MTB's

Jon Cliburn,
In response to your inquiry concerning time of day to hybridize: 
Crosses made in the morning hours seem to be the most likely to succeed.
The reason for this is the fact that the stigma upon which we place the
pollen is moist and therefore receptive to the pollen. As the day warms
up the stigmas begins to dry out and by late afternoon the prospect of
setting seed is greatly dimished. Of course, in cooler weather this is
not such a major factor. We have found that in hot weather it is better
to gather your pollen the afternoon before, place it in an envelope or
film canister (or whatever) and use the pollen the next morning. Be sure
you label the envelope et. al so you know what you have. Keep a written
record of all crosses. Make a note if you succeeded or failed.  As some
iris are just not fertile and/or we have learned that some will set seed
under certain climate/soil conditions and some won't. The diploid iris
seem to be more 'finicky',if I may use an old fashioned term, than the
tetraploids. They also seem to be more receptive to the bees than to
humans. I wonder if we have something to learn? :-)
     Another thought... if you wait until the afternoon to try your
crosses you may be trying to polinate a flower that has already been
polinated by the an insect.
     Usually crosses will not set if it is raining. This is due to the
fact that if pollen gets wet it looses its viability. 
     If you are trying to cross diploid MTB's to SDB's or mixed
chromosome IB's, you probably won't have much success as the chromosmes
are unable to pair up.  Some success might be had with TB's or 48 C
tetraploids. Our modern day tetraploid TB'S are believed to have come
about from the doubling of the diploid (24 chromosome). 
     I hope I have been of some help to you. Good luck! 

Vicki Craig cragiris@ipinc.net
Tigard, Or
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