ABBB - AABB Crosses
Updated:
ABBB - AABB Crosses
Updated: 20 April, 2007
Returning? Jump to Photos This page presents "quarterbred" seedlings obtained by the
"3/8ths-Route", crossing ABBB-type tetraploids with AABB-type amphidiploids.
These have the potential for producing offspring of two genetically
different types and this must be taken into account in evaluating their
seedlings. Tell me more about the
nomenclature.... A cross between an an ABBB-type tetraploid and AABB-type
amphidiploid can produce both AABB-types (functional halfbreds) and ABBB-types
(functional quarterbreds). If you are tempted by these types of crosses (and I
certainly am!) you should be aware that many of the progeny will be very
difficult to classify within the current criteria.
Theoretically, a set of such seedlings should segregate neatly into
two groups -- but real life is a bit more complicated. In practice, I
have found that:
Many will look like and breed like halfbreds (OB, RB, or OGB).
Many will look like and breed like quarterbreds (OB-, RB-, or OGB-).
Some will look more like halfbreds but breed more like quarterbreds.
Some will look more like quarterbreds but breed more like halfbreds.
Some will be intermediate in both appearance and breeding behavior.
Although the first two groups are relatively easy
to classify, the others provide a significant challenge and the present classification
system effectively precludes introduction of those with intermediate traits. Click
on the thumbnail to see a larger version of a photo.
89-12: Casa Vicente X Joint Venture. One of those ironic
cases in which the three best seedlings happened to be lined out adjacently in
their first seedling bed. Go to Sibling Sheet for more
details.
Hybridizing
Terminology. You won't find these terms in official classification
systems, but will see them in articles written by such well-known
hybridizers as Tom Wilkes and John Holden. "A" simply stands
for a set of aril chromosomes and "B" for a set of non-aril chromosomes. Fractions
were sometimes used to depict the number of sets of
aril chromosomes and the total number of sets. An AAB-type triploid
might thus be called a "2/3-bred", while "2/4" would
indicate a halfbred with two sets of aril chromosomes and two sets
of non-aril chromosomes, and "1/2" would stand for a diploid with one set of
aril chromosomes and one set of non-aril chromosomes. These
terms were once widely used by hybridizers, but fell out of favor after the
Aril Society adopted the Modified Chromosome-set Classification System but retained
the nomenclature from the older Quantum System. Today, "1/2"
usually means a fully fertile halfbred with two sets of aril and two sets of
non-aril chromosomes. I have used the old-style
hybridizers' terminology here, because it is not possible to accurately
determine the correct classification code for seedlings of this type without
extensive test crosses.
The first section dates to the period in which I numbered crosses when I
lined out the seedlings and seedlings when they were selected to save for
further evaluation and possible introduction. The numbers are therefore no
indication of the number of crosses made or the number of seedlings produced by
each cross.
88-5P: Mohric Art X Heavenly Sunlight. MOHRIC ART is itself from "3/8ths" breeding. Is it a
quarterbred or halfbred? At one time, I believed that its relative
fertility was evidence that it is a halfbred but from the performance of its
offspring I now believe that it is more likely a quarterbred. Go to Sibling Sheet for more
details.
88-5P-1 Introduced as WANNABEE, classifed as an OGB- because of its
lack of interest in parenthood.
88-5P-3 In spite of its stunning appearance, this one has spent years in limbo because it
looks like a halfbred but breeds more like a quarterbred.
89-12-6 Introduced as DON'T BE SHY
89-12-7 Introduced as SIMPLY LUSCIOUS
89-12-8 Introduced as AT LAST.
90-11: Mohric Art X Boaz.
#90-11-3 Introduced as MOHRIC BUTTERFLY
