The plant materials in the study include rosehip (R. canina L.), Yildiz variety of rosehip (R. canina L. cv ‘Yildiz’), Syrup rose (R. heckeliana Tratt. subsp. vanheurckiana), Austrian briar (R. foetida Herrm.), lax rootstock [R. caesia Sm. (Syn: R. laxa Retz.)], wild rose [R. montana subsp. woronovii Chaix subsp. woronovii (Lonacz) Ö. Nilsson L.], hybrid landscape roses (R. x hybrida) and Hosap rose [R. pisiformis (Christ) D.] taxa. The taxa names are written in full at this stage, and in other parts of the research, they are given in a short form without authorization.

Cuttings belonging to the taxa were taken from Van Yüzüncü Yıl University Faculty of Architecture and Design, Landscape Architecture Department Research Fields and Tokat Gaziosmanpaşa University Faculty of Agriculture Department of Horticulture Research Field. The literature of Brummitt and Powell (1992) was taken as a reference for the standard spelling of scientific names of species and subspecies, including the authors (abbreviations), and was examined by considering the UPOV (2010) criteria.

Among the plants belonging to these taxa, only the registered varieties belonging to four taxa were used, while the others were genotypes. In the study carried out under greenhouse conditions, the greenhouse temperature was measured with an Onset Computer H21-001 HOBO brand thermometer and the average annual temperature was determined as 24.73 °C. This value was determined as a result of measurements made for 24 months. It was determined that the pH of the growing medium in which the study was carried out was 7.14 and had a clay/loamy structure. The lime content was determined as 6.14% and the salt content was 0.04 %.

The data from analysis and measurements were subjected to Analysis of Variance (ANOVA) in the Minitab 18 computer package program. Differences between means were expressed by grouping according to ANOVA and compared among themselves according to the LSD 5% level.

In this study, the seed fatty acid compositions of Rosa L. taxa (R. montana subsp. woronovii, R. foetida, R. laxa) which had not been studied before were determined. In addition to these taxa, the seed oil contents of previously studied taxa R. canina, R. heckeliana, R. pisiformis and hybrid landscape rose seeds were also investigated (Szentmihalyi et al., 2000; Nowak 2005; Ercisli 2007; Machmudah et al., 2007; Kazaz et al., 2009; Celik et al., 2010; Prescha et al., 2014, İlyasoğlu, 2014; Turan et al., 2018; Kizil et al., 2018; Vasic et al., 2020). As a result of the study, the different values for R. canina and R. canina ‘Yildiz’ seeds obtained under the same ecological conditions and from the same species show that the fatty acid compositions may vary not only on the basis of species, but also according to varieties. In this context, the oil content in the seeds of the Rosa L. taxa, which is the subject of this research, was determined and statistical evaluations were made for the years 2020, 2021 and the average of the two years (Table 1).

According to the average values of the two-year data, although the seed oil contents varied according to the species and subspecies, the difference between the years was found to be statistically insignificant (p > 0.05).

Considering the descriptive statistics, the seed oil contents from 2020 varied between 3.79 and 10.06% and the average value of the investigated taxa was 6.83%. The seed oil contents from 2021 ranged between 3.64 and 9.96% and the average value of the investigated taxa was 6.78%. According to the data obtained, R. montana subsp. woronovii seeds had the lowest seed oil content in 2020 and 2021, and the R. heckeliana species had the highest seed oil content.

Ercisli (2007) studied six taxa and found that the oil content was between 4.60 and 5.37%. In this context, when the seed oil contents of the Rosa L. taxa used in this research were taken into account, it was determined that the data obtained were comparable to the literature data. When the relevant literature is examined, it is possible that the differences in fatty acid composition may be related to environmental conditions (climate and altitude, etc.), which are known to have an effect on fatty acid composition (Ilyasoglu, 2014). The subspecies were determined to have a value above the average (10.01%).

In recent years, research on different fruit oils in the cosmetic and food industries has increased and alternative products have begun to be examined in more detail. The seeds from different rose species examined within the scope of this research can be considered as a fruit oil source with its 3.71-10.01% oil content.

