I hope no one minds a friendly discussion, so please accept the following as an attempt to just add another point of view to the discussion.
Jim, your opinions are highly valued, and I hope my own haven’t seemed less than friendly. I am really enjoying this discussion.
…rose breeders are now trying to breed in desirable traits
Agreed, though not much has been published about their philosophical approach. Liz wrote earlier about Kordes’ efforts beginning in the 1990’s (see http://www.rosehybridizers.org/forum/message.php?topid=13009#13244), and from her description of Kordes’ test beds we can guess that they are selecting rigorously for disease resistance, but against which particular gene pools seems to be a trade secret given that the Kordes are no longer disclosing their roses’ parentage.
I wonder how many desirable recessive traits there are in our own modern roses, just waiting to be “found”.
There may be a few opportunities left within the genes of modern roses. For instance, I think fragrance improvement can probably be accomplished without resort to species infusion, but will benefit by going back to old garden roses (which the institutional breeders are obviously doing, witness Austin’s successes). However, we can see from both genetic studies and scrutiny of the database at helpmefind.com that modern roses spring from a mere handful of ancestral cultivars whose genes have been mixed over and over and over to the point where it is likely that most possible phenotypes have appeared and been selected for or against repeatedly.
I think there are many more opportunities lurking in the wild than in roses already under cultivation. As I have proved to myself recently, these opportunities are going to be very hard to find and reach.
The manipulation of traits like color and form were the first to be mastered for three reasons: they are relatively simple biochemical systems having correspondingly small numbers of genes; the phenotypes are profoundly obvious making selection a simple matter; and the market places high value on them.
Traits like fragrance, disease resistance and rooting behavior have far more complex biologies, require greater time and effort for evaluation, and are not critical for marketplace success. This is especially true of disease resistance. In fact, I disagree with any assessment that the marketplace is now demanding disease free roses.
While I applaud the efforts of the Earthkind folks, it is more the growers and marketers of roses who want improved disease resistance because it would decrease production costs and (they hope) give them a competitive advantage in the marketplace.
The same thing can even be said about hardiness. The public has proved that it is quite willing to treat roses as annuals, and as the retail costs continue to come down this will increasingly be the case. Who cares if you have to plant new rose bushes every year if they cost five bucks at Walmart? Add to this the fact that your lawn care service is quite willing to spray the rose bed for a small additional charge and you’ve conquered the biggest barriers to growing roses.
the more dominant resistant genes would be selected for and the more recessive resistant genes would become dilute…What we really need is a way to artificially link as many of the resistant genes involved in horizontal resistance and splice them into existing modern roses.
It is probably a mistake to regard disease resistance as having simple Mendelian inheritance, and it is anyway unnecessary to understand in detail the mechanisms involved in order to breed and select for it.
Nor do I hope for an engineering solution to the problem, in fact I hope this does not happen. Classical methods allow me to legally breed with the progeny, but an engineered solution would be put the “invention” of a disease resistance mechanism off limits, except by license, for 20 years. This is, incidentally, also true of Suntori’s putative “blue” rose supposedly in the pipeline at J&P.
The issue with using the phrase, desirable traits, is that it is partially objective
How true, and the problem is compounded with systems in which the goals are highly complex and abstract. Yet sometimes opportunity lies in altering one’s paradigm or even just thinking outside the box. For instance, there was a discussion a few weeks ago here about the phenomenon of extreme proliferation (see http://www.rosehybridizers.org/forum/message.php?topid=17365). I have never seen this occur, but Timo’s picture made me wonder: what might happen if this trait were selected for rather than against? It might be possible to take this trait to some limit beyond the grotesque and develop an entirely new flower form, say Rosa multicorolla timoflora.