Breeding Roses (this comes in handy for biology if your studying plants and need some extra credit)
Uploaded by Sheryu on May 12, 2005
Every rose breeder has certain more or less definite ideals or objectives toward which his breeding
efforts are directed. Some of these ideals are shared by all rosarians, while others express the individuality of the breeder and may or may not find popular acceptance. Thus in my opinion an ideal red rose, for example, should have the following characteristics:
1. ) Vigor similar to Radiance
2 .) Long pointed or urn-shaped buds such as Lulu, Eclipse, or Charlotte Armstrong.
3 .) Glossy or semi-glossy, hard, leathery foliage.
4 .) High degree of mildew and rust resistance.
5 .) Everblooming, rapid "breaking habit".
6 .) Long cutting stems.
7 .) Strong neck.
8 .) Fragrance.
9 .) Absence of blue fading reaction. World's Fair is ideal in this respect.
10.) A high-centered open flower with 25 to 35 large petals.
Breeding Plan
Although the rose which perfectly meets these ideals may never be developed, any variety which is a step toward perfection is worthy of introduction. In my own experience most rapid progress toward combining all the above characteristics in one plant may be made by crossing variety A, having such desirable characteristics as mildew resistance and large glossy leaves, with variety B, having double dark red flowers but dull foliage, susceptibility to mildew, and short buds (unfortunately characteristics of most red roses so far introduced).
Simultaneously variety A is crossed with variety C, having long buds, vigorous growth, and deep pink or light red flowers (hence carrying factors for red). Hybrids from cross A x B having wide glossy leaves, a high degree of mildew resistance, and deep pink or light red double flowers are then crossed with pink-flowered hybrids of A x C having the longest buds and most vigor. Large progenies must be grown in order to get the best combination of characteristics in a very few plants. These sister seedlings with wide glossy leaves, mildew resistance, and fairly long buds, are then crossed together, and in the resulting generation deep red roses having a vigorous growth habit, a high degree of mildew resistance, large glossy leaves, very long buds, and sufficiently double flowers may be expected. In order to understand the need for this type of breeding procedure, a discussion of rose chromosome numbers and behavior as they affect the inheritance of important characteristics is necessary.
Mechanics of Inheritance
Biologists are agreed that the factors determining the characteristics of plants and animals are serially located in certain deeply staining bodies of the cell...