Self and Sib Crosses and their Hybrids

[psoque]

Having a PhD in one of the biological sciences, I think I have a good understanding about the actual genetics of living things, but the whole business of orchid hybrid nomenclature is something else, and here's my question:

I see that self- or sib- crosses of hybrids are typically noted as "x self" and "x sib." That part is simple. However, how do we keep track of the self/sib crossing when a "x self" or "x sib" is crossed with another plant to create a hybrid?

For example, if the name of the hybrid orchid A crossed with hybrid orchid B is already named hybrid orchid C, it is the case that hybrid orchid A x self (or x sib) crossed with hybrid orchid B an also be named hybrid orchid C?

Or are we discouraged to use self/sib crossed plants for crossings, to keep us from having this conundrum?

Furthermore, when a known crossing (crossing that already been named) results in 4N plants, do we still call that hybrid with the same name? How about the crosses of the 4N plants???

Also, for that matter, does the nomenclature system really distinguish between a division/mericlone vs. self/sibling/4N crosses?

Or do I have too much time on my hands???

[SouthPark]

Book keeping can be an issue.

I think that the focus is mainly on the cross ..... aka grex. Or grex name. The marketers and breeder/seller is usually the one that focuses on the particular cultivar.

The whole thing is a juggling act ----- so to keep everything simple, the registration department mainly wants to know what the cross is ..... the grex.

The rest is up to book-keeping (ie. the growers do some book keeping). Fine details in history (ie. selfings and sibling crosses etc) can easily be lost with time. But ----- if people try to just get the correct grex, then that should be nice.

Even when a particular plant from a cross undergoes mutation, they typically still classify it under the same grex. Not sure what the rules are here ...... as my understanding of DNA isn't fantastic. Eg...... what extent of mutation of a hybrid before a plant is not classified under the same grex.

I have heard people say that a mutation of a hybrid can/could/is be equivalent to one of the results of sibling cross and/or self-cross. So at least the same grex name is retained.

And if somebody encounters a particular cultivar from that cross that might deserve some additional name for recognition, then that's when you can add a cultivar name.

For scientific research and/or breeding, accurate book-keeping can be important. But that relies on making sure that all the details about the samples are accurate, and maybe retained. But also need to consider that results generally can't be replicated - due to all the DNA related aspects. Eg. the likelihood of somebody being able to reproduce a cultivar (using independent crossing attempts) is negligible........ chance is very unlikely.

But keeping records can be beneficial to at least the breeder or from a scientific perspective.

[Ray]

The classification system was developed before there was scientific knowledge of genetics.

"A", whether 2n, 4n, sib, or self, when crossed with "B", whether 2n, 4n, sib, or self, will always be "C", and it holds true whether the hybrid is "A" x "B" or "B" x "A".

As to the mutation being classified differently, I think that is handled well by the varietal tag. An albino human is still Homo sapiens, after all.

[Fairorchids]

All species produced from seed are originally either 'x self', or 'x sib'. To taxonomists, it doesn't matter, such plants are still the basic species.

When we cross A x B (or B x A), we create a hybrid = C. The RHS doesn't care which way we did it.

The distinction of 'x self' or 'x sib' is only of interest when we are dealing with special varieties, and we are trying to improve on the species in a line breeding program. In this scenario, we want to know what the genetic make-up of the individual plant is.

Going back to hybrids, here these distinctions are not used. Only clonal names, which identify specific plants.