Backcross

[bullsie]

I hear more regarding backcrossing in Paphs than any other hybrids made. Do backcrosses tend to be as similar to the original crossings made? Any pros or cons?

Thanks!

susan

 

[NYEric]

Some Paphs are fairly quick to give progeny so people do a lot of crosssing. If you know what the parents are like you can make a fair guess at the children.

 

[goldenrose]

No easy answer to that one, really depends on the parents that are being used.
Let's take a primary cross, I'll use Mem. Violet May as an example -
Mem. Violet May = fowliei x godefroyae, 2 very different species.
A backcross would mean your taking Mem. Violet May and crossing it with fowliei or godefroyae. If you use fowliei than one should get more fowliei characteristics, if you use godefroyae than the opposite would be expected.
If we use a complex as an example - Lucky Bells -
Lucky Bells = Bella Lucia x bellatulum. If I crossed Lucky Bells back to bellatulum, then it could be very similar as Bella Lucia already has bellatulum.
If I cross Lucky Bells back to Bella Lucia, then I still have quite a bit of bellatulum.
The pros, as Eric mentioned, would be if you know your parents, then it's easier to predict the outcome.
The cons are if you don't know the parents & their ability as breeders - it's wait & see!

 

[likespaphs]

also, pod parent vs pollen parent matters

 

[Ross]

A back cross can also be done to "bring out" desirable recessive characteristics.

 

[bullsie]

also, pod parent vs pollen parent matters

Does that mean if Lucky Bells registered as Belle Lucia x bellatulum were reversed bellatulum x Belle Lucia would result in different atributes of the offspring? Pod parent and pollen parent reversed?

 

[Brian Monk]

Maybe. The tendencies that pod parents offer are growing habit and vigor, plant size, temperature tolerance, and just about anything that deals with how a plant grows. IME, flowers tend to be less affected by the difference in pod/pollen parent, except maybe for yellow color (at least in Cattleyas and Oncidiinae).

Backcrossing should not be done randomly. It is done to bring out specific traits present in both parents, or SHOULD be present in the genome of one of the parents based on your knowledge of what the parents do. For example, your primary cross Mem. Violet May produces some very pretty pastels, but on relatively poor stems. You want better stems, so you cross this back to fowliei to get them. Or you want rounder flowers, so you put it back onto godfroyae.

BUT REMEMBER INDEPENDANT ASSORTMENT of the chromosomes. It is not just a good idea, it's the law. Randomness plays a huge role in these crosses. Growing out a bunch of seedlings gives one the opportunity to see not only if anything good turns out, but what traits are dominant, what is bad, what is good, and is it consistent. Given the inescapable fact that Paphs cannot be clone, this idea of a clone that throws good offspring becomes tremendously important (especially to the pot plant industry). You know that every plant (or at least most of them) will have the traits you are looking for. That makes some clones exceptionally valuable. For example, C. Horace 'Maxima' breeds for size and shape, and is recessive for color. But half of the offspring will have cripled flowers. At least you know that before you use it.

 

[Eric Muehlbauer]

Back crossing is also done to improve species characteristics. For example, a good Paph. callosum has gorgeous downswept petals and a wide, round dorsal. Except that dorsal tends to curl asymmetrically. So you can cross it with lawrencianum to make Maudiae, with a flatter dorsal...OK, but now the petals are more horizontal. To restore the downswept petals and keep the huge round (and now flattened) dorsal, Maudiae can be crossed back to callosum to make Holdenii....and if that doesn't satisfy you, cross it back again to callosum to make Gloriosum. By this point, its just going to look like callosum. But, if a breeder, who may get lots and lots of plants, can select those few that look like perfect callosums with flat dorsals, he/she has some winners!

 

[bullsie]

WOW! Love this conversation. I've never bothered with the breeding end of orchids. Very unique. Thanks all for the great info.