HYB: Pollen Daubing (Mentor Pollen)
John Montgomery wrote:
> The theory which seems to be held by most practitioners, is that the f=
> grains of compatible pollen will overcome any chemical barriers to
> "strange" pollen and open the floodgates as it were.
That's a good analogy. I don't
know the physical explanation,
perhaps the alcohol bath ruptures
the pollen grain and exposes the
protein that's key to triggering the
chemical response. But the
advice passed down by iris hybridizers
has stressed killing the pollen first.
Both physical and chemical processes
seem to be in play in terms of the
receptivity of the stigmatic lip -- but
I believe that only physical factors =
affect the end of the receptive period, =
because it can be prolonged by smearing the =
drying lip with juice obtained from the
stigmatic lip of another flower. Any flower,
not just one of the same cultivar.
> I do not know whether this would work in iris breeding.
I think it's worth a try, although =
evaluating seedlings from mixed
pollen is a significant challenge.
I'd certainly recommend using only
a few grains of mentor pollen with
the usual amount of pollen from the =
desired parent, because certation =
significantly favors the mentor. =
Technical aside: Certation is the =
differential growth rate of different
genetic types of pollen or pollen
tubes, in a given environment. =
Growth rates are not absolute, but
rather depend on the compatibility
of the two types.
> If the theory is
> correct, it would seem to me that it would not be superceded by embryo=
> culture. If the barrier is a chemical one, you would have to overcome
> before any seeds were produced.
No. Seeds from wide crosses, =
however they were obtained, often
have defective endosperm and must
be given some special treatment.
The FIRST hurdle is getting the seeds.
The SECOND one is getting them to
The THIRD one is growing the seedlings
to bloom size.
The FOURTH is finding survivors with
But it's all worth it when that breakthrough
I would really be interested in the opinions of those who are more up to
date in bootany than I am.
Vernon BC Zone 5