Digest Number 442
From: Sharon McAllister <73372.1745@compuserve.com>
Message text written by Jeff Walters:
>
I would think the probability of getting a tetraploid seedling from a cross
of two diploid parents would be vanishingly small. Perhaps Sharon
McAllister might have some insights here.
<
I prefer "extremely remote" to "vanishingly small".
I believe that Simonet found one probable example in his quest for
tetraploid breakthroughs [I don't recall the name and that's more digging
than I'm prepared to do in the wee hours of this morning] and Mitra
theorized that the tetraploid form of I. kashmiriana arose spontaneously
from the diploid form. Some of the articles I encountered early in my
hybridizing career were in journals of plant genetics, where quite a bit of
work had been done in the production of amphidiploids by crossing otherwise
incompatible diploids. IF you accept the definition of amphidiploids as a
special type of tetraploid I suppose that would serve as an example of the
utility of diploids in quest of tetraploids.
But, overall -- let's just say it's not something we count on!
Sharon McAllister
73372l1745@compuserve.com
<
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