(no subject)

Barry Meyers-Rice (barry@as.arizona.edu)
Wed, 27 Oct 93 09:37:56 MST

Hey:

Rah! This morning two stems appeared in my pot of tuberous
Every few days more tubers wake up from dormancy.
_D. menziesii menziesii_. They survived summer dormancy well.
I've finally gotten a good system for keeping these tubers alive
during the summer siesta.

On another note, I have some interesting observations on the US
Gulf Coast _P.pumila_. The flowers of this plant can be purple,
white, or yellow (the latter is called _var.buswelii). It is an
annual or short-lived, and to keep it in my collection I must
insure it produces seed. It doesn't self naturally, so I must do it
(a real bother with this tiny-flowered plant). Well I have grown the
purple-flowered form for about 4 years without incident. About three
years ago I got one plant of _var.buswelii_. Selfing it, I got seed
and this form securely entered my collection. But I have been finding
that these later descendents are sometimes yellow-flowered, but also
sometimes white-flowered! So far the trends seem to be....

Purple-flowered----> purple-flowered
Yellow-flowered----> yellow-flowered + white flowered
White-flowered-----> white flowered

I have not absolutely verified yet that White-flowered plants produce
exclusively white flowered descendents. Nor have I experimented with
crossing Purples with Yellows, etc. Why not? Because this plant is kind
of tough to grow for me, and I usually only have enough seed to keep
it alive from one season to the next---seedling deaths wipe out the vast
majority of the plantlets.

Clearly, if just a single pair of genes control flower colour, then the
yellow flowered gene is dominant (call it Y) and the white recessive
(call it w), so my yellow-flowered plants are YY and Yw, while my
white flowered plants are ww. I do not have enough plants to do any kind
of statistics, so there's no point looking for 3:1 populations. But
this is interesting.

B