MOLECULAR GENETIC STUDIES ON CONTINUOUS-FLOWERING ROSES THAT DO NOT ORIGINATE FROM ROSA CHINENSIS
The Continuous-Flowering (CF) behavior of modern roses is considered to originate from a Chinese rose, Rosa chinensis. In R. chinensis, an insertion of a copia-like retrotransposon is present in the floral repressor gene KSN, and it blocks the maturation of transcripts of the gene and allows the rose to flower continuously. Most modern CF roses are expected to have this mutated allele of KSN (ksncopia). Because of this narrow genetic background of CF modern roses, we aim to discover the CF roses that have no ksncopia allele, which will be good breeding materials for novel CF roses. We also aim to test the possible involvement of KSN in the regulation of CF behavior in the novel CF species, R. rugose. By genotyping of KSN we found that the CF species (R. rugosa) have only a wild KSN allele without the insertion, indicating that its CF behavior has a different origin than that of . Sequencing analysis did not find any obvious mutations in the KSN gene of R. rugose, and the seasonal expression of KSN was clearly linked with the alternation of flowering/vegetative stages of shoot apices in R. rugose. Thus, KSN is involved in the control of CF behavior of R. rugose, although it is not simply explained by the mutation in coding region of KSN. In order to uncover the genetic determinism of CF behavior in R. rugose, cross hybridization and Quantitative Trait Loci analysis of segregating population for flowering-behavior is necessary.
Horibe, T., Yamada, K., Otagaki, S., Matsumoto, S. and Kawamura, K. (2015). MOLECULAR GENETIC STUDIES ON CONTINUOUS-FLOWERING ROSES THAT DO NOT ORIGINATE FROM ROSA CHINENSIS. Acta Hortic. 1064, 185-192
Rosa rugosa, Rosa multiflora, Rosa bracteata, TERMINAL FLOWER 1, KSN, Recurrent-flowering