The triploid Grand Soleil d’Or generates 2n pollen

Grand Soleil d'Or

I have some Grand Soleil d’Or flowering and found much pollen on the anthers from which about 10 % sprouted. This result is astounding because the plant is triploid and most triploids are infertile. The pollen grains have a medium volume of 45 µmm³. Diploid tazettas have the following pollen volumes:

  • N. tazetta (Figueras)                      19,3 µmm³
  • N. tazetta 1 (Mallorca)                   20,0    “
  • N. tazetta 2 (Mallorca)                   22,9    “
  • Gloriosus                                           22,5    “
  • Tazetta 1, Y-O (Wilf Hall)              20,2    “
  • Tazetta 2, Y-O (Wilf Hall)              29,4    “

Because the pollen volume of Grand Soleil d’Or is about two times that of the diploid tazettas which have haploid pollen with one chromosome set, it is to be supposed that Grand Soleil d’Or has diploid (2n) pollen with two chromosome sets. This offers interesting possibilities for crossing. The combination with tetraploid standard daffodils should yield fertile allotetraploid plants of a type from which today there exist Matador and some Matador OP seedlings only. Perhaps the egg cells of Grand Soleil d’Or are also diploid. In this case selfing would produce tetraploid tazettas. I did this and furthermore made a pollination with Maria Pia.

Theo

3 comments for “The triploid Grand Soleil d’Or generates 2n pollen

  1. Hi Theo,

    Many years ago Marie Parton gave me three Grand Soleil D’Or seedlings. These were from the same pods that gave Quenda and Quokka. The two named seedlings seemed obviously to have paperwhite as a parent and resembled diploids such as Minor Monarch rather than Grand Monarch. The seedlings Marie gave me looked selfed. They were fertile but they were quite small and I took them to be diploid. Unfortunately they rotted. I remember Marie saying something about Grand Sol and a tendency to rot but I can’t remember what it was. I used them as parents of course but only one, crossed with my Bairns Sol, got to the selection stage and it was described as small. It too has gone, so nothing has survived from that line.

    I have done many crosses with triploid tazettas but with not much success and no great results that I can think of.

    Maybe Bill Welch has more optimistic things to say. I lifted 2yo seedlings from his tetraploid tazettas and they are stunning – huge and vigorous, so much so that I’m wondering if I will get flowers from them this season.

  2. Yes Theo, Soleil d’Or egg cells appear to commonly be diploid also.  I have numerous tetraploids, highly fertile, from crossing my tetraploid conversion of Australian Paper White onto it.  And Graham Phillips got ‘Sol City’ (fertile, likely tetraploid) from Soleil d’Or x Malvern City. It needs warm temperatures 70 F or above to cross and, like other triploid tazettas, repeat pollinations for at least 3 days makes a big difference in seed set!

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