Domesticating Wild Plants
With so many agricultural crops being contaminated by the gene-splicers, it is useful to know that it is possible to domesticate other plants as replacements. In other cases, where we wish to reinvigorate a cultivated race by crossing with wild species, it is often desirable to domesticate the wildlings before crossing. As Anderson (1939) explained:
"Seldom or never will it be possible to incorporate one or more characters of one species with those of another species without also affecting other characters. If, for instance, we wish to incorporate the earliness of one species with the hardiness of another we shall probably have to content ourselves with combining intermediate hardiness with an intermediate earliness. The readily possible combinations can be thought of as occupying a relatively narrow band from one parental combination, to the F1, to the other parental combination. Anything away from this band can be achieved, if at all, only after a careful program of crossing and selection.
Among the bearded irises, for instance, there has been a concerted attempt by iris breeders to incorporate the yellow of Iris variegata into Iris pallida without bringing along such other variegata characteristics as dwarf habit, foliaceous spathes, a zig-zag stem and pencilling on the haft of the sepals. As a result of this attempt many beautiful new varieties have been produced and although the best of these might be said to approach a yellow Iris pallida they still show unmistakable traces of Iris variegata in other characters beside color.
In the genus Narcissus there has been a prolonged attempt to combine the red corona of the poet's narcissi with the flower form and yellow perianth of the trumpet daffodils. The last decade has seen the introduction of yellow hybrids with long red trumpets, but even in these recombinations the shape of the trumpet and of the perianth is still markedly intermediate."
Rose breeders faced a similar difficulty in combining the deep yellow color of Rosa foetida with the desirable charactistics of the Hybrid Teas. But along with the yellow color, other traits were carried into many lines. Some had the short-lived foliage of foetida, which made them particularly susceptible to blackspot. Others had globular buds, or a flush of red. (See Le Grice, 1976) And many inherited the cold tolerance [preference for growing at low temperatures] of foetida without its hardiness. Such varieties often suffer "winter kill" when the new growth is damaged by late Spring frosts.
In other cases, such as hybrids of Rosa rugosa, breeders simply crossed wild selections of the species with cultivated varieties. A more sensible approach, I think, would have been to do some selective breeding of rugosa, along with crosses among accessions, to reduce the juvenile period. These selected forms of rugosa, flowering the first year from seed (and with different colors and degrees of doubling), could then be crossed with cultivated roses. The progeny should give better results, even in the F1 generation. Repeated backcrossing to cultivated types tends to dilute whatever desirable characteristics rugosa has to offer.