO experience w/ hybridizing I am interested in any studies involving switching parents. E.

I am hoping someone well experienced in breeding will pop in here and give us a list of characteristics that each parent passes on. For example...

Color- pod
Growth Habit- pollen

Something similiar. But I have a feeling it may not be that simple. You do see reciprocal crossing from breeders because of the variability in many crosses.

I have also heard breeders speak about crosses, and how they know what the final color of the bloom may be, because they know which colors are dominant over others.

For example, if you cross a flower with a blue lip with one that has a white lip, and the offspring have a blue lip is that because the coerulea color strain is more dominant than white? And if so, what are the other "rules" of color in breeding?

only thing i've noticed is that mastersianum doesn't seem to influence color too much, but makes the flowers waxy. i ain't never made a cross, though...

some of this may be 'trade secrets' (stuff like it's easier to bloom hybrid a when species c is the pod parent instead of species l). i'm curious as to what answers are to come...

From my discussion with Phrag breeders and my own limited experience, it seems that flower size and shape are more likely to be strongly influenced by the pod parent.

For example, I was considering buying a couple of Phrag flasks last year: Ackers Superstar 4N x Mem. Dick Clements 4N, versus Mem. Dick Clements 4N x Ackers Superstar 4N. I asked the breeder what he expected the difference to be, and he replied that Acker's Superstar is a larger flower, and if it's the pod parent, the size will more likely be passed on.

This does seem to be dependent on the species, though. For example, I've also read that Phrag schlimii tends to pass on its color very strongly, regardless of whether its the pod or pollen parent, and my experience with schlimii hybrids seems to confirm that. The same seems to be true of certain hybrids... Barabara LeAnn, I think, passes on its color in the same way.


- Matt

you can find some info here:
http://www.geocities.com/~marylois/archiv61.html

OK , here are some of my experiences (as being an orchid breeder).

In most cases I have noticed that it does not make too much of a difference if you use one parent as a pod or as a pollen parent. I usually do it both ways, so I have double the chance of getting a seedpod.

The only time it would make a difference if it involves genes that are in the plasma of a cell. They only get transmited through the next generation in the egg cell, so when you would use that as a podparent. Now you have to remember that more than 99% of the DNA is in the nucleus. There is only a small percentage of DNA that gets inherited through the plasma (mitochondrial or chloroplastic DNA).


Now I know with breeding Paph's people have told me if you make a brachy x multifloral cross. It is better to use the brachy as the pod parent. If you do it that way you getter better shaped flowers. I don't know if this is true or not.

Also I have heard that if you use Paph. delenatii, it is better to use it as the pollen parent. Paph. delenatii has dominant genes, that are probably in the mitochondrial DNA that makes the colors lighter; it washes them out, so if you use delenatii as the podparent the offspring will be lighter in color than when you use it as the pollen parent. That is why when you make Paph. Magic Lantern it is better to use Paph. micranthum as the Pod parent; you get darker flowers that way.

Also out of own experience we have noticed when we make Phrag. Jaosn Fischer it is better to use Phrag. besseae as the Pod parent. The flowers tend to be better shaped, than if you use Phrag. M. D. Clements as the pod parent.

when it comes to yellow pigments, I have also heard that some of them get inherited through the mitochondrial DNA, so if you are breeding for yellow colors, it is better to use the yellow flower as the Pod parent. I do not know if this applies when using Phrag. besseae flavum, or Paph. armeniacum.

Another thing you have to keep in mind when breeding two flowers that are different in size (think like a Phrag. fischeri or Phrag. schlimii versus a Phrag. caudatum), is that you get a better seedset, when you use the smaller flower as the podparent. This is because the pollen tubes of the smaller flower won't be able to grow as long as the pollen of the larger flower, so if you pollinate a Phrag caudatum with a Phrag. schlimii only the top part of the ovules will get pollinated.

Well I can write whole epics about this topic, but I have to get back to work.....

