Hybrids and crossing principles

[DavTom]

Hi,

Sorry if there is already a thread covering this topic, but I could not find it.

Does anyone know a website or published article, etc... in which it is clearly explained:
- what are the easy crossings that do produce a plant that will produce fertile seeds (I am not interested in the obvious ones like Phals with Phals)
- what are the less easy crossing that produce a plant that may or may not produce fertile seeds
- What are the more difficult crossing that may or may not work at all

Examples/pictures of crossings would be a plus. But I am much more interested to know what are the applicable principles as I found a lot of confusion on internet about tribes, sub-tribes, genera, not to mention alliances, etc...

For instance, I have read that Vanda with Phals is a non easy but doable cross.

Many thanks in advance.

Dav

[Ray]

I'm certainly no pro in this area, having made only a few crosses, but two significant factors are chromosome number (total of all sets) and ploidy (number per cell).

The closer the median number of chromosomes, the more likely a cross will "take". (Chromosome Count Database)

As far as ploidy is concerned, like people, orchids have paired chromosomes, i.e., 2N. Sometimes, either through a natural or chemical-induced alteration, you'll get double that, 4N, or tetraploid plants. A 2N breeding with a 2N is fine, as is 4N with 4N, and the plants are all fertile and can breed. if a 2N is crossed with a 4N, you will usually end up with 3N (aneuploid) plants that are sterile, so cannot breed.

[DavTom]

Thanks Ray!

I will start from that.

Dav

[Ray]

I just thought of another factor I had forgotten - “size matters” - at least when crossing plants having dissimilar sized blossoms.

When you place the pollinia on the stigmatic pad, the pollen grains “germinate” and grow a pollen tube down to the ovary, so that the genetic material has a travel pathway.

The length of the pollen tube is related to the size of the flower from which the pollen originated, so putting pollen from a small flower on a large flower reduces the chances that the tube will reach the ovary.

I recently read an article that showed that the application of KelpMax/Kelpak accelerates the growth of pollen tubes, which often increases the number of successful “matings”, but I don’t know if it can affect the tube length.

[tmoney]

as my tag says, im a total noob to all this, but am also interested in your question and read a lot (and am a biology teacher, which helps). the only thing i have definitely learned is that mini mark (i know....a phal), has never produced a cross as the pollen parent. something something they may be triploid. so, for me at least, it’s easier to know what won’t work and the rest become pure possibility.

you can gain a lot of insight by looking at cross lists and see what common parents and crosses are (species at least, not even gonna wade into complex hybrid territory here). then process of elimination to work backwards from what is NOT seen

edit to add that if you have a little science background and can understand some of the lingo, there are a ton of academic journal articles that deal with this sort of stuff. but searching those can be exhausting if you aren’t used to it

dang it! second edit to add my fav link below, which if you click any species it will give you a list of some hybrids. i have found it a good way to at least identify easy intergnerics you might try. that can provide more insight as well. i know, sorry, it’s all phals....but gotta start somewhere, i suppose!!

Phalaenopsis classification by Olaf Gruss & Manfred Wolff

[RoseSD]

While on this topic can I ask which ones of you great people hybridize orchids for hobby or work? Do you pick one specie to focus on, or do many kinds? How expensive is this hobby?

[TZ-Someplace]

This video from the 6th Annual Cattleya Symposium taught me a great deal after I already thought I understood things. The latter part is probably more of what you are interested in.

[Fairorchids]

This is a very large subject. As Ray mentioned, triploid (3N) plants are usually infertile.

In the broad Cattleya family (incl. Brassavola, Broughtonia, Epidendrum, Laelia, etc.), all species have the same number of chromosomes, so intergeneric hybrids are generally fairly easy to produce.

In the Paphiopedilum genus, the number of chromosomes varies, so here hybrids can be much more difficult to produce. And, some 'successful' crosses only produce a few viable seeds.

In the broad Vanda family (incl. Aerides, Holcoglossum, Renanthera, Rhynchostylis, etc.), intergenerics are moderately easy to produce. Some outliers, such as the Australian Sarcochilus can produce intergenerics, but it is much harder to do (I have tried, but as yet I have never gotten a mature seed pod).

In a different family, I know that:
Phaius tankervillea has produced viable seed when bred with both Calanthe & Cymbidium.
Cymbidium has produced viable seed when bred with Grammatophyllum.
Ansellia africana belongs in this family too, but I don't think it has been bred with any of the other genera mentioned.

[Ray]

Kim, your last statement tantalized me a bit, and I was not aware of any, either, but after a quick Orchidwiz search, it turns out there are a several ansellia intergeneric crosses, made with cymbidium, cyrtorchis, galeandra, promenaea, clowesia, mormodes, eulophia, and cycnoches.

Who knew???

The few that have photos are interesting!

[Fairorchids]

Ray,
Thanks for update (my OrchidWiz died).

I just bought 6 BS Ansellia seedlings from a Southafrican breeder. Once they start blooming for me, I will have to see what Cymbidiuim pollen I have on hand (I love spotted flowers).