Galanthus breeding

[Paul T]

Hmmm... so pollen here would likely only be available early each day, and only the first couple of days at the most after opening, because after that the anthers tend to dry up.  Interesting!!

So Martin..... how do you make certain that your cross is the only pollination the flower has?  Do you isolate them from insects to make sure there isn't any bee pollination (or whatever insect does it in your garden)?

[rob krejzl]

what can be seen when a leaf is cut?

You're looking at the size of the nucleus - the more DNA the bigger the nucleus. With lilies an estimate of the ploidy level can be made by measuring the stomatal cell nuclei under magnification (which doesn't require cutting up the leaves). Saying this, I have seen pictures posted of treated lily bulb scales where the difference between converted and unconverted bulblets, even at an early stage, is obvious.

[johngennard]

Martin,I am relieved that you agree with my appraisal of 'Blaxendales Late' as I have no wish to offend and I agree with you that no one's name should be attatched to any plant without permission from the person concerned.I would go further and say that no snowdrop should bear a new name without the approval of a bonefide examining commitee operating under the auspices of the RHS.There are far too many similar/identical snowdrops appearing with new names and very fancy price-tags fuelled by the hype of the genus by interested parties.
I have myself been collecting snowdrops for 35yrs.and have more than 150varieties/names and I am still adding when I can find and afford varieties that are distinct.I no longer collect 'NAMES'

[Martin Baxendale]

Paul, some snowdrop cultivars produce very little if any pollen, presumably because they're very infertile triploids or infertile hybrids. Those that do produce decent amounts of pollen drop their pollen most freely on warm sunny days, or if the flowers are brought indoors as Mark suggests. I collect pollen (on warm days or from picked flowers brought indoors) by tapping the flower gently with its mouth held just over an open empty matchbox. The pollen will drop into the box (provided there's no strong wind) and can then be picked up on the bristles of a small paintbrush for pollinating.

I don't try to emasculate flowers that I cross as it's far too fiddly on small flowers like snowdrops, I do so many crosses that it'd be impossible anyway, and life's too damn short!    I start pollinating the chosen flowers as soon as they open, or preferably just before they open (by 'popping' the flowers open with my thumb) so that hopefully  I beat any bees etc to the stigma. I keep going back and pollinating the same flowers again and again, to ensure I get them at their most receptive and to load as much pollen on the stigma as possible (essential if using low-fertility pollen from triploids).

The chances of self-pollination are low as most snowdrops seem to not be very self-fertile - although I do think that sometimes 'foreign' pollen from a different snowdrop put onto the stigma might switch off the self-infertility and allow some self-pollination.

Anyway, at this stage I'm not so much trying to breed specific characteristics together as trying to get some tetraploids that will be the basic building blocks of future breeding, allowing me to raise lots of fertile seedling generations and do some 'proper' breeding and selection.

[Martin Baxendale]

Brian, triploid cultivars do, in my experience, make new bulbils after chipping faster (and often larger) than non-triploids, which makes sense as the triploids (and tetraploids) are generally stronger and more vigorous plants than diploids. That's also another useful indicator of the bulb's ploidy level. I usually chip new strong seedlings straight away, so I get a quick indication fromn how strongly they produce bulbils of whether they might be polyploid (though that doesn't tell if they're tetraploid or triploid - I try to guage that by pollinating new seedlings to see if they're fertile) it's all a bit hit and miss.

This polyploid vigour (and the better disease resistance of polyploid bulbs) is also the reason that some very old triploids (like Gal. 'Magnet' and 'S. Arnott') are still around and growing strongly today even though they're really quite aged plants (Magnet, I think without checking, being about 100 years old).

[Paul T]

Martin,

We get quite a lot of "natural" pods on Galanthus here, particularly the unnamed elwesii var monostrictus types.  One of the named ones I was pleased to get seed from was 'Sibbertoft Manor' as it is one of my very fav snowies..... I've lifted teh seedlings to keep the clump "pure" and will await them flwoering in an unspecified number of years!! Who knows how long they'll take to get to flowering size in my non-ideal garden.  The basic monos set seed around themselves at times, particularly some of the locally named ones from Aus (many of which aren't exactly breathtakingly different to other monostrictus  ) and I have osme of them that would be approaching flowering size I think.  Some like 'Warburton' set seed rather freely, and I have little clumps of seedlings in various places about 6 inches out from the clump.  Species like ikariae and reginae-olgae set seed quite heavily here, with or without help (those I HAVE been able to find pollen on, so I have given them help some years).

