RE: re: HYB: Identifying pink carriers

Linda,

It has been my experience that there is no visibile difference in most if not
nearly all cases of levels of "t" short of all four.  In any cross involving a
parent of unknown "t" dosage X visibly expressed "t" (tttt), none of the
seedlings are not carriers.  All will breed at least one out of six expressed
"t" if crossed with a tttt clone....provided the crosses are both true and the
understood genetics of carotene/lycopene conversion is both correct and
working.  The genetics of tetraploids, however, can have some very strange
quirks from time to time due to how pairing occurs and how cross-overs split
the parental contributions.

What gets complicated is when the cross is between two carriers, neither of
which is fully tttt, i.e., not having a tangerine beard, however expressed.
The ratios can be rather complicated.

Also, be mindful that not all "tttt" tangerine bearded sorts have very "red"
beards.  Some of them have beards with yellow-orange, orange or even brownish
to chocolate colors--the latter if a little blue is present.  It is easiest to
tell by checking the pedigree (if you trust it....) to see if both parents are
tttt--tangerine bearded to whatever degree.  Part of the reason for this seems
to be that not all carotenes are converted to lycopene, or may be converted
less than fully.  There may  also be xanthophyll pigments present in TBs--they
don't convert to lycopene at all, being from another chemical family
entirely.

Wouldn't it be wonderful if we could "zap" the "t" gene and turn it into the
tomato gene "R," which is a carotene-to-lycopene conversion factor, but also a
strong dominant.  Even better, the lycopene gets stronger and redder, instead
of weaker and more dilute as in irises.  Just compare the color intensity of
yellow tomatoes to red ones!

Neil Mogensen  z 6b/7a near Asheville/Hendersonville, NC

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