I have a question for anyone who may know. Does anyone know what the ploidy level is of most complex Paph's (Like Paph. Winston Churchill and Paph Elfstone etc.). I am wondering if they are all tetraploid or if some of them may be hexaploid (6x).

The reason that I am wondering, once in a while if you cross a diploid brachy onto a complex most of the offspring tends to be fertile. If the complex was a tetraploid, the complex x brachy would all result into triploid plants (and you would assume that most of those are sterile). However, if the complex is a hexaploid, if you cross it with a regular diploid brachy, your resulting offspring would all be tetraploid and thus fertile.

Any ideas?

Robert

not sure of the answer but being triploids are generally not particularly good breeders because they are not particularly fertile. To complete the cycle, one could double the ploidy of a triploid to make a hexaploid (6N). The hexaploid would be more fertile. So Paphs that were triploids may have been converted to hexaploids to be used for breeding.

I believe Winston Churchill 'Indomitable' clone is a tetraploid.

I haven't seen actual chromosome counts for complex hybrids, but many apparently are polyploid. There are a few plants such as Paph insigne 'Harefield Hall' that are triploid but fertile. Also, evidently some plants are aneuploids due to species backgrounds that have different chromosome counts. This seems to account for distorted flowers and crinkled foliage in some plants. It also makes them less fertile.


This has been a barrier in breeding white hybrids with the exception of Paph F.C. Puddle and its progeny until very recently. Also, I would guess that perhaps some of the yellow/green flowers might still be 2N even though they are quite large.

Without seeing the counts for these plants it is all conjecture, but since Paph Winston Churchill seems to be quite fertile I would concur that it is probably 4N.

The hexaploid question is interesting and would be a fun experiment for someone with more time on their hands than me! Although your answer is logical, that doesn't mean that it occurs that way in practice......

Wow. I was lost after the second sentence...LOL :p
I have never even heard of a hexaploid. But it seems that it is possible!

Excuse my ignorance...how exactly does a hexaploid come about?

Excuse my ignorance...how exactly does a hexaploid come about?

A 4N plant crossed with a 2N plant results in a 3N plant. If you colchicine treat the resulting embryos of that cross you end up with a percentage that will be hexaploid, 6N.

3N plants are not very fertile, although there is usually some pollen that will be so they are better used as the pollen donor. 6N plants are fertile. So, it would make sense that if you are going to be breeding a plant that will be 3N...go for the hexaploid.

The complex paphs are polyploid.

Read that again.

The complex paphs are polyploid.

The reason I say it this way, is because it is the last statement about the chromosome number of bulldogs that is unequivocally true. And maybe then, only if you consider normal chromosome numbers polyploid. Every other statement you hear about the ploidy of complex paphs has more than one exception. Most CPs have some interesting and odd (and often uneven) chromosome number. The facts:
1) Not all of the original species used to create them aeons ago had equal chromosome numbers, resulting in odd chromosomal pairings. This is why whites were/are so poorly fertile.
2) Triploids are sometimes fertile, resulting in interesting chromosome numbers in these offspring.
3) The mechanics of chromosomal division during the development of ova and pollen are complex enough to allow for mistakes, which sometimes results in polyploid offspring from diploid/triploid parents. Hexaploid bulldogs were created in this way, not (to my knowledge) through colchicine treatments (speaking of which, did the EYOF colchicine treat any Paphs when they did their work with phrags back in the 80s-90s?).

Thanks for the explanation Ron.

Don Wimber helped creat a number of 4n paphs at The EricYOF as well as a number of 4n Phrags. These 4n plants were responsible for increased fertility in a number of breeding lines and are still being used today.
Hexaploid Paphs, Phrags and even Phals are not very good growers and usually not very good breeding plants. The high number of chromosomes results in increased aneuploidy and resultilng infertility of progeny. It is best to stick with 2n and 4n plants for breeding and when making interspecific hybrids using species with different chromosome counts it is desireable to use 4n parents. 3n plants often have very good growth and flowering characteristics and while often desireable, are not the way to go in hybridizing.
Dean

The complex paphs are polyploid.

Read that again.

The complex paphs are polyploid.

The reason I say it this way, is because it is the last statement about the chromosome number of bulldogs that is unequivocally true. And maybe then, only if you consider normal chromosome numbers polyploid. Every other statement you hear about the ploidy of complex paphs has more than one exception. Most CPs have some interesting and odd (and often uneven) chromosome number. The facts:
1) Not all of the original species used to create them aeons ago had equal chromosome numbers, resulting in odd chromosomal pairings. This is why whites were/are so poorly fertile.
2) Triploids are sometimes fertile, resulting in interesting chromosome numbers in these offspring.
3) The mechanics of chromosomal division during the development of ova and pollen are complex enough to allow for mistakes, which sometimes results in polyploid offspring from diploid/triploid parents. Hexaploid bulldogs were created in this way, not (to my knowledge) through colchicine treatments (speaking of which, did the EYOF colchicine treat any Paphs when they did their work with phrags back in the 80s-90s?).


I Agree!!:iagree:

Ramon:D