Chipping-induced instability in snowdrops

[annew]

I'd like to get other growers' (and chippers') experiences on instability in snowdrops, most notably (but not exclusively )in inverse poculiforms, or 'iPocs'. Maybe the purchaser of 'Golden Fleece' needs to read this!
These are my observations:
Normal-form snowdrops (examples - Magnet, Bill Bishop) are completely stable when chipped, never showing any variation from the normal form.
Poculiform snowdrops (examples Angelique, The Bride) are completely stable, although I haven't had many of these to try.
Virescent snowdrops ( Greenish, Virescens, and several other unnamed ones I grow) are completely stable, so far.
Green-tipped snowdrops (examples Dreycott Greentip, Scharlockii) are unstable - many losing the green markings on the outer segments. I don't know whether this is permanent. It is my belief that Dreycott Greentip and Scharlockii are very closely related, as DG's spathe regularly splits like Scharlockii, and Scharlockii's spathe occasionally does not split. I have planted out about 50-60 of each variety which had been in baskets, showing a majority of unmarked flowers for several years. As they flower in the open ground, it seems that the majority now are showing the green tips. Spathe splitting is still irregular though. In addition to these two varieties, a green-tipped nivalis from Cliff Curtis and Jessica have also lost the green tips, in Jessica's case every chip except one has no green tips!

[annew]

Inverse poculiform snowdrops (examples Trymmer, South Hayes) show some instability and can completely, and irreversibly, revert to the normal form. Seemingly stable are Corrin, Trymlet and Trym. Definitely unstable are Trymmer, David Baker, and sometimes South Hayes. The original South Hayes that I bought, that turned out to be a normal flower, has not shown any sign of converting back after 7 years.

[annew]

Snowdrops with green ovary, and yellow inner marks (examples Blonde Inge, Lady Elphinstone) can lose the yellow marks, reverting to green. I don't know whether this is permanent.
A whole tray of Blonde Inge is without yellow marks. Lady Elphinstone is a curious case. My original plants used to produce about 5% of flowers with yellow inner marks, even though they have been undisturbed (the usual reason given for reversion) for 15 years. In 2009 I bought 3 new bulbs from a seller on ebay who assured me his came yellow every year. Despite my scepticism, I planted 2 and chipped one. The planted ones have increased and now have about 15 flowers, all yellow-marked. The chipped ones are just opening their first flowers and 1 of the 3 flowers so far is green-marked. Of course I don't know whether the new bulbs were decended from chipped bulbs, or from natural division.
To finally confuse things, one bulb of a seedling of South Hayes which looked similar to the parent last year split naturally into 7 daughter bulbs. I potted them all together, and each one has a different flower this year….

[Maggi Young]

In conversation with an enthusiastic "chipper" last week, she said that she did not think that it affected markings, but that twin-scaling might,  to a degree.

[annew]

I only chip my snowdrops, never twin-scaling. Fortunately daffodils seem to be immune to this kind of variation! 

[annew]

By the way, I'd like to reassure potential customers that I only send out plants which have flowered and been verified correct. I'd advise seeking a similar assurance if buying from any nursery.

[Brian Ellis]

It's really interesting that you are finding that with chipping and not with twin-scaling.  Hopefully someone else with experience will come back to you on this.  You can understand this with twin-scaling as presumably a bit of the genetic material could be missing on a twin-scale, but you would have thought that chips would have been more stable.

[Alan_b]

As I recall, David Quinton had a 'White Hayes' and Jo Hynes tells me she gets an occasional 'White Turbine'.  These are both i.pocs, normally with a central green "stripe" - or no longer in the 'White' version.  Jo had a theory that the white ones might result from bulbils developed from the top of the bulb whilst the normal ones had basal plate - but this was just conjecture.

I have offered-up a number of my novel nivalis i.pocs for chipping, possibly to the same 'enthusiastic chipper' Maggi refers to.  I'll let you know the results, Anne, but I think these are a year or two off.       

[Alan_b]

Oh, and I would have thought your 'South Hayes' are just showing normal variation for small bulbs.  I bet the marks will be different nest year.

[Maggi Young]

By the way, I'd like to reassure potential customers that I only send out plants which have flowered and been verified correct. I'd advise seeking a similar assurance if buying from any nursery.

 I never doubted that Anne -  we'd expect no less from you.

[Mariette]

My Scharlockii are propagating themselves by division and seed like mad, so I never thought of propagating them otherwise. Occasionally one of them has a spathe which doesn´t split, but this feature didn´t prove stable.
My established clumps of ´Blonde Inge´flower sometimes with  yellow mark, sometimes not, sometimes only part of the clump. They´ve been propagated naturally.
A friend told me of a deliberate attempt to produce a white ´South Hayes´by twinscaling, but the results proved instable.
Anyway, to compare, You´ll probably need to grow all in the same soil and allow a few years for establishing. A more experienced twinscaler mentioned, that it may take 2-3 years of flowering for varieties like ´South Hayes´to show their typical features. The expierence of some buyers of such abnormal S.H was, instead, that they simply passed away.

[mark smyth]

Some twinscalers say  there is not enough DNA in the twinscale. This cant be correct. DNA to replicate must be in every cell

[Matt T]

Correct Mark, each cell should contain a copy of the DNA for the parent plant. What could differ is the plasticity of the cells?

Once a cell starts developing down a route to produce a particular type of specialised cell, there will come a point where it cannot go back. Stem cells are highly plastic, they could differentiate into any type of cell - i.e. cells for green petals, pterugiform petals, a leaf, a root etc. I presume that these unspecialised cells are found in the very centre of the basal plate. Some cells, towards the edges of the basal plate perhaps, might be more differentiated - i.e. they have started to specialise to only produce white petal tissue, for example.

Therefore, as a slice from every part of the basal plate a chip should contain cells that can become any/all types of tissue to make an new, identical plant. If you had a twinscale composed of the outermost scales of the bulb/basal plate, you might be missing some cells that are capable of specialising into the tissues you need to make all of the features seen in the parent plant, because there are no stem cells and/or the cells present are on a developmental pathway they cannot turn back from.

Just some musings. I'm not a cell biologist, but do have a background in the biological sciences (ecology, evolution etc)

[Alan_b]

If the result of a twin-scale or chip might indeed be position dependent then the only way we will find out is if the person performing the operation places the chips/twin-scales into separate containers according to where on the bulb the piece came from and then tracks the progress thereafter.  That would be a lot of extra work but an excellent science project.   

[Susan Band]

I tried to propergate the verified Frit. Imperealis by chopping. I got a really wide variety of verigation. I only have a few ov the coloured left Most reverted to green. Somebody with greater knowledge explained what was happening, something to do with the way the DNA was distributed in the cells.