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  1. #25

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    Of course it is pollen that is fertile, by fertile ericsmithii it has to have fertile pollen. The two Davey marbled hellebores I have do not produce any pollen.
    Our frosts do not last not very long, flower stalks become limp but stand up when the frost has disappeared. A severe frost will damage flowers and I have had crosses fail if caught soon after pollination..

  2. #26

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    I wonder if through the process of vitro rescue that pollen fertile hybrids will be developed? Hardiness can increase or decrease in this wide cross. You would think with niger involved that they would be hardy?
    Our document would seem to indicate that most sections of hellebore should be inter-fertile. The reason for the rescue would seem to be the carpels. The embryo aborts. I wonder if when we talk of the fertility of the helleborastrum section that allot of the fertility relies on the fertility of H. orientalis. If the cross is difficult, I wonder if you changed the shape of the pollen you would have higher success. You still have the problem of the embryo.

  3. #27

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    Embryo rescue is now commonly used in plant breeding to achieve inter specific crosses across a number of plant species were embryos do not survive to becalm viable plants.
    I am not sue what role pollen shape plays in he embryo development and have not seen any studies to support or rule out this. Mother nature has developed a mechanism to restrict inter species for reasons only known to her.
    Species that have evolved in isolation would be the most incompatible, I recall having a discussion with a retired Canadian botany professor who was trying to overcome the problem by treating the emerging seedlings at the cotyledon stage with a colchicine solution but have lost contact so don't know what success if any he had achieved. Colchicine was used to produce tetraploid orchids an day lilies, similar results can be achieved with other conversion agents such as Orzyln which is available a pre emergent herbicide.

  4. #28

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    Treating seedlings with colchicine or herbicides to induce plody is no doubt being tried and has been tried on hellebore. Normally they treat a daylily fan with an injection or treat seed. It is a dangerous process. I have a number of tetraploid hosta that are fertile but as far as I know there has not been any tetraploid or altered plody in hellebore. Radiation is being tried with results on hellebore but there are no reports of fertility. Generally the tetraploid conversion sterilize or make the converted plant a difficult parent.
    If the vitro rescue produces new hybrids they should produce some fertile hellebore that may be able to be used in the conventional way. Back cross to niger to create a new line that will be fertile.
    I have many species that are reported to be inter-fertile but I only see self sown seedlings that resemble orientalis or torquatus and hellebore that look intermediate between the two. I would think that I would be seeing much more diversity in 15 years in self sown hellebore than what I have seen.
    I suggest that maybe orientalis is the fertility queen. Torquatus and a few others are very fertile with orientalis. When orientalis leaves the picture the cross becomes less probable, that carpel shape and other physical attribute play a role.
    The question that bothers me is the hellebore species inter-fertile but aborts the embryo or is the problem more of conception? I had always thought it was a fertility problem. But now I learn that in allot of cases it is not a fertility problem but a compatibility problem after conception?

  5. #29

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    The best time to inoculate with conversion chemicals is when cell division is occurring and this is something that can easily achieved with TC, surprised it has not been attempted.
    I did play around with treating newly germinated seeds (cotyledon stage) with a dilute solution of Oryzalin main result was dead seedlings, Oryzalin has very low water solubility and co solvents required to achieve dissolution are not plant friendly, given that the chemical is used as a herbicide this is not surprising.
    The inter species issue is now understood to be due a compatibility problem after conception. What s not understood is why?
    When I did try such a cross seed pods formed but then died off. Actually I see the same event with OP of the white double Betty Ranicar, seeds pods form and remain but the pods contain no seed (Mr Dudley cannot explain)

  6. #30

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    Excuse me - I do not understand this discussion: what is the reason for so much effort and, above all, chemistry, if the major part of the species can be crossed in a natural way - so wonderful hybrids are created by natural crosses!
    So what is the reason to force crosses?

  7. #31

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    so we have the discussion about tc here and not in that other thread.
    i donīt know much about chemistry but last year i have read another article which described that the main problem is the dying of the embryo. they worked with a light solution of giberellic acid and got a higher rate of survivors.

  8. #32

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    Because it is a challenge, no other reason. Tetraploid plants are usually larger and with better shaped flowers this would be my focus not on producing inter species hybrids where the incompatibility exists.

  9. #33

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    perhaps it is the fascination of what can be done.
    but you got a point marylou: so much wunderful crosses can be done in a natural way and who the hell needs all those infertile varieties with doubtful longevity such as h. x sahinii winterbells which seems to have inherited the short- livedness of foetidus and is prone to black spot, whereas foetidus produces a lot of seeds and you have to buy that winterbells again. in this sense tc is nothing else than big business (we speak about millions of plants per year) with a certain smell of nestle and monsanto...
    concerning the enrichment of genetic possibilities i believe that it is a dead end street.

  10. #34

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    "concerning the enrichment of genetic possibilities i believe that it is a dead end street."
    So I think too.
    For a healthy creature (whether animal or plant) a large gene pool is necessary. The smaller the gene pool, the more bad (naturally good) characteristics can be inherited. However for a biological fitness an artificially reduced gene pool is not necessarily conducive.
    Nature has a greater imagination and professionalism than we do - even if we do something just because we can, it is doomed to failure in the long run. (This can be seen, for example, very clearly in the pet dog ... and many other pets ...)

  11. #35

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    I was not meaning to suggest that the focus should be either TC or developing interspecies hybrids, my interest is in trying to understand why some interspecies hybrids cannot be achieved without recourse to scientific intervention.

  12. #36

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    I was trying to discuss the fertility of H. orientalis compared to others in the Helleborastrum section.
    Everyone take a deep breath and scratch the title out, rewrite Helleborus and its genetic analysis and possible interspecific hybrids. Now go to page 42. Take page 43 to 126 and shred it. Now remember that H. X hybridus is a interspecific species hybrid. Take a close look at the document. I study this document up to page 42, I am not interested in any other part. This section is a gift. I disregard the rest of the document for once you study the document you find that after three years they successfully grew out less than 150 seedlings. They made selections from this small group. Seems like allot of work for 150 seedlings and very expensive.
    Jeff page 37 is a discussion on postzygotic barriers, page 39 analyses of stored pollen, page 41 and 42 is the data for pollen tube growth that a cross was successful. Page 32 states that the question of ploidy has not been determined. They go on to say that they believe "they are more likely to exist in an amphidiploid rather than an an autotetraploid state".
    I have allot of H. hybridus self seeding and intermediate torquatus hybridus self sown seedlings. I have no other interspecific hybrid occurring in 15 years of having a collection of the Helleborastrum section. I would think I would see more. I have huge pollinating miss in some inter-species cross. The document points to the fact that no in depth studies have been done to verify how inter fertile hellebores are. It is assumed that all Helleborastrum should be inter-fertile. This document and my experience would suggest that H. orientalis and a few other species are very inter fertile while others may not be. I think this document clearly shows what cross will work and what cross will be difficult. I am interested in the easy cross that will create fertility in its children. I am interest in breaking seed dormancy as early as possible to decrease the time to flower. This information is in this document.
    It changes the family tree and verifies the six sections with 22 species.
    I review this document daily and learn something new from it everyday. I do not understand the controversy.

 

 
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