Robert

More good information. Unfortunately this reminds me of why I dropped my plans to go into human genetics counseling. Maybe I'm old fashioned but talk about anything but one aspect of reproduction makes me dizzy. :viking: When my head stops spinning can someone stand me back up please?

relative influence of pod and pollen parents

This question raises a LOT of issues and I don't have time to mention all of the ones with which I am even mildly aquainted. I am no geneticist, but those of us who have been hybridizing for a while have run into this issue for years. The simple answer is YES - there are differential influences from the pod and pollen parents. The most significant factor is that of cytoplasmic inheritance. Not all the genetic material transferred in the process of fertilization is due to gene transfer from inside the nucleus of the pod parent. Most of the information about this has centered around Phalaenopsis hybrids - particularly yellows, where the yellow pigmentation is influenced primarily by genetic material that lies outside the cell nucleus. I will see if I can find some references of research and post them here later. Off to see why my high-tech German boiler keeps belching and shutting off..

From what I've read, color expression of greens and yellows has a great deal to do with which pod parent is used. Here's a bit of a longer mildly-related answer from a thread on the 'other' forum:

Most flower colors are a result of four different pigments - chlorophylls, carotenoids, flavonoids, and betalins.

Chlorophylls and carotenoids are oil soluble and located within some plastids in the cytoplasms of the cells. Chlorophylls are green and carotenoids are usually yellow. Plastids have their own genome and are inherited exclusively from the pod (female) parent. However, nuclear DNA, which is inherited from both parents, often plays a role in regulating carotenoid synthesis.

Flavonoids and betalins are water soluble and located within the vacuoles of the cells. These two are generally responsible for red through blue colors. Betalins are rare and not produced in orchids. The flavonoids can be broken down into anthocyanins and co-pigments. The production of flavonoids is regulated by the nuclear DNA. The color of flavonoid-containing cells depends on the combination of anthocyanins and co-pigments produced in a cell along with the pH of a cell. As the pH increases, the color produced is bluer, as it decreases, the color produced is redder.

--Stephen

silence882 said:

The color of flavonoid-containing cells depends on the combination of anthocyanins and co-pigments produced in a cell along with the pH of a cell. As the pH increases, the color produced is bluer, as it decreases, the color produced is redder.

--Stephen

Click to expand...

Which is why if your soil is more basic/acidic your hydrangeas are more blue/pink, right? So, if you can change the color of your hydrangeas by changing the pH, why can't we do that with other flowers?

Heather said:

Which is why if your soil is more basic/acidic your hydrangeas are more blue/pink, right? So, if you can change the color of your hydrangeas by changing the pH, why can't we do that with other flowers?

Click to expand...

We can! Just not easily. It could be that cellular pH is especially easy to manipulate in hydrangeas by manipulating medium pH. That is probably not the case in the slippers. In order to raise or lower the cellular pH intentionally, one can breed based on the relative pH of plant blooms. Rob Griesbach published an article along those lines in Orchids a year or two ago.

--Stephen

Hmmm, someone should work harder on this. I could go for being able to change a few of my besseaes blue.

...I believe an Alzheimer's medicine was used to make pure blue flowers on rose plants...

This is very interesting. The pH inside the vacuole is not necessarily the same as the cytoplasmic pH. For those that remember their cell biology hydrogen ions do not cross a membrane unless there is a transporter (or trans-membrane ion pump). Theoretically you could cheat ... if you could isolate a promoter (gene switch) that is active in flower parts but not in the rest of the plant ... you could target an ion pump to the vacuoles by genetic engineering. If in addition you had an inefficient/slow ion pump the flowers could open red and turn blue with time. :wink:

OK, OK ... and elephants might fly ... and this really is a can of worms. If the enzymes that produce the pigments are in the vacuoles and are also pH sensitive they might just stop working.

Don't take me too seriously.
Cheers,
Tim