Cytogenetic analysis of progeny derived from allotriploid inter-specific hybrids of Lilium

Abstract

The allotriploid cultivar‘Angela North’(2n = 3x = 36) possessing one genome of Lilium lankongense Franchet and two genomes of Asiatic hybrids (AH), and allotriploid cultivars from LAA group containing one genome of L. longiflorum Thunberg and two genomes of AH were backcrossed with diploid (2n = 2x = 24) and tetraploid (2n = 4x = 48) cultivars of lilies from AH group. Progeny was received only by cultivating isolated embryos on MS media. LAA cultivars for backcrossing were used as female and male, however, cv. ‘Angela North’ possessed only female fertility. More than half of progeny received after crossing the allotriploid cv.‘Angela North’ with diploid or tetraploid AH possessed a diploid set of chromosomes and others were aneuploid with a chromosome number near to diploid or triploid. The number of chromosomes in progenies derived after pollination of LAA cultivars with tetraploid AH ranged from diploid to nearly pentaploid. No viable progeny was received after pollination of LA by diploid and tetraploid AH by LAA. When male fertile LAA cultivars were used to pollinate diploid AH, mainly diploid progeny were received. It shows that viable pollen of allotriploid LAA cultivars possesses a balanced haploid set of chromosomes. It looks likely that diploid progeny derived after pollination of allotriploid hybrids with tetraploid AH are apomictic. If diploid progeny derived from allotriploids possess recombinant chromosomes and restored fertility, they should be valuable in breeding programs for introgression of traits from L. lankongense and L. longiflorum in Asiatic hybrids. Keywords: Lilium lankongense, L. longiflorum, inter-specific hybridization, allotriploid, apomixis