Enhanced & Forced Germination

Walter Moores asked me to elaborate a bit on enhanced and forced germination
techniques.  The details are a bit much to post, but here are the basics.

There are several approaches that form a fairly simple heirarchy.  From the
simple to the complex:

Natural germination.   Standard practice among TB hybridizers -- and what I
recommend for any type of seeds and any climate where it works.  If it works for
you, there's no need to try anything more complex.

Pre-conditioning.  Just a fancy name for storing hydrated seeds in the
refrigerator for a couple of months.  I've used pint-size refrigerator dishes
and moist perlite, covered with breathable plastic wrap.   I've heard that
sandwich bags also work well, as long as they're not airtight.  Then plant when
the reticulata bloom.  Here, that's in February.  

Enhanced germination.  Instead of planting the cold-conditioned seeds, subject
them to a cycle of diurnal conditioning.  Translation:  take the dishes out of
the refrigerator during the day and put them back at night.  After about a week,
some seeds should start to sprout.  When their leaves are 1/2" long, pot the
seedlings and grow them under lights.   The seeds that haven't sprouted after
about 3 weeks of this treatment probably aren't going to without further
treatment.  Your choice is to put them through another complete cycle or proceed
to forced germination procedures.

Forced germination.  Peeling and chipping.  Not for clumsy fingers, poor
eyesight, or the faint of heart.  You get one chance and only one chance to do
it right.  Start with hydrated, cold-conditioned seeds.  Disinfect them.  Peel
away about half of the hull surrounding the hilium end.  With a single-edge
razor blade, slice a paper-thin layer off the end to expose the embryo.  If
you've cut to the proper depth, you can see a small circle a little smaller than
the lead that shows at the end of an unsharpened pencil.  Return to the
refrigerator for about a week.  When the embryos start to elongate, start taking
the dishes out of the refrigerator during the day, returning them at night.
(Don't succumb to the temptation to leave them out at room temperature 24 hours
a day.  They'll grow too fast and become weak and leggy instead of strong and
sturdy. )

Embryo culture.  For seeds from wide crosses that have viable embryos but
insufficient endosperm to support their growth.  For extremely difficult to
germinate seeds, like those of some of the aril species.  WAY beyond the scope
of this discussion, but if you want to know more about it check out John
Holden's articles in the old ASI yearbooks.

Sharon McAllister (73372.1745@compuserve.com)
Still under winter storm watch, but at least they've finally reopened the
interstates.
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index