Application Of FISH In Different Ploidy Levels Cross-breeding Of Lily

Because of various ploidy levels,lily cultivars are good materials for studying the ploidy cross-breeding.The aims of the study were to research the relationship between lily crossbreeding affinity and ploidy level,to identify the hybrids,to explore the distribution of 45S rDNA on the chromosomes in Asiatic lily.The ploidy level was investigated,and interploid crossing was made by conventional pollination technique,furthemore the crossbreeding affinity was evaluated.The karyotype and fluorescence in situ hybridization with 45S rDNA probe were applied.The main results were shown as follows:1.21 crossing were conducted between Asiatic Lily with different ploidy levels,the results showed that the interploidy hybridization between diploid and tetraploid lilies was not as successful as intraploidy hybridization.Regardless of male sterility,triploid lilies could be used as female parents in the hybridization which the progenies were aneuploidy.3xx4x crosses could be cultured more successfully than 3x×2x crosses.2.The progenies of 2x x 2x,4x x 4x and 2x x 4x crosses were diploid,tetraploid and triploid respectively.The progenies of 3x x 4x crosses mostly were aneuploidy,with chromosome numbers as follows:'Navona' as female parent ranged from 36 to 47;'Freya' as female parent ranged from 40 to 60.3.Among the Asiatic lily cultivars,'Renoir' and 'Gironde' were diploid;'Navona' was triploid;'Detroit','Tresor' and 'Loreto' were tetraploid.LA hybrid 'Freya' was triploid.The karyotype of'Renoir','Gironde' and 'Freya' were 3A;'Navona','Detroit','Tresor' and 'Loreto' were 3B.The asymmetry indexes of LA hybrids was higher than Asiatic hybrids,the evolution degree was LA hybrids>Asiatic hybrids.4.There were 6?16 signal sites of 45S rDNA on lily cultivars,and normally the sites were not in pairs.The chromosomal compositon of different cultivars were not same,as well as some homologous chromosomes.45S rDNA distributed variably on chromosome 1,2,3,5,6,8,10 and 11 among Asiatic hybrids.Chromosome 1 had invariable sites of 45S rDNA in all Asiatic hybrids,which could be considered as the characteristic of Asiatic hybrids.LA hybrid 'Freya' had two sites of 45S rDNA on one homologous chromosome 11,and also it could be found in the progenies.5.The karyotype and fluorescence in situ hybridization with 45S rDNA as probe were applied to identify the different genotypes of 9 hybrids.Typical chromosomes with parental signal sites could be observed in all the genotypes of hybrids,it was confirmed that all the hybrids were true.The chromosomes of different genotypes varied.