Looking at pollen(3)

In December 18, 2008 I send two e-mails to Daffnet with the titles ‘Looking at pollen (1)’ and ‘Looking at pollen (2)’. I reported that some daffodils, which should be infertile because of their special chromosome constitution, were found to be pollen-fertile. Meanwhile I discovered during the flowering time 2009 some more fertile daffodils of the same type. One is a cross of Altruist with N. fernandesii (see picture). It should be of the form NNF with two chromosome sets NN of Altruist and one set F of N. fernandesii. Two other pollen- fertile daffodils came from Actaea x N. tazetta. They should be of the type NNT with two chromosome sets NN of Actaea and one T of N. tazetta. I suppose a main part of the pollen is NF in the first  case and NT in the second. Here a possibility exists for crosses of NNF with fertile jonquilla hybrids (NNJJ) to get fertile descendants.  Crosses of NNT with Matador (NNTT)  should produce a family of fertile tazetta hybrids. I made this cross with one Actaea x N. tazetta in this spring, but it is too early to see, if Matador has set seed. Furthermore one daffodil of the cross Pontresina x N. papyraceus has shown pollen fertility. I think that there is the chance to find some fertile daffodils in all crosses of tetraploid standard daffodils (NNNN) with all diploid species (XX). If in these cases (NNX) the pollen is NX, there are many possibilities to breed fertile hybrids. If the daffodils are seed fertile too, the situation is still  better. To proof the seed fertility it is not ‘ the look at the egg cell’, but the longer way to pollinate the flower. I did some crosses of this form three weeks ago, but  the results are not yet to be seen.
 
Theo

2 comments for “Looking at pollen(3)

  1. Dear Theo
    It should be remembered that often in such crosses the resulting plants is fertile because it was pollinated by a (rare) non-reduced pollen resulting in a tetraploid offspring instead of a triploid. Moroever, speaking of N fernandesii, there are  diploid, triploid, tetraploid and hexaploid forms ( often crosses with N gaditanus)!
    Ben Zonneveld

  2. Dear Ben,
     
    I have your article ‘The systematic value of nuclear DNA content for all Species of Narcissus L. (Amarillidaceae)’ always at hand in my notebook. My N. fernandesii is from the Sierra Madrona and should be diploid. If it were the allotetraploid type N. blanchardii Zonn. stat.nov. the descendants of crosses with standard daffodils should be in most cases unfertile like the crosses with the diploid form. Moreover I think my fertile crosses unfortunately are not from the action of a rare non-reduced pollen and therefore not allotetraploid, because in this case one should see 20 to 50 per cent of the pollen sprouting under the microscope and not  about  1 per cent.
     
    With best wishes,
    Theo
     
     

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