Breeding of Modern Rose Cultivars Decreases the Content of Important Biochemical Compounds in Rose Hips.

This study aimed to determine the content and composition of bioactive compounds in autochthonous rose hips (R. pendulina, R. spinosissima, and R. gallica) and to compare them with the content of bioactive compounds in some cultivars ('Harstad', 'Bourgogne', 'Mount Everest', 'Poppius', 'Fruhlingsduft', 'Single Cherry', 'Fruhlingsmorgen', 'Violacea', and 'Splendens') derived from these main species. Due to insufficient information on how bioactive compound content changes when crossing roses, this study also sought to ascertain whether modern rose hip cultivars are still a sufficiently rich source of bioactive compounds and could, therefore, be potentially used as a functional food. All material was collected in the Arboretum Volcji Potok (Slovenia). The ascorbic acid content was highest in the 'Harstad' cultivar (12.79 g/kg FW), and the total organic acid content varied from 1.57 g/kg FW (R. spinosissima) to 34.39 g/kg FW ('Harstad'). Of all the carotenoids analyzed, only lycopene and ß-carotene were present in all the samples. The total carotenoid content was highest in the 'Fruhlingsmorgen' cultivar (100.84 mg/kg FW), derived from R. spinosissima, and lowest in the main species, R. spinosissima (9.26 mg/kg FW). It can be concluded, therefore, that the content of bioactive compounds in rose hips of modern cultivars is generally lower than in rose hips of old cultivars and original species included in this study. The research results confirm that modern breeding strategies are mainly focused on goals such as abundant flowering and resistance to diseases and pests and not so much on the content of bioactive compounds.

Detailed Metabolic Characterization of Flowers and Hips of Rosa gallica L. Grown in Open Nature.

Our research aimed to investigate the primary and secondary metabolites of rosehips and petals of R. gallica in comparison with R. subcanina. R. gallica was chosen because it is still unexplored in terms of various bioactive substances and is strongly present in Slovenia. Given that roses are generally very variable and unstudied, our research will contribute to greater transparency and knowledge of the bioactive composition of rosehips and petals. We found a strong positive correlation between the total content of phenolics and ascorbic acid, between the total content of organic acids and the total content of carotenoids, and between the total content of sugars and the total content of organic acids. Hips of R. gallica contained higher amounts of sugars, ascorbic acid, and carotenoids than R. subcanina. Based on the composition of phenolic compounds in the petals, it is possible to distinguish between the two species. Among all the phenolic compounds in the petals, both genotypes are richest in gallotannins, followed by flavonols. Among anthocyanins, cyanidin-3-glucoside was determined, the content of which was also higher in R. gallica. It can be concluded that the studied hips had an extremely low sugar content and, consequently, an extremely high organic acid content. The content of carotenoids in hips was in the lower range of the average content compared to data from the literature. By optimizing the harvesting time, we could obtain a higher content of carotenoids, which could potentially be used for industrial purposes. However, we found that the analyzed petals were a rich source of phenolic compounds, which benefit the human body and could be potentially used in the food and cosmetic industries.

Phenolic Compounds of Rose Hips of Some Rosa Species and Their Hybrids Native Grown in the South-West of Slovenia during a Two-Year Period (2020-2021).

The genus Rosa is very extensive and variable, so it remains very unpredictable and uninvestigated. This also holds true for values of secondary metabolites in rose hips, which are important for several purposes (human diet, protection of plants against pests, etc.). The aim of our study was to determine the content of phenolic compounds in the hips of R. × R. glauca, R. corymbifera, R. gallica and R. subcanina, which grow wild in nature in southwestern Slovenia. We examined the content of phenolic compounds in different parts of rose hips, in the flesh with skin and in the seeds, depending on the individual species, over a period of two years, 2020 and 2021. We also considered the influence of environmental conditions on the content of the mentioned compounds. In both years, the content of phenolic compounds was higher in the flesh with skin than in the seeds. Considering the total content of phenolic compounds in the flesh with skin, R. gallica stands out (15,767.21 mg/kg FW), but the hips of this species accumulated the lowest number of different phenolic compounds. The lowest content of total phenolic compounds (TPC) was found in R. corymbifera, in the year 2021 (3501.38 mg/kg FW). The content of TPC (in both observed years) in the seeds varied between 1263.08 mg/kg FW (R. subcanina) and 3247.89 mg/kg FW (R. × R. glauca). Among the anthocyanins, cyanidin-3-glucoside was determined, which was predominant in R. gallica (28.78 mg/kg FW), and at least was determined in R. subcanina (1.13 mg/kg FW). When comparing the two years of the period (2020-2021), we found that 2021 was more favorable for the formation of phenolic compounds in the seeds, but 2020 in the flesh with skin.

Characterization of the Slovene Autochthonous Rose Hybrid Rosa pendulina × spinosissima (Rosa reversa Waldst. and Kit) Using Biochemical Patterns of the Plant Blossoms.

The Rosa genus is characterized by great variability and, consequently, they easily hybridize. The petals of R. pendulina, R. spinosissima and their hybrid Rosa pendulina × spinosissima, collected in western Slovenia, were included in the research. We performed morphometric analysis using keys to determine roses and genetic analysis to determine the genome size. The phenolic compound content in petals of all rose flowers was measured by liquid chromatography and mass spectrometry (HPLC-MS). Using flow cytometry, we could confirm the native hybridization process due to the amount of 2C DNA. The value of R. pendulina was 1.71 pg, of R. spinosissima 1.60 pg and of the hybrid 1.62 pg. The value for the hybrid was close to values measured for parent plants and, at the same time, those values of parent plants significantly differed from each other. Our results showed that the content of phenolic compounds in petals decreased after crossing. We found that the highest total phenolic content (178.9 g/kg FW) was measured in R. spinossisima, the lowest content was analyzed for the hybrid (84.36 g/kg FW) and the content for R. pendulina was between these two values (110.58 g/kg FW). The content of flavanols and flavonols was lowest in the hybrid petals, whereas the content of anthocyanins was highest in the hybrid petals.

Essential Oil and Hydrosol Composition of Immortelle (Helichrysumitalicum).

The chemical composition of essential oils and hydrosols of immortelle (Helichrysum italicum) stems with leaves obtained by hydrodistillation was identified using gas chromatography coupled with mass spectrometry (GC-MS). One-year-old and two-year-old plants of the same immortelle population, and plants from three Croatian populations, all grown in Slovenia, were included in the study. The main compounds of essential oils of one-year-old and two-year-old plants were α-pinene, α-eudesmol, and rosifoliol. Among essential oils of the Croatian populations, three dominant components were found: α-pinene, geranyl acetate, and 2-phenylethyl tiglate. Both the essential oils and hydrosols of one-year-old plants were more diverse in their compositions than two-year-old plants. The predominant compounds of hydrosols of one- and two-year-old plants were pentan-3-one, 3-octanone, 2,2-dimethylnon-5-en-3-one, and α-terpineol, and in the Croatian populations α-terpineol, 2,6-octadien-1-ol, 2,2-dimethylnon-5-en-3-one, and α-terpineol.