Wichuraiana is a good example of the possible diverse breeding strategies.
It is the better species when one consider desease resistance. Never spots nor mildews.
To the point it is where german scientific Thomas Debener is looking for a resistance gene to patent and incorporate in succeptible cvs.
This single gene strategy mostly has failed for the easier breeding plants and historicaly for roses.
Wichuraiana use in breeding new roses began around 1900 when it was a fashionable parent for more pliable wooded ramblers. Dorothy Perkins being the better known. Initialy very clean it is a martyr to PM in most places.
Further used at breeding polyanthas, Floribundas and ultimately Hts that are distinguished by not better than average at desease resistance glossy leaves.
Recently it was and is still used a lot by Ralph Moore and other stepping on his shoulders mini breeders. Wichuraiana contribution here is smaller plant parts. Desease resistance has gone with back crosses to Hts and Fls.
Nevertheless desease resistance is here as are showing many successfull Ground Cover cvs whose breeding include the quite unusual back crosses to the species.
Here we have the main alternative breeding strategy: finding new formats, unfolding and developing new genes expressions. Sibcrossing and backcrossing as often as needed to maintain a (new) species strength and resistance.
Most successfull new ventures in breeding programs are along this line with Moore, Noak, Warner and wichuraiana or Austin, Guillot, Poulsen, Meilland and gallica.
Of which Moore, Noak, Warner, Austin and Guillot (Massad) more or less started as amateurs.
If we can play with the big breeders without investing a lot of time and money we cannot realy compete.
For us amateurs exploring new species and new formats is much more promising. And more exciting as when going out of beaten pathes: perseverance, open mind and imagination are needed more than a lot of money.
Which new species? Nobody knows as the obvious ones have been exploited!
The better oportunities are probably looking at diversity either in the relictual Hulthemia, Hesperodos, Banksiae, Laevigatae, Minutifoliae, Pimpinellifoliae and the mostly unexplored and very diverse Cinnamomae that many think should include Carolinae.
With open mind and imagination!