Brunsvigia self sterility
jim lykos (Mon, 15 Nov 2010 03:44:45 PST)

Hi Angelo and all

Concerning self sterility in Brunsvigia's - it has become apparent to me
that sterilty/fertility is foremost a direct factor of the Brunsvigia bulbs
reserves and growth vigor. The first two flowerings of B. josephinea in
my garden produced 27 and 31 flowers in subsequent years. However selfings
in both these years failed, with only 3 seeds in the second year which
failed to survive as seedlings. However with the continued growth and
vigor of the B. josephinea bulb into its third year of flowering reached
a peak of 43 flowers.

Attempted hybrids were made between B josephinea and Amaryllis, Amarygia and
Crinum species together with selfings of B. josephinea. With this higher
flower count the Brunsvigia josephinea proved to be self fertile producing
from 2 to 8 seeds from each seed capsule. The intergeneric cross with
Amarygia produced from 4 to 7 seeds per capsule and 0 to 2 seeds for
crosses with Crinums. This latter seed initally grew as Brunsvigia
seedlings.

The following year there were only 22 flowers on the B. josephinea and it
again proved to be almost sterile seed parent to selfings and intergeneric
crosses. Seed fertility was restored in the following year when there were
38 flowers produced in late summer. The other observations related to
flower count is that the number of bulb leaves produced in early autumn is
proportional to the flower count in the following summer.
It was also noted that when intergeneric crosses with Crinums or Amargias
failed, they still produced one or two seeds that looked identical to
Brunsvigia seeds. Occasionally a different coloured seed was produced but
these failed to germinate.
My conclusion was that the Brunsvigia capsules producing one or two seeds
were produced by Apomixis, I tested this out in a subsequent year by using
the pollen of a real outlier Doryanthes exsela a massive Agavaceae from
Australia known as the Gymea lily. I managed to get one to two seeds from
each Brunsvigia flower polinated by Doryanthes - but the seeds were all
Brunsvigia josephinea.

I have tried similar crosses with B. marginata and it behaves like B.
josephinea.

Cheers

Jim Lykos
Blue Mountains Australia