Carbotrap b

Inflorescence scent data collected in 2017 for the JOS and DAO populations (N_JOS = 34; N_DAO = 61) were obtained from Gfrerer et al. (2021) (link). In short, scent was collected on the first day of anthesis between 18:00 and 19:30, i.e., the time period of peak scent emission (Marotz-Clausen et al., 2018 (link)), by bagging each inflorescence in an oven bag (c. 30×12 cm; Toppits, Melitta, Germany) and collecting scent via dynamic headspace, following Marotz-Clausen et al. (2018) (link), for five minutes at 200 ml min^-1 with a vacuum pump (rotary vane pump G12/01 EB, Gardner Denver Austria GmbH, Vienna, Austria). Volatiles were trapped on a mixture of Tenax-TA (mesh 60–80) and Carbotrap B (mesh 20–40; 1.5 mg each; both Supelco, Taufkirchen, Germany), which was filled in quartz glass tubes (length: 2–3 cm; inner diameter: 2 mm). Samples from leaves and ambient air served as negative controls. Obtained scent samples were analysed by thermal desorption–gas chromatography/mass spectrometry (TD-20 coupled with QP2010 Ultra EI GC/MS, Shimadzu Corporation, Kyoto, Japan), and acquired data were analysed in GCMSolution v.4.41 (Gfrerer et al., 2021 (link)).

Floral volatiles were collected in the field using dynamic headspace methods described by Dötterl et al. [60 (link)]. Inflorescences with 5–20 open flowers were enclosed in oven bags (polyester; Toppits^®, Germany; 8 cm × 10 cm) for 30 min. The accumulated floral volatiles (floral headspace) were subsequently collected from the bag for 5 min or 10 min by pulling the air through an adsorbent trap using a membrane pump (G12/01 EB, Rietschle Thomas Inc., Puchheim, Germany) with a flow rate set to 200 mL/min). The adsorbent traps were made of quartz microvials (ChromatoProbe; Varian Inc., Palo Alto, CA, USA; 15 mm length; 2mm inner diameter; closed end cut open) filled with a mixture (1:1, v/v) of Tenax-TA (mesh 60–80) and Carbotrap B (mesh 20–40) (Supelco, Bellefonte, PA, USA). The microvials were plugged with glass wool from both ends to keep the Tenax-Carbotrap mixture in place. In addition, samples of ambient air were collected in order to distinguish between floral volatiles and those in surrounding air (see [22 (link)]).