Sunday, May 9, 2010

How tiny does tiny get??

It is a fairly well documented fact (R. S. Moore and others) that the miniaturism trait is a dominant one, and you need only one of the parents to be a miniature in order to obtain a good percentage of dwarf plants from a cross. Well, what happens if you cross miniature X miniature? Often, the offspring get smaller still! If you have ever done a cross like that, you will have no difficulty imagining how Pedro Dot came up with 'Si'.

Illustrated here is one of the first seedlings to bloom from a crop of 'Magic Wand' X self seeds. Out of about 80 seedlings I have grown, I would say that about 90% are dwarf, with about 25% of these being extremely dwarf. About eight or ten seedlings appear to be much larger in both leaf and growth habit than the parent variety, which is also to be expected with such crosses.

To give you an idea of scale (yes, I ought to have photographed it with a coin beside it) the pot shown here is 2.75" square. The plant is currently no more than 1.5" tall, and I would estimate that bud is no more than 1/8th of an inch tall (center of the plant, pale pink): the ultimate in cute. Click on the photo to get a much larger image.

I didn't grow this group of seedlings with the idea of actually keeping any of the offspring, I did it to show me the scope of what 'Magic Wand' would do as a parent. If it harbors extremely undesirable traits, they will show up in a selfing batch. Desirable traits as well, will manifest in the seedlings, and so this is a learning excercise more than anything. I often sow self-seedlings from a variety before I put it into actual use as a breeder, just to determine its fertility and other traits. Mind you, I am pretty certain that I will save a few of the best of these tiny things and keep them around as curiosities. ;-) I'll post photos of some of the others as they flower, assuming they are the least bit photogenic!


  1. I think it is the epitomy of exquiste! I also love how, even as a very young seedling, it seems to have a lovely, compact, vigorous, growth. It is my favourite rose colour!

    So, would you say this extreme miniaturism is a bad trait to be culled or a good one? I was thinking of using some of the smaller minis I have here in an attempt to tame more quickly such giants as gigantea, longicuspis, and bracteata. I have an unknown mini with tiny clusters of flowers that looks like 'Popcorn', however, the whole plant is not more than 20cm tall, the leaves barely 1cm long, and the flowers are not more than 2cm across ('Snow Carpet' might also be a good choice for this, hmmm). I am assuming it is diploid due to its diminutive stature. It produces boat-loads of pollen so was thinking it might be useful for this purpose???

    The thinking being that the over abundance of dwarfing polygenes (because this is what I think it is... other genes 'working' in conjunction with dwarfing genes to modulate the expression of the gene. I guess homozygosity is also a big factor), would balance out and temper traits such as internode lengthening and foliage size. 'Magic Wand' is diploid too isn't it? I think this also exacerbates the miniaturism.

    If you ever get sick of this one let me know and we'll line up to have it placed in a crate of coffee grounds and smuggled into the country ok ;)

  2. "So, would you say this extreme miniaturism is a bad trait to be culled or a good one?"

    Well, Simon, I would say that depends on what you want to have happen. I believe miniatures can be very useful to "tame" larger species. If at all possible, make an effort to match ploidies in order to help maintain fertility, since odds are you will need to proceed at least one more generation before you have results you want. (And yes, as far as I know 'Magic Wand' is a diploid; its pedigree certainly suggests it) I have about 15 seedlings of a cross of R. bracteata X 'Magic Wand' this year, which, although developing painfully slowly, will hopefully provide a new race of Bracteatas that remain diploid and might prove useful in taking that kind of breeding in a new direction. Time will tell!

    If you want some open pollinated seeds from 'Magic Wand' at the end of the growing season, I will gladly send you some. It possesses exceptional Blackspot resistance (immunity?) in my garden, which is remarkable, really. I am hoping this characteristic won't be lost in breeding, if I select carefully.

    Your "Not Popcorn" sounds intriguing. I would definitely use whatever you have for breeding if its traits fit in with your plans. Just because you don't know its true identity doesn't mean it might not be extremely valuable in your work! Good luck.

  3. G'Day Paul :) That would be awesome! It's such a shame that we can't exchange material more freely... It's a very one-way street :( I'll blog some pics of my 'Not Popcorn' to show you what I mean.

  4. So how often would you say that you find something good with self pollinated seedlings. Is it very rare or does it happen enough that you are not shocked by it.

  5. I get a few decent seedlings almost every time I grow a batch of "selfs". I would define "decent" as something curious enough to save, even if only for a single interesting trait. In the case of this group of self of 'Magic Wand', I can tell already that I will likely keep 6 or 8 to grow on, solely for their extreme miniaturism. A year from now I will likely whittle it down to one or two of the better ones. Bear in mind that I am not keeping these as potentially commercial varieties (One 'Si' in the marketplace is plenty, IMO), I save them only for my own amusement. Occasionally I will save a plant for testing as a breeder if something totally unlike its siblings turns up. For example, right now in this group of about 200 seedlings, there are three that are showing foliage and growth that is far larger than 'Magic Wand', and so I will watch these and see if they have any other interesting (and of parent potential) qualities as they mature. Selfings are largely a tool for showing me:
    1) whether the variety produces easily germinated seeds
    2) what traits, both dominants and recessives, are available in that rose
    3) whether or not that plant appears to have ANY potential at all as a breeder.

  6. Paul, I was just looking at 'Magic Wand' on HMF (your whole plant photo is amazing) when I noticed one of the photos, by Margaret, is at Ruston's here in Australia.... so I'm on a mission now to see if it can be found... will let you know how I go.

    P.S. Don't forget number 4! To bring out recessives without losing ground ;)

  7. Hi Paul,
    Are you planning to show the rose again after the bloom opens?
    James Scurlock

  8. Thank you for the pictures Paul. Always interested in seeing different sides of Magic Wand.
    Andrew Grover

  9. Jack,
    That photo will be coming later today, yes. I will also include at least one of its siblings as well.

    Andrew, thanks!