Many of the flowers of present-day rose varieties are as beautiful as roses can be, but why do the plants lack sturdiness?
When a selection is made from many seedlings produced by crossing two parents, all the seedlings differ one from the other, much as the children of two parents differ. One may be beautiful and weak; another strong, sturdy, and not so handsome.
So it is in plant life. The breeder may select one plant variety from a long list of hybridized seedlings for its lovely flower, regardless of its sturdiness.
Repeating this practice for several generations, it is clear that, by successive selections, we may have obtained a variety with superb flowers borne on a conspicuously weak plant.
That is what has happened with the greater part of rose-breeding in former years because work has been done with limited resources for more than a century.
Improved Newly Introduced Rose Varieties
To have been selected for both bloom and sturdiness would have often required labor and expense. However, recently introduced varieties show improvement in both flower and sturdiness of the plant.
What do we want for the future? We want roses that will live for decades, plants free from blackspot, and specimens that care for themselves on the border.
We want individual shrubs, in variety, that will grow our favorite blooms, armfuls of them for daily decoration until frost — one or two hundred blooms or more per plant each season.
And we want specimen bushes on the lawn with full to completely rebloom sizes as large and tall as a lilac, a mock-orange, or a hydrangea.
We would like, too, climbing forms to spray on garage roofs — forms that will bloom all summer like the most prolific hybrid tea or wind spirally around a pole, with total fluorescence until frost.
Such plants should flower all summer freely, producing as rapidly as they can grow stems, and both shrub types and climbers ought to bloom the first year freely from the base like hybrid teas.
Rose Types Of The Future
How can we have all these features and more? To fully appreciate the rose types of the future, it is important to realize that nothing can be added by breeding two plants together.
The resultant seedlings will only inherit a rearrangement or recombination from the character-determiners of the two parents because there are only two types of floral expression in the genus Rosa — the “once bloom” and the “ever bloom” form. This distinction is most important.
Some would define the “once bloom” as stems from wood grown a previous year that does not usually repeat.
“Everbloom” might be explained as all growth being bloom stems, setting one or more flowers after about 6 to 12 leaves. We call the latter hybrid teas, polyanthas, floribundas, and monthly roses.
It is important to note that the cross of “once bloom” with “everblooming” is only on some of the most learned.
Even if I could, I would not inflict upon you the intricate scientific approach to the inheritance processes that function to produce new things for the garden.
But when you can grow your favorite rose among shrubs and gather the blooms all season long from bushes as tall as your head that require no special attention or when you see on the roof of the garage climbers flowering as do hybrid teas, then the questions will come to mind.
How could it happen? Why did we not have these things before? Then, in explanation, we have seen that:
- It could not happen by hybridizing.
- It could not happen by the environment.
- It could only happen through variations, that is to say, changes in the constitutions, which are the character determiners of growth and performance of the variety.
What Is A Variation Or Sport?
These plants are composed of innumerable cells. The center, or nucleus, of each, contains the character-determiners, and these are the things that the hybridizer breeds.
Of course, he does it by applying the male pollen to the female part that grows the seed.
This is possible only because these cells are the plant itself, beginning with the seed from which it grew and continuing to the specially prepared cells for reproduction in the flower.
Thus, the seedling receives only a combination of characters from the two parents, one that supplied the seed and the other the pollen, and nothing new can be added by this breeding process.
That recombination may produce a very interesting rose variety; as we have seen, each such offspring will be different from its sister. It cannot produce variations, or sports, to develop the future, everblooming roses we seek.
Unusual Characteristics
Why do we go into it if the usual breeding procedure cannot produce what we want? Because that is the normal variations are not normal procedures, but they can perform the needed procedure.
Whether we call these new types variations, sports, or mutations, they come into being usually by a change in a cell, adopting characters not active but latent in the plant itself. These sports may reveal various unusual characteristics in color, form, or type of growth.
Such sports represent primarily only one change in one cell of a plant which, by self-division, is repeated again and again, thousands of times. Thus a branch or stem can be grafted and grown by regrafting into unlimited numbers of that same new variety produced as a variation.
This sported cell may combine with one not sport, or even another sported cell, to form a new variety or sort of twin variation to grow a plant with constitutional characteristics of two parents that normally could not obtain.
Hence, this specific variation — or another in combination with still other new varieties — may be the very one we seek to give us hybridizing material that will breed best for us.
In essence, the pursuit of variations in roses that will produce the ideal plants for the gardens of tomorrow is accomplished only by long years of patient work.
However, the roses in our trial grounds today hold great promise. What could be more rewarding after a lifetime devoted to working with the Queen of Flowers?
44659 by W. D. Brownell