Brunsvigia self sterility

jim lykos jimlykos@bigpond.com
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 


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