## 3 Discussion
A similar trend was observed in our study, in which compounds of MWs higher than 100, such as acetovanillone, benzyl alcohol, camphor, _trans_-caryophyllene, 1,8-cineo, \(\alpha\)-copaene, decanal, dihydromycenol, _cis_-\(\alpha\)-irone, limonene, linanool, nervl formate, nonanal, perilla aldehyde, 2-phenylethylanol, and undecan-2-one, were (in most cases) extracted in greater amounts using PDMS/DVB fiber. On the other hand, compounds with MWs up to 100 and/or with the lowest RIs (<900), such as acetic acid, acetoin, butan-2,3-diol, ethanol, furfural, and hexanal, were (in most cases) better extracted by the less polar DVB/CAR/PDMS fiber (Supplementary Table S1). Considering that the present study is the first to report the VOC compositions of _I. pseudopallida_, _I. illyrica_, and _I. adriatica_, there is a lack of literature data to compare our results with other studies. However, some studies have reported VOC compositions of flowers of other _Iris_ species [25; 59]. For example, according to [PERSON] et al. [25], an HS-SPME/GC-MS analysis of floral scent profiles revealed that, out of 27 analyzed accessions of three bearded iris species, the alcohols constituted the most predominant components in _7 I. germatica_ and _2 I. punilla_ cultivars. The irises included in our study are also representatives of bearded irises (subgenus _Iris_, section _Iris_), which are characterized by bearded outer petals. Hereby, _I. pseudopallida_ and _I. illyrica_ are closely related tall bearded taxa from the _I. pallida_ complex, while _I. adriatica_ is a dwarf bearded taxon from the _I. punila_ complex [27; 60]. This fact may explain why, in the observed results of PCA analyses, the prior two taxa were often grouped together, while _I. adriatica_ was separated from them. The main individual compound identified in all investigated samples, except for _I. pseudopallida_ D, which was extracted using HS-SPME, was perilla aldehyde. Perilla aldehyde is a compound characteristic of _Perilla frutescens_ (L.) Britt. EO and one of the major contributors to its insecticidal and repellent activity [61]. This compound was better extracted using the PDMS/DVB fiber, same as some other aldehydes, such as nonanal and decanal, and sesquiterpene hydrocarbons such as _trans_-caryophyllene and \(\alpha\)-copaene. Nonanal is another compound that was found in the same five samples. Nonjaldehyde (nonanal) has been recently reported as a common compound in the floral scents of _I. uniflora_ Pall. [PERSON], _I. triphylifolia_ [PERSON], and _I. sanguinea_ Hornem., found after HS-SPME using DVB/CAR/PDMS fiber [59]. All investigated taxa also contained _trans_-caryophyllene (2.86%) was one of the major sesquiterpene hydrocarbons of EO extracted from aerial fresh blooms of _I. nigricans_ during the pre-flowering stage [29]. \(\alpha\)-Copaene was also detected in all harvested samples of _I. pseudopallida_ and _I. ilyrica_, but not in _I. adriatica_, with the concentrations being greater (0.98-5.14% on both fibers) than what was previously reported for the EO extracted through steam distillation from rhizores of _I. carthuliniae_ and _I. medwedewii_ Fomin (0.2% and 0.1%) [43]. One of the main individual compounds in all three _I. pseudopallida_ populations and both _I. ilyrica_ populations (1.30-9.47% on both fibers), and which was also found in _I. adriatica_, was 6-methylhept-5-en-2-one. Based on previous findings, 6-methylhept-5-en-2-one can be produced during the oxidation reaction of lycopene [62]. Our results were similar to the results obtained for the EOs obtained by hydrodistillation from air-dried flowers and rhizomes of _I. persica_ (7.1% and 11.4%) [21], and _I. pseudacorus_ L. (11%) EOs, isolated from the flowers by microdistillation, as well as _I. kerneriana_ flowers and rhizomes (7.1% and 7.7%) [20]. Limonene and 1.8-cineole (3.52-4.79% and 2.38-3.82%), along with furfural (1.80-7.91%), were among the primary individual compounds identified for _I. adriatica_.