recent research paper: Rosa rugosa X Rosa hybrida interspecific cultivars.

Rose Genetics Ancestral Roses
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Title: Diversity in Rosa rugosa Rosa hybrida interspecific cultivars.

Authors: Sparinska, A.; Zarina, R.; Rostoks, N.

Authors affiliation: Botanical Garden, University of Latvia, Riga, Latvia.

Published in: Acta Horticulturae (2009), 836(Proceedings of the XXIIIrd International Eucarpia Symposium Section Ornamentals: Colourful Breeding and Genetics, 2009), pages 111-116.

Abstract: “Modern roses represent a relatively narrow gene pool resulting in poor disease and abiotic stress resistance. The diploid species Rosa rugosa Thunb. shows high disease resistance and tolerance to environmental stress conditions. However, their ornamental characteristics are in need of improvement. Interspecific crosses between Rosa hybrida and Rosa rugosa are difficult to obtain, but they could potentially yield resistant varieties with valuable ornamental properties. Eight Latvian varieties that resulted from crosses with R. rugosa type roses and six parents were analyzed with 21 microsatellite markers to confirm the results of interspecific crosses and to identify presence of modern rose genetic material. According to preliminary data, the majority of varieties that resulted from interspecific crosses showed strong presence of R. rugosa gene pool both in terms of genotype and phenotype. However, two crosses, ‘Abelzieds’ (R. rugosa ‘Alba’ ‘Poulsen’s Pink’) and ‘Zaiga’ (R. rugosa ‘Plena’ ‘Flammentanz’), exhibited presence of Floribunda and Climbing rose characteristics. Phenotypically, only one interspecific cultivar, ‘Zaiga’, showed modern garden rose type flower color and leaf shape. Nevertheless, both ‘Abelzieds’ and ‘Zaiga’ could be used for breeding owing to good disease resistance, rigorous growth, and ornamental characteristics.”

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Henry:

Reading this abstract and Don Holeman’s article in the RHA newsletter, is there an implication that maybe the rose needs to be “reinvented” or at least redirected in some way? Let’s say a post-modern rose? We are, after all, working with about 150 years of the “modern rose.”

I see a number of folks here that use species and older roses. Is this an attempt to hybridize (not simply breed)something entirely new? Maybe a rose that looks like a tulip, daisy or whatever? That’s not intended to be a flippant question. Who would have believed in 1800 that we would have modern HT’s, varieties of mini’s, stripes, etc?

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Jeff said,

“Is this an attempt to hybridize (not simply breed)something entirely new?”

The short is answer is, absolutely. For instance see link for a photo taken earlier today.

The problem will likely be educating the public in hope they will accept something new.

Most of us are working on integrating species into the current genome. There’s certainly room for any type of experimentation.

So far there’s no way to get around working with China derivatives for introducing true repeat that I’m aware of.

Link: www.helpmefind.com/plant/l.php?l=21.130397

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Jeff

I would like to hybridize roses with hemispherical plant nice foliage and a spectacular naturally well groomed flower display just as i.e. peonies or camelias.

Just as Austin needed modern roses to be added to OGRs they will be difficult to bypass.

However I do not think integrating species to current genome is enough. It is a mainstay of rose breeding history and modern roses display this strategy limitations. At least in some seasons or climates.

There is a strong necessity to introduce much more genetic and aesthetic diversity in garden roses. As it is more or less achieved concerning Ground Cover roses that are innovative.

Robert, you said:

“So far there’s no way to get around working with China derivatives for introducing true repeat that I’m aware of.”

I agree only if you define true repeat as the China’s one.

Could you elaborate as you know there are some repeating species.

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Jeff asked

is there an implication that maybe the rose needs to be “reinvented” or at least redirected in some way?

Only if you want something new and different. With the current gene pool being remixed at an accelerating rate (currently in the low-millions of times per year) it is clear that we have reached the limit of diminishing returns.

Robert said

So far there’s no way to get around working with China derivatives for introducing true repeat

I would go farther and say that the best place to start is with modern roses.

It took nearly a century for true remontancy to become fixed into the genome of modern roses, the starting point being the cross of R. moschata with R. chinensis. It appears that it was the cross that gave rise to remontancy, neither species parent being especially remontant in their own right. This was followed by many generations of back-crossing to finally yield fully remontant roses. It took another century to blend that characteristic with other desirable traits.

With a few exceptions (the miniatures from Ralph Moore, the hulthemias from Alex Cocker and Jack Harkness and the hardy roses from Wilhelm Kordes), efforts in the 20th century focused on amplifying existing traits rather than introducing new ones.

The roadmaps given by the major descendencies show us not only where we have been but where the forks in the road are - paths that could have been taken. Many of the roses in these descendencies (and their siblings) still exist and could serve as points of departure in new directions.

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What stood out most for me was this:

“According to preliminary data, the majority of varieties that resulted from interspecific crosses showed strong presence of R. rugosa gene pool both in terms of genotype and phenotype.”

This is what I’m seeing here, too, in my rugosa seedlings from three or four years. That said, I’m starting to notice very subtle differences in a few suggesting they could be of hybrid origin.

“It appears that it was the cross that gave rise to remontancy, neither species parent being especially remontant in their own right.”

I believe this can also happen “spontaneously” with disease resistance (and also plant size). In other words, you can have a seedling more disease resistant than either of the parents (and the other way around as well).

