A molecular cytogenetic analysis of chromosome behavior in Lilium ...

U-type exchanges in Lilium hybridsTable 4.1. Chromosome associations and segregation abnormalities during meiosis in 13 LA hybridsChromosome pairing BridgeHybridformation# of cellsgenotypeRange of Average frequency atanalyzednumberbivalents bivalents anaphase IRemarks*(%)006001-6 256 9-12 11.2 17 Sporadic multivalents006001-9 228 3-11 7.6 6006001-13 132 6-11 8.7 1Sporadic nonhomologous/homoeologouspairing006001-16 143 5-10 6.2 11006001-17 139 4-11 7.2 3006001-36 141 2-9 5.4 7006001-42 133 3-9 4.2 5006001-72 136 4-7 5.6 6006001-80 129 3-9 3.9 2006001-88 126 7-12 10.7 9006001-97 135 4-10 6.2 0041501 133 10-12 10.8 4041502 124 4-10 7.3 0*Bridge information was scored according to the anaphase I and telophase I pollen mothercellsResultsChromosome breakage at metaphase IChromosome association was observed at metaphase I during meiosis using GISH. In thesehybrids, 120 to 260 pollen mother cells were observed and analysed. The main character inthese 13 interspecific hybrids is the occurrence of bivalents involving homoeologouschromosomes, as well as univalent with failed association. Meanwhile, few quadrivalents,trivalents and bivalents involving non-homologous association between two Asiaticchromosomes were also detected, indicating the existence of chromosome translocation.Furthermore, chromatid breakage was also sporadically observed at metaphase I stage. In oneof the pollen mother cells with 12 bivalents, an Asiatic chromosome in one of the bivalents51