trifluralin (Preem), DMSO, and chromosome doubling

Well, I have Preem,

Where would I get DMSO?

What would be the best way to prepare a solution?

Would it work best to double the chromosomes of

a diploidXdiploid cross (doubling the embryo?)

a diploidXtetraploid cross (i.e. doubling the ovum?)

a tetraploidXdiploid (doubling the pollen?)

Any thoughts, ideas or suggestions welcome.

Chris Mauchline

SE PA, zone 6b

There has been some discussion about this in the forum in the past. For example, here are some threads that mention trifluralin:

and some threads that mention DMSO:

You can buy DMSO at feed stores and some health food stores.

If you are working with seedlings, I suggest a final % trifluralin (active ingredient in Preen, if I remember right Preen is 1.47% trifluralin) of about 0.1% (0.001) and a DMSO concentration of 1 to 2%. I haven’t successfully used trifluralin on axillary buds of mature plants. Since there are lots of leaf primordia over the growing point, it is harder for the chemical to penetrate relative to seedlings and a higher rate may be in order and perhaps cutting the leaf primordia away somewhat before application like Dr. Leo Dionne reported for potato in the 1960’s. I’ve used his technique on potatoes, but haven’t applied it to roses yet. After he cuts the axillary bud he used soaked cotton balls to keep the chemical in contact and in water against the bud. Dr. Dionne breeds roses in Canada and had some nice rose germination articles about a decade ago in the RHA newsletter.