Genomic variation of new cultivars selected from distant hybridization in Lilium

With 1 figure and 1 table Abstract One of the main trends in Lilium breeding is to combine horticultural traits of Asiatic (AA), Longiflorum (LL), Oriental (OO) and Trumpet (TT) lilies. We used genomic in situ hybridization to examine the genomic variation of 19 new cultivars, bred by hybridization between different lily groups, to determine how the cultivars arose. Two of them are diploid (2n = 2x = 24), selected from F 1 OT hybrids, 16 are allotriploid (2n = 3x = 36), mainly from 2n gametes and less possibly from diploid × amphidiploid crosses; and one cultivar was allotetraploid with three L‐genomes and one O‐genome. Our results indicate that allotriploid breeding is a future trend for new cultivars in Lilium and that most of the allotriploid lily cultivars originate from 2n gametes produced by F 1 distant hybrids.