Reinforcement of resistance of modern rose to black spot disease via hybridization with Rosa rugosa

Title: “Reinforcement of resistance of modern rose to black spot disease via hybridization with Rosa rugosa”


I find it difficult to comment on this paper without being snarky. There is nothing new in it that has practical value.

Rosarians have been breeding with the Rugosas since the 19th century. Some gardeners like these varieties, others do not. Rugosa is even tucked away into the ancestry of ‘Margaret McGredy’, as Sam McGredy III and J. H. Nicolas discovered in Sam II’s breeding records.

Part of the problem seems to be that ordinary gardeners tend to be more impressed by novelty than long-term health. Did ‘Crimson Glory’ fall from favor because of its sometime-problem with mildew, or because so very many other deep red roses have come along?

Semeniuk’s spotless roses came and went with little comment. I saw ‘Spotless Gold’ at the San Jose Heritage, but beyond that I don’t know where any of these might be obtained.

Peter Harris discussed the Spotless series in vol 17 issue 3, Fall 1986 of the Rose Hybridizer’s Newsletter.

I introduced a tetraploid rugosa which a number of people used seeds from in their own hybridizing efforts.

Unfortunately, my own limited experience is that resistance to BS in pure rugosa isn’t being carried through to F1 but that may due to the other parent plant that I’ve used. What I’m trying now is to pair up healthy modern tetraploids with species crosses that contain rugosa. Nyveldt’s White, Metis, Ann Endt and Pink Surprise to name a few. I’m hoping that one or more of these species crosses will be the bridge I’m looking for.

I have one Nyveldt’s White x Miracle on the Hudson that has good resistance so far. I’m waiting for it to bloom. There is also a Baby Love x Ruglauca(?) F1 that is immune so far. Ruglauca is (Rugosa #3 × R. glauca) x OP. I’m waiting on this one to bloom as well. This one has smaller rugosa leaves and has smaller stature so far.

This slide group of mainly rugosa hybrids has the parents of the crosses given. Advance by using the right arrow.

I have no objection to Rosa rugosa being used in breeding. I’m all for it. It just bugs me a bit when someone publishes a paper (with WAY too many authors) suggesting that the research is novel. But that’s just me.

You’ve got some nice seedlings there Henry. Is the acicularis you use the rugosa ‘acicularis’ or the species R. acicularis?

I doubled the chromosomes of the Japanese diploid acicularis.

At Morden they crossed Rosa rugosa alba and a tetraploid and got a tetraploid with an unreduced gamete of rugosa. The num is RSM K1 I worked abit
I was not more BS than most garden roses. I believe that it is a physiological resistance and the larger cells somehow affect the plants