Comparing ornamental and other quality traits of Rosa rugosa hybrids in Latvia

In this report, we summarize results of the continuous analysis of the diversity in R. rugosa in Latvian breeding programs focusing not only on ornamental but also on functional traits. The quantity of pigment groups (anthocyanins, carotenes and a and b chlorophylls), composition of volatile compounds and free radical scavenging activity (1,1-diphenyl-2-picryl-hydrazil (DPPH) % inhibition) was measured in the leaves and petals of the cultivars 'Ritausma', 'Sniedze', 'Zaiga', 'Liga', 'Frau Dagmar Hastrup', R. rugosa and R. rugosa 'Plena'. Spectrophotometric quantification of pigments identified variation in content and composition of the pigments in leaves and petals. The hydrogen atom or electron donation abilities of the corresponding extracts were measured from the bleaching of the purple-colored methanol solution of DPPH. The absorption was read against a blank at 517 nm. Volatiles from roses were extracted using solid phase microextraction (SPME) with subsequent separation by gas chromatography and identification by comparison of their mass spectra with mass spectral libraries (Nist98). Forty two volatile aroma compounds were identified in petals. Among those, phenylethylalcohol, betacitronelol and nerol were predominant, but the composition of compounds varied among cultivars. The cultivar 'Sniedze' scavenged ∼90% of free radicals, which was the best result for rugosa hybrids. R. rugosa 'Plena' had the richest and strongest content of volatiles, but the pedigree of all cultivars, R. rugosa, exhibited the highest free radical scavenging activity (91.26% of total amount) and contained 7.8 mg anthocyanins in petals per 100 g of fresh weight. Thus, in addition to its ornamental value R. rugosa appeared to be preferable for use as a source of volatile compounds and healthy, colorful tea.