(2017)  
 
In its origins “Félicité et Perpétue” is a diploid hybrid between a recurrent-flowering rose, probably a Noisette rose, and R. sempervirens which is seasonal flowering. From the Noisette rose it inherited the disabled form of RoKSN and from R. sempervirens it inherited wild-type RoKSN. Both forms of RoKSN can be detected in shoot apices of “Félicité et Perpétue” but only the disabled RoKSN can be detected in “Little White Pet” (Iwata et al., 2012). This indicates that the mutation from “Félicité et Perpétue” to “Little White Pet” resulted from a deletion of wild type RoKSN.

(2017)  
 
The wild-type homologue of the recessive gene for seasonal flowering in roses has been named RoKSN, where Ro stands for rose and KSN for “Koushin”, the ancient Japanese name for recurrent-flowering Rosa chinensis (Iwata et al., 2012). 

(2017)  
 
In its origins “Félicité et Perpétue” is a diploid hybrid between a recurrent-flowering rose, probably a Noisette rose, and R. sempervirens which is seasonal flowering. From the Noisette rose it inherited the disabled form of RoKSN and from R. sempervirens it inherited wild-type RoKSN. Both forms of RoKSN can be detected in shoot apices of “Félicité et Perpétue” but only the disabled RoKSN can be detected in “Little White Pet” (Iwata et al., 2012). This indicates that the mutation from “Félicité et Perpétue” to “Little White Pet” resulted from a deletion of wild type RoKSN.

(2017)  
 
Recurrent-flowering roses frequently mutate to a climbing habit in which the first flush of flowers in spring is followed by a second flowering late in the growing season. The climbing mutants differ from the original cultivar in producing more nodes before the iflorescence is initiated, not by an increase in the length of internodes. They arise from a mutation that occurs within the transposon that disabled RoKSN and involves a reduction of 9-kbp transposon to a 1-kbp fragment of DNA (Iwata et al., 2012). This reduction results in a partial reversion to seasonal flowering. In the diploid climbing rose “Old Blush Cl.” the only form of RoKSN present is that with the 1-kbp fragment.

(2017)  
 

Recurrent-flowering sports of Rosa chinensis were found, cultivated and bred in China about 1000 years ago (Guoliang, 2003). Modern-day recurrent-flowering cultivars were bred from these sports. The gene responsible for this characteristic is a mutant gene that is recessive to its wild-type allele and F₁ hybrids between recurrent-flowering cultivars and wild roses are seasonal-flowering. It is generally the case that a recessive mutant gene is a damaged gene that is unable to function normally. In the case of the recurrent-flowering gene the ability that has been lost is the restraint of flowering. Recently information has emerged at the molecular level, on how this happens.
The wild-type homologue of the recessive gene for seasonal flowering in roses has been named RoKSN, where Ro stands for rose and KSN for “Koushin”, the ancient Japanese name for recurrent-flowering Rosa chinensis (Iwata et al., 2012). RoKSN encodes a protein called RoKSN (written without italics). RoKSN is activated (transcribed into mRNA) when gibberellins are present in shoot apices in a sufficiently high concentration. RoKSN is then produced which prevents the initiation of flowers (Randoux et al., 2012; Remay et al., 2009).