XXIIIrd International Eucarpia symposium, Section Ornamentals ...

GROWTH AND DEVELOPMENT OF CUT ROSE
CLONES; INDIRECT SELECTION FOR YIELD
The shoot yield of 177 large-flowered own-rooted cut rose genotypes, grown in a heated
glasshouse, was recorded for 40 weeks in year # 1. These genotypes showed a normal
distribution over 8 yield classes : 420 shoots plant -1 . 5 Genotypes from each
yield class (total of 40 genotypes) were propagated as cuttings and planted in the
glasshouse early year # 2. The growth and development of these young plants were
studied until each plant had 2 bottom-breaks (Bb). The mean number of days to the
appearance of the 1 st and the 2 nd Bb, were 43.1 and 57.1 days after planting; days to
flowering of these shoots took 35.5 and 34.2 days from their appearance; at flowering
the shoot lengths were 77.5 and 83.4 cm; mean length increases were 23 and 26
mm.day -1 . Highly significant negative correlation (r = - 0.69 +++ ) between the shoot yield in
year # 1, and the number of days to appearance of the 1 st Bb of the same genotypes in
year # 2, shows unique possibilities to indirect selection for future yield of clonal plants.
The probable role of endogenous hormone action in the carbon partitioning in rose
plants is discussed.
L25
D.P. de Vries 1)
L.A.M. Dubois (2)
(1) Foundation Sub Rosa,
P.O.B. 4097, 6710 EB Ede,
The Netherlands
(2) Plant Research
International (PRI), P.O.B.
16, 6700 AA Wageningen,
The Netherlands
devriesrosa@hetnet.nl
Session Breeding and Genetics 51