Early results from cross-breeding Les Hannibal's Amaryllis

Michael Mace mikemace@att.net
Sun, 12 Sep 2010 23:08:28 PDT
I'm finally getting flowers from some crosses I made of Amaryllis hybrids
from Les Hannibal.  The results are puzzling, and I'd love to get
suggestions or words of wisdom from the Amaryllis and plant breeding experts
on the list.

Quick background for people who joined the list recently:  About 10 years
ago, the late Les Hannibal permitted a number of us to dig Amaryllis bulbs
from his backyard.  These were the extras from decades of breeding he had
done -- he threw surplus seeds down the hill and let them grow anywhere.  I
ended up with about 50 bulbs, a mix of whites, light pinks, dark pinks, etc.
You can see pictures of some of them here:
http://pacificbulbsociety.org/pbswiki/index.php/… (you'll need
to scroll down a bit)

I am not a professional plant breeder, but I wanted to see if I could make
some improved forms from the bulbs Mr. Hannibal gave me: match the superior
size of one plant with the color of another, stuff like that.  So I started
making crosses.  Now 10 years later, the first of those crosses are finally

I am trying to figure out what controls flower color in these plants, based
on the limited knowledge of genetics I got from taking a couple of bio
courses in college.  In other words, I am a rank amateur, and I'm getting
really confused because the flowers don't appear to be acting the way the
textbooks say they should.

Here's what I am seeing:

1. Crossing a pink flower and a white flower generally produces a majority
of pink flowers and a minority of white flowers.  I don't have enough
blooming bulbs to have a statistically accurate sample yet, but so far it
looks like the ratio is about 3:1 or 4:1 pink to white.

2. Crossing a mid-pink flower with a dark pink flower produces mostly pink
flowers that are intermediate in color between the two parents, plus a
minority of white flowers.  Again, the ratio might be about 3:1 or 4:1 pink
to white.

3. In one case, crossing a dark pink flower with a white flower produced all
white seedlings.  This is especially weird because the pink flower was the
seed parent, so these can't be apomixic seeds (clones of the seed parent).
Unless of course I screwed up my notes and switched the seed and pollen
parent.  But I was pretty careful.

Anyway, here's what I think the results are telling me:

--The ratio of pink to white flowers implies that pink color is dominant
over white color.

--However, I don't know what to make of the fact that the pink shades
average out when they're crossed, rather than one being dominant over the
other.  What is this telling me?

--The fact that I got some whites by crossing two pinks implies that both of
those pinks had recessive genes for white, right?  Since one of the pinks I
crossed was my darkest pink, I don't know whether any of my bulbs have pure
pink color genes in them.

--I can't figure out how a cross of a pink and white flower would produce
all white flowers, unless in this case white is dominant.  But could a gene
be recessive in some cases and dominant in others?

I'm really confused.  Would any of the experts out there care to comment?
Any advice?  And can anyone recommend a good book or website on plant
breeding and genetics that might help me figure out what I'm seeing?


San Jose, CA

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