Inheritance of calyx shape in the genus Origanum (Lamiaceae)

Five different traits responsible for calyx shape within the genus Origanum were found to be determined by five independent genes. The five traits are bell‐shaped vs. tubular‐shaped calyx, angular vs. round teeth on the upper lip, entire vs. denticulate upper lip, fully developed vs. reduced lower lip and entire vs. denticulate lower lip. The simple Mendelian inheritance of most traits for calyx shape could be used to identify hybrids between Origanum species arising from open‐pollinated plants and so avoid tedious artificial pollination resulting from small flower sizes in Origanum. Such hybrids are interesting base material for character transfer (e.g. winter hardiness or seed size) between economically important species.