Re: HYB: REF: Helen Collingwood descendants

In the older pedigrees from Barry Blyth one will find Opal Brown's 'Pipes of
Pan,' for instance, which is derived from Melodrama--an I(s) bitone, probably
one dose, of Paul Cook's breeding.  I think I remember others of I(s)
involved, some of Melba Hamblen's things like 'Lilac Champagne' which is from
'Mollie Emms" X 'Whole Cloth,' for instance.

It's been over a year since I ran those pedigrees on things I have, like 'Man
About Town' and such.  If I remember what Blyth said in the *Tall Talk*
articles, he turned a corner somewhere along the line, and few of the older
line are included in the present breeding--but some of the older line ( which
included 'Sunset Snows', etc) were carried forward outcrossed to other
materials.

The other side of the same story is that both Ghio and Keppel used varieties
from Blyth in their breeding--thus producing 'Romantic Evening' and Keppel's
red-bearded blacks for example.

'Pipes of Pan' is from similar breeding to what Blyth was doing, involving
Pinnacle, pinks and I(s) bicolors.  It had a problem of passing on rather
narrow falls and some other faults that were the same as in 'Sunset Snows.'

Your speculation that the 'Helen Collingwood' problems would get untangled
over several generations is apt.  Closely associated characteristics--such as
certain faults plus a desirable color--were present in the early pinks.  Poor
form, weak substance, poor and high branching were problems that carried right
along with the recessive Lycopene-displaying pigments.  Over many generations
the problems and the "t" factor separated.

When something like this occurs in breeding it demonstrates that the desirable
character (t) is on the same chromosome, and close to those genes or processes
resulting from enzymes encoded on that chromosome's DNA that are responsible
for the problem characterisics (form, branching, substance).

Cross-overs that separate factors from one another are less and less likely to
occur the more closely factors are on a chromosome.  Factors far apart on the
same chromosome are inherited almost the same as factors on completly separate
chromosome in the genome.  Cross-overs occur between the two on the same
chromosome so frequently the ratios in the seedlings would be hard to
distinguish.

In commercially significant major crops like corn (maize) many factors have
been identified as to which chromosome they are on. The same is true for rice,
humans and the like.  Section by section linkages add up so that a map of the
chromosome for identified one-factor traits can be marked.  Now that DNA
patterning can be done rather easily compared to what was required a few years
ago, the exact sequence of nucleotides can be determnined and related to
specific enzymes or proteins responsible for the identified effect.

Incidentally, sequences on corn, rice, lilies, iris and some dicots are often
the same.  Natural processes are very conservative--there are only so many
ways the porphyrin core of both Heme and Chlorophyl can be constructed.  The
same gene sequences will occur over widely separated species.  Such parallels
says something about the unity of all living organisms.  We all share a common
thread of Life.

One of these days the techniques for splitting a chromosome at a certain point
to separate desirable from undesirable characteristics should be common.  It
can already be done--for a price.  The future of plant and animal breeding
belongs as much to the lab as to the field.  Some extraordinary things are in
our future.

Neil Mogensen  z 7 western NC

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