Would species selfing still produce varations in offspring?

[wetfeet101b]

I'm just curious about what would happen if a species orchid is self-pollinated.
1. Would it even produce a fertile pod?
2. Would the offspring still produce variations from the original parent plant?
3. What about two identical species cross-pollinating?

[clintdawley]

1. Yes. It would. Happens all the time in cleistogamous orchids.
2. Yes. The offspring would be varied. When the chromosomes recombine, different traits are expressed.
3. Two identical plants (let's say two divisions of the same plant) would still produce variation.

If you take an Sc. Beaufort 'Elmwood' and do a selfing, none of the "children" would be 'Elmwood'.

[orchid-man]

and to make things more complicated ,so speices will not do a self crossing unless its a different clone

[Jmoney]

as a rule, selfing a species will produce significantly less variability among the offspring than doing an outcross (i.e. between two unrelated examples of the same species). if you were to pollinate among two divisions of the same orchid, in effect it would be a selfing. species sib crosses between two related but non-identical plants of the same species would tend to fall in the middle from a variability standpoint. when it comes to hybrids, selfing will open up the gates for the full range of genetic variability from its ancestry--as an example, the famous Blc. Goldenzelle was created by crossing the yellow-green Fortune by the classic light lavender Horace. the Goldenzelle progeny share fine form from the Horace, but color ranges from the deepest yellow to an deep rich pink.

species selfing is advantageous if you want to have more plants with a desired trait, i.e. albinism. it's also done when there is what we deem a superior flower, although the vast majority of the offspring will not match the standard set by the parent (which can be considered at one end of the spectrum of variability, the end desired by us humans). the major disadvantage, besides homogeneity, is that vigor is often reduced. outcrosses are much better for increasing vigor, and these days you often see poor-growing albino cultivars crossed to more vigorous but normal-colored plants (with the goal of selfing the F1 and getting more vigorous albinos).

[Palito]

one example of an orchid that has a self-pollinating mechanism is Holcoglossum amesianum. The article from Nature is very interesting and it has pictures of the flower:

Pollination: Self-fertilization strategy in an orchid

[Pete]

jmoney's definition was on point. sibling crosses are usually done when a truly superior flower of some sort (shape/color/size) does not present itself amongst the entire grex, or batch of seedlings.. or perhaps when all you have is 2 of said plants. so in which case the 2 most vigorous or best flowered plants will be selected and sibbed.

another example of self pollinating mechanisms is Spathoglottis plicata. the flowers open perfectly for like 2 days and then are closed to make capsules.. its crazy.