Theo Sanders, Germany

Mentor pollen

August 27, 2018
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Categories: Fertility, Hybridizing

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Crosses of different narcissus species are in most cases successful. If they are crossed with standard daffodils there are more complications. Standard daffodils can be chosen as seed- or pollen parents; nevertheless one gets often no seeds. This behavior can also be observed for the combination of two daffodil hybrids.

In these cases different methods are at hand to overcome the sterility barrier. One of these is to mix so-called mentor pollen, which are fertile with the seed parent, with the incongruous pollen, which shall fertilize the embryo. The mentor pollen can be treated with radiation or by special freezing to hinder a combination with the embryo. This is not necessary if both combinations are interesting for the hybridizer or if the velocity of the pollen shoots of the mentor pollen within the style is smaller than that of the other pollen shoots. Sometimes the mixture of two incongruous pollen types produces fertile descendants (Juotas Proscevicius. Application of Mixed Incongruous Pollen for Interspecific Crosses of Lilies. Floriculture and Ornamental Biotechnology. 2012).

The problem is of general interest for breeders: For example concerning crosses of standard daffodils with bulbocodiums and tetraploid jonquillas. I tried to cross my tetraploid Hawera with standard daffodils without success. Next spring I shall make some tests with pollen mixtures.

My question is: Have other hybridizers tried pollen mixtures for promoting the fertility?

Theo

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3 Responses to Mentor pollen

  1. Brian Duncan, Northern Ireland
    Brian Duncan, Northern Ireland
    August 27, 2018 at 7:24 am

    What an interesting idea Theo. I may try it next season. I knew a gentleman who tried crossing daffodils with snowdrops – without success! Might this idea give even a semblance of a chance?

    Brian

  2. Lawrence Trevanion, Australia
    Lawrence Trevanion, Australia
    August 28, 2018 at 8:34 am

    Hi Theo,

    I am sure it was Steve Vinisky who mentioned years ago the idea of mixing pollen that rarely takes with pollen that is readily accepted – based, if I recall correctly, on lily breeding . I’m sure I tried it, particularly with tetraploid jonquilla, but I can’t give a very informative reply because I don’t database the crosses I make, I only database the crosses that succeed. From memory the strategy did not help at all. And a quick look through my selections of crosses that rarely succeed shows that none were from mixed pollen crosses. This is not strong evidence that the method won’t work, but it suggests one should not be too optimistic. I expect it doesn’t do any harm to try.

     

     

     

  3. Theo Sanders, Germany
    Theo Sanders, Germany
    August 31, 2018 at 12:13 am

    Brian and Lawrence,

    Snowdrops, Leucojum , Pancratium maritimum and Narcissus belong to the same family ‘Amaryllidaceae’. Leucojum Vernum and Pancratium maritimum have the same chromosome number 2n=22 as some tazettas, Snopdrops have a number of 2n=24. In former days I tried to cross Pancratium maritimum with standard daffodils without success. I think the chances for crosses are very low also with pollen mixtures. The chances for these  crosses within the genus ‘Narcissus’ should be a little better.

    Theo