According to the analyses made on the eight Rosa L. taxa investigated, these taxa contain an average of 91.62% unsaturated fatty acids and 8.38% saturated fatty acids (Figure 1). These rates are 96.17 - 3.83%, respectively, in the studies by Nowak (2005), 85% and 15% according to Macmudah et al. (2007), and in the studies by Kazaz et al. (2009), they were determined as 91.1% and 8.90%. Therefore, it has been concluded that the results obtained in this research are comparable to the literature data in question.

Unlike data from the literature (McGaw et al., 2002; Nowak, 2005; Ercisli, 2007; Machmudah et al., 2007; Kazaz et al., 2009; Kizil et al., 2018; Vasic et al., 2020), it was determined that the Rosa L. taxa contained low levels of lauric acid. In accordance with the results from the statistical analysis of the saturated fatty acid contents found, the saturated fatty acids varied according to the taxa and the difference between the taxa was statistically significant at the 5% level. When the descriptive statistics of the palmitic acid contents in the seeds of Rosa L. taxa were considered, the content of palmitic acid varied between 4.44-7.28% with an average of 5.50%, the stearic acid contents ranged between 1.15-4.80% and averaged at 2.70% (Table 2).

It was determined that R. pisiformis has the lowest palmitic acid content; while the R. montana subsp. woronovii taxa has the highest palmitic acid content. R. foetida has the lowest stearic acid content, and hybrid tea rose seeds have the highest stearic acid content.

In some studies on Rosa L. taxa, the palmitic acid values for seeds were found by Szentmihalyi et al. (2002) to be 7.87%, by Nowak (2005) at 3.05%, Machmudah et al. (2007) found 5.01%, and Kazaz et al. (2009) at 3.66%. The average palmitic acid values for the Rosa L. taxa in this study were found to be 5.50%, which is comparable to the literature findings. Considering the palmitic acid values of the rose taxa used in this research, it was found that they were high for the roses used for landscaping and in R. foetida species.

In some studies on Rosa L. taxa, the stearic acid values for the seeds were found by Szentmihalyi et al. (2002) at 3.18%, by Nowak (2005) at 1.84%, by Machmudah et al. (2007) at 2.72%, by Prescha et al. (2014) at 1.80%, and Turan et al. (2018) at 2.19% stearic acid. The average stearic acid values for the Rosa L. taxa examined in this study were found to be 2.70%, which is comparable to the literature.

It was determined that there are saturated fatty acids such as lauric acid, mystric acid, pentadecanoic acid, heptadecanoic acid, and behenic acid in the seeds of the taxa in question. A high amount of lauric acid content (0.27%) was found in the R. foetida taxa compared to other taxa, and the mystric acid content was found at a higher level (0.12%) in R.montana taxa compared to other taxa.

According to the results from the analysis of the unsaturated fatty acid contents in the seeds of the Rosa L. taxa with the data from 2021, oleic, linoleic, linolenic, palmitoleic, heptadecanoic, arachidic, eicosenoic and eicosapentanoic acid contents varied according to the taxa and the difference between the taxa was statistically significant (Table 3).

Linoleic acid (ω6) contents in the investigated rose taxa ranged from 41.63 to 50.11% with an average of 44.88%. Oleic acid (ω9) contents ranged from 20.80 to 30.27% with an average of 24.95%. Linolenic acid (ω3) contents in eicosenoic acid varied between 14.00 and 28.51%, with an average of 19.20%. Arachidic acid contents ranged from 0.75 to 1.63% and the average was 1.97%. Eicosenoic acid contents ranged between 0.13 and 0.65% with an average of 0.33%. Palmitoleic acid contents ranged from 0.08 to 0.60. The content of behenic acid was found to vary between 0.08 and 0.19%, which is 0.11% on average.

According to the data obtained, the lowest oleic acid content was determined in R. x hybrida, and the highest oleic acid content was found in R. foetida and ‘Yildiz’ seeds from 2021 (Table 4). As a result of the analysis, the lowest linoleic acid content was found in R. montana subsp. woronovii and R. heckeliana, and the highest linoleic acid content was found in R. canina and hybrid rose seeds. It was determined that R. canina ‘Yildiz’ contained the highest alpha-linolenic acid content and R. heckeliana species had the highest linolenic acid content.

