Bill, some tests crosses for that purpose were made here summer 2008.
See archives for photos of some of the seedlings that maiden bloomed
Betty and Chuck and probably others have made test crosses, but because
most of these rebloomers are so climate dependent, it may take growing
some of them for many growing seasons to get reliable data.
I can't yet classify the parents as to theoretical rebloom group in as
much detail as you do, Chuck; so for now, I just call them summer or
fall cycle based on how they perform in my growing conditions.
The test crosses here were among summer bloomers - IMM, MATRIX, RENOWN.
The first two are reliable summers here (if the weather cooperates),
RENOWN has only summer bloomed once.
I also did a few crosses between cousin children from IMM; between sibs
from IMM; between summers and HARVEST OF MEMORIES (because it's so
early, the only cycle that's really reliable here, & I suspect has
different rebloom genetics from the other cycles I grow); between
summers and a non-reblooming very vigorous seedling from PINK FORMAL
known to produce cycle rebloom seedlings.
One, a seedling from RENOWN X HoM, maiden bloomed in Aug, early enough
to qualify as a summer here, then put up two more stalks later. Chuck
has speculated that some seeds may get triggered for rebloom before they
sprout or at least during their winter of germination - these seeds
mostly germinated in Nov/Dec, & while on the sunporch over the winter
would have been exposed to cool temperatures.
Anyway, re: Chuck's comment that the theoretical recessive nature of
summer rebloom hasn't been tested - the tests are being made, but the
results aren't here yet. Unless next year is another drought year, I
should have some results summer of 2010. Betty has posted some of her
results previously, & they seemed to fit Chuck's theories, at least for
summer vs cycle.
Just thought of another test done a couple of years previously - RENOWN
X AUTUMN TWILIGHT. So far, seedlings are very healthy, but somewhat
slow growers, and <no> bloom at all! AT hated the drought years - maybe
2010 will show something.
<Should be so. but it hasn't been tested.
It is also possible that it is a double recessive. So testing needs to
be done. Could be it needs some genes for disconecting daylight trigger
plus genes for disconecting vernalization needs.
Same for Whenever Rebloomers. I do know that Forever Blue X What Again
gave a huge number of rebloomers. But the reversee cross done by Terry
Aitken didn't produce any rebloomers. Could be maternal inheritence of
Forever Blue's plastids and plant vigour is telling factor. I'm
planning on doing reverse cross with good numbers of seeds here to test
in same growing conditions.
Then there is Heterosis (hybrid vigour from specific crosses) which
could play a role