Abstract:

Perpetual blooming is one of the most important trait of ornamental plant，and it is the huge
contribution of Chinese rose（diploid rose）to modern rose（tetraploid rose）breeding. However，the genetic
basis of this trait is still largely unknown. In order to investigate the inheritance of perpetual blooming
behavior in Rosa chinensis‘Old Blush’（OB），we developed six rose populations（OB，W，F1，F2，
BC1OB and BC1W）derived from WOB population[interspecific diploid hybrid between OB and Rosa
wichuriana‘Basye’s Thornless’（W）]. Perpetual blooming trait was analyzed as a major gene，and
blooming behavior of each individual was evaluated at Flower Research Institute，Yunnan Academy of
Agricultural Sciences（Kunming，China）from 2012 to 2015. Perpetual blooming type is absent both in a
F1 population with 296 genotypes and a BC1W population（Rosa wichuriana‘Basye’s Thornless’as a
backcross parent）with 150 individuals. More interesting is，a backcross population BC1OB（Rosachinensis‘Old Blush’as a backcross parent）with 300 progenies showed a 3︰1（P < 0.05）segregation ratio
in blooming behavior（non-perpetual blooming dominant to perpetual blooming）. The results indicate that
the inherence of perpetual blooming in rose might be regulated by double recessive loci.

Key words: rose, Chinese rose, perpetual blooming, segregating population, double recessive
loci