Chromosome doubling with nitrous oxid

A year or so ago I remember someone discussing the use of nitrous oxide for chromosome doubling. The person had built a pressure chamber and was going to try to chromosome double Mermaid or a Mermaid seedling. It could have been a different rose, I dont remember the specifics. I thought it was Jim T

I was wondering if anyone has had any success? Results from experiments?

Jukka mentioned trying doubling with Polstjarnan in a different thread which reminded me of the nitrous oxide thing. I had thought Polstjarnan would have been a good candidate for something like that when I first read about the experiment.

I did that a couple of years ago and wrote an article about it in the RHA Newsletter. I have gotten seedlings using pollen from nitrous oxide treated Mermaid and Baby Mermaid plants. I’ve never gotten any seedlings using pollen from untreated Mermaid and Baby Mermaid plants. I’ve also gotten some hips on my treated Baby Mermaid. I’ve never gotten a hip on the untreated plant.

I didn’t get any seedlings at all this year. A fungus that I’ve never seen before killed all my seeds. The seeds looked like tiny sea urchins with white spikes sticking straight out of them. I guess I planted them in a bad batch of soil. It is so discouraging. I was so excited about the crosses I got last year.

I have gotten a few seedlings from last year’s seeds, including a nice one from the cross Rise ‘n’ Shine X Mermaid. It is a mini with foliage that is much glossier than Rise ‘n’ Shine. In fact, it is just as glossy as Mermaid.

Here is the original thread that discussed nitrous oxide:


Congratulations on your seedlings Jim.

It’s exciting to hear about another source of bracteata genes, especially one that incorporates yellow.