Extensive chromosome rearrangements induced by γ-rays irradiation in lily mutant ‘Menglina Leddy’

The ‘Menglina Leddy’ lily cultivar was selected from the Lilium longiflorum Thunb. ‘White Fox’ γ-rays irradiation line. It produces much less pollen than ‘White Fox’ but has similar morphology traits. In order to reveal the effects of gamma irradiations on the chromosomes, mitosis, and meiosis in ‘Menglina Leddy’ cells were investigated by fluorescence in situ hybridization using rDNA and telomeric repeat probes. Although both ‘Menglina Leddy’ and ‘White Fox’ had 24 chromosomes, a considerable amount of chromosomal breaking and rejoining were detected in the former. A super long and two super small chromosomes appeared in all the ‘Menglina Leddy’ cells. Meiotic abnormalities occurred at each separation stage. Chromosomes pairing configuration showed that complex recombination had happened in ‘Menglina Leddy’. The super long chromosome was a Robertsonian translocation product composed of two non-homologous long arms. The chromosome deletions and recombinations did not affect the main ornamental traits, but allowed it to acquire the characteristic of less pollen.