Is anyone familiar with a fertilization technique involving pollinia
from multiple cultivars applied to a single stigma?

The over production of most seed capsules is often wasteful. Each
cross consumes from the plant the full energy necessary to produce a
mature capsule containing many more seeds than are usually required to
judge that single cross. This consumption of plant resources may
influence the breeder to refrain from making additional crosses with
that plant as the pod parent in a given season, thus lengthening the
time required to complete all the crosses in a particular breeding
program.

If, on the other hand, the breeder dissects individual orchid pollinia
from their filaments, and places several on the stigma of the same
flower, wouldn't it facilitate n crosses each consuming only Vigor/n
plant resources? If the intended crosses are each uniquely
intergeneric, recognizing which f1 progeny are members of which cross
shouldn't be too difficult. And all the resources the plant expended
in producing a mature capsule are productively employed in a manyfold
reduction of breeding cycle time.

Does anyone have first hand experience with this technique or pointers
to literature?

I have heard of that being done, with the idea being that you'll get some
plants that have genes from both pollen-parents (A&B) with the pod parent
(Z), or (A+B) x Z. It had nothing to do with the health or vigor of the
plant carrying the capsule.

However, I think Mick is correct. On the assumption that the capsule
"takes" in the first place, the progeny will most likely be A x Z, B x Z, or
some of each and you'll have to wait and sort them out.

I recall correctly (that assumption gets more suspect by the day...), an
ovum can only be fertilized by a single "male" gamete. The instant there is
penetration of the cell wall, chemical changes make fertilization by another
impossible.

--

Ray Barkalow First Rays Orchids
http://www.firstrays.com
Secure Online Ordering & Lots of Free Info!


"Larry Dighera" wrote in message
...


Is anyone familiar with a fertilization technique involving pollinia
from multiple cultivars applied to a single stigma?

The over production of most seed capsules is often wasteful. Each
cross consumes from the plant the full energy necessary to produce a
mature capsule containing many more seeds than are usually required to
judge that single cross. This consumption of plant resources may
influence the breeder to refrain from making additional crosses with
that plant as the pod parent in a given season, thus lengthening the
time required to complete all the crosses in a particular breeding
program.

If, on the other hand, the breeder dissects individual orchid pollinia
from their filaments, and places several on the stigma of the same
flower, wouldn't it facilitate n crosses each consuming only Vigor/n
plant resources? If the intended crosses are each uniquely
intergeneric, recognizing which f1 progeny are members of which cross
shouldn't be too difficult. And all the resources the plant expended
in producing a mature capsule are productively employed in a manyfold
reduction of breeding cycle time.

Does anyone have first hand experience with this technique or pointers
to literature?

On Sat, 22 Mar 2003 07:42:27 -0500, "Ray @ First Rays Orchids"
(Ray @ First Rays Orchids) wrote in Message ID
:

I have heard of that being done, with the idea being that you'll get some
plants that have genes from both pollen-parents (A&B) with the pod parent
(Z), or (A+B) x Z. It had nothing to do with the health or vigor of the
plant carrying the capsule.

It would be interesting to know the results of such an intended
breeding program. The mechanism that would permit genetic material
from three (or more) gamete cells to combine is nonintuitive. Are you
aware of the existence of any literature, that might explain such a
convenient phenomenon? By what means would the chromosomes pair in an
(A+B) x Z cross? Would this chromosome pairing occur as the pollen
tubes descend the column (pistil/style) toward the ovule, or in the
ovule itself? Fascinating.

However, I think Mick is correct. On the assumption that [if] the capsule
"takes" in the first place, the progeny will most likely be A x Z, B x Z,
or some of each

That is what I would intuitively expect.

I would also expect the usual variations of germination-rate/viability
among the individual crosses of a polycross much as would ordinarily
occur if they had happened in separate overies/capsules. I doubt
polycrossing would have any influence on crosses of incompatible
species, aborted crosses, or production of sterile seeds.

and you'll have to wait and sort them out.

Right. That is the downside to polycrossing: the time and resources
necessity to bloom the crosses in order to identify them. However, if
the breeder's initial intent was to grow-out the crosses to facilitate
flower based selection, I see little difference from unicrossing.

[If] I recall correctly (that assumption gets more suspect by the day...), an
ovum can only be fertilized by a single "male" gamete. The instant there is
penetration of the cell wall, chemical changes make fertilization by another
impossible.

That is my understanding also. So, if the information you recall
hearing regarding (A+B) x Z crosses occurring in a single capsule is
correct, the A+B combining must take place during the time the male
gamete genetic material travels the pollen tubes. But that begs the
question of polyploidy.

Thank you for your contributions to the discussion of this topic, Ray.
They are most welcome.

Larry,

If I remember correctly, the crosses published as being of the "(A&B) x Z"
types were paphs sold by Rands (not ray, the folks who took over his
business). I don't know if there was ever any proof that there were any
(A+B) x Z in the progeny, and as I said, I doubt it.

--

Ray Barkalow First Rays Orchids
http://www.firstrays.com
Secure Online Ordering & Lots of Free Info!


"Larry Dighera" wrote in message
news
On Sat, 22 Mar 2003 07:42:27 -0500, "Ray @ First Rays Orchids"
(Ray @ First Rays Orchids) wrote in Message ID
:

I have heard of that being done, with the idea being that you'll get some
plants that have genes from both pollen-parents (A&B) with the pod parent
(Z), or (A+B) x Z. It had nothing to do with the health or vigor of the
plant carrying the capsule.

It would be interesting to know the results of such an intended
breeding program. The mechanism that would permit genetic material
from three (or more) gamete cells to combine is nonintuitive. Are you
aware of the existence of any literature, that might explain such a
convenient phenomenon? By what means would the chromosomes pair in an
(A+B) x Z cross? Would this chromosome pairing occur as the pollen
tubes descend the column (pistil/style) toward the ovule, or in the
ovule itself? Fascinating.

However, I think Mick is correct. On the assumption that [if] the
capsule
"takes" in the first place, the progeny will most likely be A x Z, B x Z,
or some of each

That is what I would intuitively expect.

I would also expect the usual variations of germination-rate/viability
among the individual crosses of a polycross much as would ordinarily
occur if they had happened in separate overies/capsules. I doubt
polycrossing would have any influence on crosses of incompatible
species, aborted crosses, or production of sterile seeds.

and you'll have to wait and sort them out.

Right. That is the downside to polycrossing: the time and resources
necessity to bloom the crosses in order to identify them. However, if
the breeder's initial intent was to grow-out the crosses to facilitate
flower based selection, I see little difference from unicrossing.

[If] I recall correctly (that assumption gets more suspect by the
day...), an
ovum can only be fertilized by a single "male" gamete. The instant there
is
penetration of the cell wall, chemical changes make fertilization by
another
impossible.

That is my understanding also. So, if the information you recall
hearing regarding (A+B) x Z crosses occurring in a single capsule is
correct, the A+B combining must take place during the time the male
gamete genetic material travels the pollen tubes. But that begs the
question of polyploidy.

Thank you for your contributions to the discussion of this topic, Ray.
They are most welcome.