Suspensions of intact cell nuclei were prepared according to Vrána et al. (2016). Briefly, mature dry seeds of subterranean clover (Trifolium subterraneum L.) cv. Daliak (approx. 20 g) were germinated on moistened paper towels in the dark at 25° ± 0.5 °C until roots achieved 2–3 cm in length. Roots were cut to 1 cm from the apex and transferred into 25 mL formaldehyde fixative (2% v/v) for 20 min at 5 °C, followed by three 5‐min washes in Tris buffer. Finally, the root tips (approx. 40) were cut, transferred into 1 mL IB buffer (Šimková et al., 2003) and homogenized using a mechanical homogenizer (blender) at 13 000 RPM for 18 s. The crude homogenate was filtered through 50‐μm (pore size) nylon mesh and stained with DAPI (2 μg/mL final concentration). A total of fifteen samples were prepared.