I also believe than within another 100 yrs, the rose will have been selected against blackspot susceptibility sufficiently.

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Don said,

“I would go farther and say that the best place to start is with modern roses.”

At least for my climate, this appears to be true. I also agree on the importance of moschata. Moschata seems to be a trigger for introducing greater climactic adaptability, especially for gigantea derivatives.

Pierre said,

“I would like to hybridize roses with hemispherical plant nice foliage and a spectacular naturally well groomed flower display just as i.e. peonies or camelias.”

I’m not sure what you mean by “hemispherical”, but it sounds like we have basically the same goals. I want to create roses that don’t require pruning as one would Hybrid Tea. I want them to stay compact like a shrub and repeat of their own accord. Many miniatures do this.

You will note many of my seedlings have an informal pom pom type of blossom. This comes from banksia. Like you, I’m also especially attracted to Peony and Camellia looking blossoms.

There’s no doubt the classic high center is very beautiful and the easiest form for most people to understand and relate to. Some of my seedlings also have this characteristic. I will take these in a different direction if I can afford the room.

As for repeat, yes, other species repeat but none to my knowledge cycle as frequently as the original stud Chinas.

It’s of course possible to introduce repeat using other species.

I’ve often thought the best strategy for breeding roses with low water requirements might be to start with roses that do not repeat or possibly repeat in Fall like Moschata.

Moschata in my opinion has much to offer. No doubt you’ve noted repeat present in R. damascena bifera comes from (R. moschata x R. gallica) x R. fedtschenkoana. Gallica just comes along for the ride in this lineage. Damascena bifera is drought resistant in much of California but then so are many Chinas.

I’d be very curious to see what could happen if an amphidiploid version of moschata could be created. I don’t think I’m the first one to come to have this idea. Look at the work of Dr. Robert Basye and you will see he apparently also came to this conclusion.

Although it doesn’t repeat, “Basye’s Amphidiploid” appears to be an attempt to create remontancy from two naturally repeating species whilst elevating them to a tetraploid condition allowing integration into the modern rose genome.

No doubt we’ve just begun to explore possibilities offered by hybrids of this type.

Link: www.helpmefind.com/rose/l.php?l=1.11634

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“It appears that it was the cross that gave rise to remontancy, neither species parent being especially remontant in their own right.”

It is something I experience: I got diverse remontancy expression from species crosses. With a few definitely better than parents and comparable to many historic Chinese vars. By the way yes Slaters, Parson’s, Sanguinea or Mutabilis have still to be superseded on that aspect. And collectively with a few other historical chinese vars likely are the only source for modern roses remontancy.

Remontancy expression rely on a number of components such as hability to rebloom, cycle length, earliness/lateness of first/last flowering etc…

Ample oportunities for creative selection here. Particularly when one consider that for remontancy apparently there are among species more than one genetical control.

About moschata I will play devil’s advocate.

It is among the species that contributed most to modern roses. With gallica it contributed better winter hardiness.

Even if… many characters such as the smaller flowers intentionally were bred out. Never its derivatives being recurent parents in the steady backcross to dominant model breeding strategy applied. Noisettes the only class derived from this species were not bred further.

From the very beginnings all interesting genes were incorporated in modern roses.

Going back to ancestral species or hybrids is a strategy I abandonned as too unproductive.

Robert

Just as HTs Miniatures are in need of genetical diversification/reinvention. I know some have a plant architecture similar to the one I look for. Unfortunately they blackspot like mad despite wichurana ancestry. As I never spray with rare exceptions I cannot grow them here.

About drough resistance we should look for strong roots. Standing out here are banksiae bracteata or roxburghii

is there an implication that maybe the rose needs to be “reinvented” …

Only if you want something new and different.>>

Is there someone among us that does not want new and different roses?

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“Is there someone among us that does not want new and different roses?”

I also will play devil’s advocate and suggest the public at large is resistant to change.

Most only want a better or different version of what they already know.

I’ve been quite surprised at the success of things like ‘Knockout’, but then it is said, timing is everything. This must be true.

I predict people will tire of mundane looking landscape roses relatively quickly. There’s lots of room for improvement, at least in terms of floral quality.

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Public is not so conservative…

Miniatures, Austin’s and its host of followers, Ground Covers are recent successfull out standing rose innovations.

With Knockout as well as Flower Carpets or Meidilands people bought performance.

“Mundane looking”…

An healthy plant is a lot more beautifull than a deseased one.

Public buys it at cost of lost flower sophistication.

Rose lovers are too much resigned to have poor looking plants when environment is less than ideal. Fealing guilty as they do not spray enough. General public want performance and buys it. General public more and more hates spraying.

The longer I am breeding for desease resistance the more I am convinced that rose genus strategy for desease resistance is through genetical diversity.

There but two options: either recover this diversity among modern roses or find it within species.

I do not think the first option effective enough even if actually some apparent progress is made. Just as it were in the past…

Every past and present hybridizer allways select(ed) for healthy strong roses.

Real desease resistance is in species and close to them as demonstrated by pedigrees.

It is obvious that unwilling but consistently species desease resistance was lost when desease proneness was not bred out.

Gallica, moschata, fedtschenkoana, china’s ancestors, multiflora, wichurana, sempervirens… most ancestral species are a lot better at strength and resistance than are modern roses.

Knowing this fact we have to reconsider past breeding strategies and procedures as they led to actual situation.