Szentmihalyi et al. (2000), Nowak (2005), Ercisli (2007), Machmudah et al. (2007), Kazaz et al. (2009), Celik et al. (2010), Prescha et al. (2014), İlyasoğlu (2014), Turan et al. (2018), Kizil et al. (2018), Vasic et al. (2020) stated that the distribution of fatty acids is more important than the oil content in the seeds, and that rose/rosehip seeds are rich in unsaturated fatty acids and their fatty acid compositions consists of major linoleic, oleic, and alpha-linolenic acids. Considering the fatty acid values for the rose taxa used in the research, it was determined that the data obtained and the literature data were generally comparable.

In Aydın’s (2010) study, it was stated that the ideal omega-3/omega-6 ratio should be between 1 and 0.25, and that among these ratios, the anti-inflammatory, analgesic and blood thinning effects of the herbal product would be more effective. The ω-3/ω-6 values for olive oil and grape seed oils were found to be in these ranges. It was determined that R. canina ‘Yildiz’ and R. x hybrid taxa of Rosa L. taxa were close to this oil yield. The hybrid Chinese rose, which is used as a landscape rose and whose fruits were not evaluated, and the R. canina ‘Yildiz’ cultivar, were found to contain high rates of oleic acid, known as omega-9 fatty acid. These are promising results.

The contents of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) in the macro elements examined in the seed samples differed statistically from one another. Accordingly, the highest nitrogen content was found in the R. pisiformis staxa (Table 5).

It was determined that the iron (Fe), copper (Cu), zinc (Zn), manganese (Mn) and boron (B) contents in the micro elements examined in the seed samples statistically differed from one another by 5%. Accordingly, the highest iron content (73.26 ppm) was found in R. montana subsp. woronovii; the lowest iron content (30.70 ppm) was detected in the seeds of the R. canina ‘Yildiz’ taxa (Table 6).

Kazaz et al. (2009) determined the macro elements in R. canina seeds as 0.12% P, 0.32% K, 0.38% Ca, 0.09% Mg. According to the findings obtained in the study, the mean P values of 11 Rosa L. taxa were determined as 0.12% P and 0.31% K, and these two elements were found to be similar to the relevant literature. On the other hand, Ca and Mg values were found to be higher in the study. The iron, copper, zinc, manganese and boron contents in the seeds of R. canina were averaged and the taxa was also examined. They reached similar findings in the order of the mentioned micro elements and reported that there were higher mineral contents compared to the seeds of R. x damascena.

Ercisli (2007) and Kazaz et al. (2009) also found low Cu contents in the species. It was determined that the ‘Yildiz’ rosehip cultivar, which was examined within the scope of the research, contained higher levels of copper compared to these studies and other taxa. Szentmihályi et al. (2002) determined the average Fe content in the seeds of the R. canina taxa to be 20.15 ppm in their research. Ercişli (2007), Szentmihályi et al. (2002) and Kazaz et al. (2009) found zinc values between 3.69 and 14 ppm in their studies conducted on different rosehip genotypes. These researchers generally examined the taxa of R. canina and R. x damascena. It was concluded that they may be different species with high element contents apart from the commonly known taxa due to the different reasons for the genotype effect. For example, R. pisiformis seeds contain higher amounts of zinc and potassium. As a result of the research, it was found that the taxa examined had higher iron and zinc contents than this value. In light of this information, it can be said that the presence of some mineral substances in the seeds of Rosa L. taxa grown under similar greenhouse conditions is directly related to the genotypes, and the seed of the said taxa contains significant amounts of macro and micro nutrients.

The differences between the taxa in terms of the macro and micro element contents in both leaves and seeds show that the element intake of the taxa is under genotype control. As a matter of fact, there are findings in the literature that the plant element contents in the seeds of Rosa L. taxa differ from each other (Ercisli, 2007; Szentmihályi et al., 2002; Kazaz et al., 2009). The findings obtained for the seeds of the taxa also bring to mind the effect of antagonism, which is very important in plant nutrition. As a matter of fact, K and Ca and Mg often show antagonism. In this context, it can be said that the elements that are absorbed in high amounts from the soil accumulate in the seeds and that the antagonistic effects can also be seen in the seeds. As a result, it is thought that it is possible to use rose seeds in food and food additive sectors, as well as rosehip fruits, and to use the seeds in different production areas.