Chemical and histochemical analysis of 'Quatre Saisons Blanc Mousseux', a moss rose of the Rosa x damascena group

Jean Claude Caissard (1) , Véronique Bergougnoux (1) , Magali Martin (2) , Mélanie Mauriat (1) , Sylvie Baudino (1)

1 BVPAM - Laboratoire de Biotechnologies Végétales appliquées aux Plantes Aromatiques et Médicinales
2 GEPS (EA3731) - Génome et Evolution des Plantes Supérieures

• Background and Aims 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 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 (ESEM) and histochemical light microscopy. Sudan red IV and Fluorol yellow 088 are used to detect lipids, and 1-naphtol reaction with N,N-dimethyl-p-phenylenediamine to detect terpenes (nadi reaction). Headspace or solid/liquid extraction followed by gas chromatography and mass spectrometry are used to identify VOCs in moss, trichomes and petals. • Key Results Moss of the two cultivars have the same structure with trichomes on other trichomes but not exactly the same VOCs. These VOCs are specific of the moss, with lots of terpenes. An identical VOC composition is found is leaves but not in petals. They are nearly the same in the moss mutant and in the respective wild types. • Conclusions Sepals of moss roses and their parents have a specific VOC pattern, different from the petals one. 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.

Mots clés: Rosa x damascena 'bifera'; Rosa x damascena "Quatre Saisons Blanc Mousseux"; Rosa x centifolia; Rosa x centifolia ‘muscosa'; moss roses; glandular trichomes; histochemistry; volatile organic compounds; gas chromatography; sport; terpenoids; benzenoids; Rosa x damascena 'bifera; Rosa x damascena "Quatre Saisons Blanc Mousseux; Rosa x centifolia ‘muscosa

Domaines: Amélioration des plantes; Morphogenèse; Systématique, phylogénie et taxonomie

Jean Claude Caissard, Véronique Bergougnoux, Magali Martin, Mélanie Mauriat, Sylvie Baudino. Chemical and histochemical analysis of 'Quatre Saisons Blanc Mousseux', a moss rose of the Rosa x damascena group. Annals of Botany, 2005, 97 (2), pp.231-238. ⟨10.1093/aob/mcj034⟩. ⟨ujm-00080719⟩