Hi y'all!

So I've read alot on the history of breeding the complex white paphs, from F.C. Puddle to Skip Bartlett to White Knight. I don't exactly understand the mechanism of color suppression in Paphs. Could someone help me understand this better??

Also, I recently bought a nice little Paph. Nimit (Greyi X primulinum). A wonderful, nicely formed flower. Wide petals, nice dorsosepal, and just a very few fleck of the oxblood that one finds in the whiter brachypetalum crosses. And also with the wonderful trait of being a sequential bloomer, on its third flower. I'd post a pic, but the flower got sort of beat up on the trip home from Tampa, and I've cut the pouch off (I've crossed it with Lady Isabel). Has much hybridising been done with whites and the multi-florals, either sequential bloomers or true multi-florals? The only one I really know of is Paph Wild Thing (check In Charm's website). That's the next thing I'm crossing Nimit with.

Where's Ross??? He does the complex breeding thing. I just wanna see pretty pictures.:D All I know is that crossing delenatii with armeniacum suppressed yellow and pink and makes an all white paph. :confused:

I'm not into hybridizing but very interesting question nonetheless and I too would like to know the answer.

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.

There are some species of Paphs which seem to have the ability to suppress plastid color expression. Paph. niveum and to a lesser extent its brachy cousins, Paph. godefroyae and Paph. bellatulum, are among these and have played the biggest role in this area in white-complex breeding. Paph. delenatii also has the plastid-suppression ability, but it hasn't played a very large role. I believe there have been fertility issues with F1 delenatii hybrids which have limited its role in complex hybridizing. Teresa's example of Paph. Armeni-White shows Paph. delenatii 'washing out' the yellow color of Paph. armeniacum.

The source of the flavonoid color-suppression is a bit murkier. I believe it comes from the use of Paph. insigne fma. sanderae in early complex hybrids. It is important to note that fma. sanderae is the near-albino that has dots on the dorsal sepal. For example:
http://www.slipperorchids.info/paphspecies/Paphinsigne(fma)sanderae6.jpg
This is different from the true albino, fma. sanderianum:
http://www.slipperorchids.info/paphspecies/Paphinsigne(fma)sanderianum1.jpg

To obtain a pristine white, breeders cross a flower that shows plastid color suppression with a flower that shows flavonoid color suppression. Usually the plastid-suppressor is used as the pod parent, but it can work either way.

The earlier generation complex-whites are brachys crossed with complex hybrids containing a high % of insigne fma. sanderae. The brachys contribute the plastid color suppression and the complexes contribute the flavonoid color suppression.

Many of the modern complex whites are made by crossing large standard-complex greens and yellows with earlier-generation complex whites. The greens and yellows contribute flavonoid color suppression while the complex whites contribute plastid color-suppression.

One of the best modern white-complex paphs is Paph. White Knight. It was made by crossing Paph. Skip Bartlett (white-complex) with Paph. Green Mystery (large green-complex). Paph. White Knight was then crossed with Paph. Elfstone, another large green-complex, to make Paph. Mystic Knight. Paph. Mystic Knight is often regarded as the best white-complex paph yet made.

It is important to note that white-complex breeding is utilizing color-suppression genes and not albinism genes. Albinism results from a defective gene somewhere in the chemical pathway within the cells that produce flavonoids. As a result, the red through blue colors are not expressed in the plants or flowers.

--Stephen

Where's Ross??? He does the complex breeding thing. I just wanna see pretty pictures.:D All I know is that crossing delenatii with armeniacum suppressed yellow and pink and makes an all white paph. :confused:

I rarely do any crosses with multiflorals. I'm just a maniac with a limitless supply of toothpicks and some hopes as to what my crosses will produce. I cannot pretend to be anything more than that. Stephen's reply is much better than anything I can contribute.

I'm just a maniac with a limitless supply of toothpicks

For some reason, this phrase made my day! :D