title: Chemical and histochemical analysis of 'Quatre Saisons Blanc Mousseux', a Moss Rose of the Rosa x damascena group.
abstract: OBJECTIVE
  Moss roses are old garden roses covered with a mossy growth on flower pedicel and calyx. This moss releases a pine-scented oleoresin that is very sticky and odoriferous. Rosa x centifolia 'muscosa' was the first moss rose to be obtained by bud-mutation but, interestingly, R. x damascena 'Quatre Saisons Blanc Mousseux' was the first repeat-blooming cultivar, thus interesting breeders. In the present study, the anatomy of these sports (i.e. bud-mutations) is characterized and the volatile organic compounds (VOCs) produced by the moss versus the petals are identified. They are compared between the two lines and their respective parents.
  
  
  METHODS
  Anatomy of the moss is studied by environmental scanning electron microscopy and histochemical light microscopy. Sudan Red IV and Fluorol Yellow 088 are used to detect lipids, and 1-naphthol reaction with N,N-dimethyl-p-phenylenediamine to detect terpenes (Nadi reaction). Head-space or solid/liquid extraction followed by gas chromatography and mass spectrometry are used to identify VOCs in moss, trichomes and petals.
  
  
  RESULTS
  Moss of the two cultivars has the same structure with trichomes on other trichomes but not exactly the same VOCs. These VOCs are specific to the moss, with lots of terpenes. An identical VOC composition is found in leaves but not in petals. They are nearly the same in the moss mutants and in the respective wild types.
  
  
  CONCLUSIONS
  Sepals of moss roses and their parents have a specific VOC pattern, different from that of the petals. The moss corresponds to a heterochronic mutation with trichomes developing on other trichomes. Such a mutation has probably appeared twice and independently in the two lines.
authors.affiliation: Laboratoire BVpam (Biotechnologies Végétales, plantes aromatiques et médicinales), EA 3061, Université Jean Monnet, 23, rue du Docteur Paul Michelon, 42023 Saint-Etienne cedex 2, France.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Caissard
authors.forename: Véronique
authors.initials: V
authors.lastname: Bergougnoux
authors.forename: Magali
authors.initials: M
authors.lastname: Martin
authors.forename: Mélanie
authors.initials: M
authors.lastname: Mauriat
authors.forename: Sylvie
authors.initials: S
authors.lastname: Baudino
mesh_terms: D002849:Chromatography, Gas; D003433:Crosses, Genetic; D035264:Flowers / Q000033:anatomy & histology / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D039821:Monoterpenes / Q000032:analysis; D010802:Phylogeny; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000033:anatomy & histology / Q000737:chemistry; D027826:Rosa / Q000033:anatomy & histology / Q000737:chemistry* / Q000145:classification
chemical_list: D039821:Monoterpenes; D010936:Plant Extracts