[Diane Whitehead]

no snowdrop should bear a new name without the approval of a bonefide examining commitee operating under the auspices of the RHS.

I think this happens to some primulas - auriculas, probably - seedlings have to win a prize within a few years in order to be allowed a name.

[David Nicholson]

no snowdrop should bear a new name without the approval of a bonefide examining commitee operating under the auspices of the RHS.

I think this happens to some primulas - auriculas, probably - seedlings have to win a prize within a few years in order to be allowed a name.

It's certainly so, both for Primulas and Auriculas, under the auspices of the National Auricula and Primula Society. The growers of seedlings entered in competition and winning a class are invited to name their plants. This does help to keep down the numbers of poor quality and indifferent plants in the UK but obviously plants come in from Europe and other parts of the world, and nuserymen in the UK are prone to giving plants names with gay abandon.

[Brian Ellis]

Thanks for your enlightening answers Martin.  That is most helpful and I won't feel so bad at not doing very well with some of the twin scaling!  A most interesting subject which I feel I must get to grips with more.

[Gerard Oud]

Martin i noticed you are also trying to find the Holy Grail, if you are going to use oryzaline for the production of tetraploids you have to hurry because its not in production anymore.
Have you tested already some species being multiploid or are you going to do it?
You can do it by examening the breathopenings(correct word?) on the leaves, and compare it with others who are for sure polyploid. I will have some tested this spring, maybe if you have some tested we can do a exchange of information.
By the way using the oryzalin, it take two or three years before you will see the result, and the chance of succes is about 5 %.

[rob krejzl]

Gerard,

Perhaps you could clarify what you mean. Is Oryzalin no longer in production worldwide, or merely withdrawn from sale in the EU? Certainly the place where I buy mine (http://www.phytotechlab.com/Detail.aspx?ID=507) is still offerring it for sale with no apparent warnings about diminishing supplies.

[Gerard Oud]

We heard its out of production here in the EU, because of its licence is running out for herbicide.I think it stays available in Tasmania,we still have for 200 years in stock so there will be no problem for our polyploidirasationprogram.(nice word for scrabble)

[Martin Baxendale]

Gerard, thanks for the warning about Oryzalin being unavailable in the EU. Looks like I'll have to stick to trying the seed route to tetraploids. They took away the snowdrop fungicides too! 

I haven't done any polyploid testing yet, but I expect I will. Can you see the difference in sizes of the leaf stomata (I think that's the right word) with a hand-lense or do you need to use a microscope and special measuring equipment?

The success rate is only 5% with Oryzalin? Does that mean 95% of the bulbils treated are killed and the 5% that survive are likely to be polyploid? Or do most bulbs survive but only 5% turn polyploid?

[rob krejzl]

Withdrawn from use as a herbicide. Quite possibly still available for use as a laboratory reagent then. And given the dilution factor, even a small quantity would last a very long time if you could get hold of it.

Looks like I'll have to stick to trying the seed route to tetraploids

But there are real advantages to converting named forms - you'll have a fair idea of what their properties are for one thing.

The success rate is only 5% with Oryzalin? Does that mean 95% of the bulbils treated are killed and the 5% that survive are likely to be polyploid? Or do most bulbs survive but only 5% turn polyploid?

The Oryzalin is delivered at a sub-lethal dose - most material should survive. Certainly that's the case with lilies where converted and unconverted bulblets are produced side by side on the same bulb scale.

[Martin Baxendale]

don`t you end up with 'Down'snowdrops!

Down's Syndrome in humans is caused by an extra chromosome. Polyploidy is extra complete sets of chromosomes, which is different.

However, if you try breeding with triploids, because of the unequal way the three sets of chromosomes pair and split, you can get seedlings with a chromosome missing, which can lead to unusual aberrations such as new flower forms, which can be very interesting to the breeder and gardener.