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