Study On The Crossing Compatibility Of 4 Lilies And Hybrid Identification

Lily is a kind of significant economic flower and belong to the genus Lilium in the family Liliaceae.The main means of lily breeding is to breed new species through the germplasm innovation.The currently popular lily species all originate from interspecific crosses.However,some important wild resources in China,such as L.leucanthum Baker and L.davidii var.unicolor,have not been well exploited,so in this research,we used conventional pollination and cut style pollination to realize the crosses of L.regale Wilson and ‘Black Magic’,L.regale Wilson and L.davidii var.unicolor,L.regale Wilson and L.leucanthum Baker,then studied their hybridization behavior.Using Fluorescence in situ hybridization(FISH),Genome fluorescence in situ hybridization(GISH),and randomly amplified polymorphic DNA analysis(RAPD)to identify the authenticity of the hybrids,and the results were as follows:(1)The cross of L.regale Wilson and ‘Black Magic’: Since this was an intersection cross and the number of flowers was limited,only cut style pollination was used in this study based on previous hybridization experience.16 flowers of L.regale Wilson as females were crossed with ‘Black Magic’ and a total of 6 fruits were obtained.6 seedlings were obtained after performing embryo rescue.FISH and GISH were used to identify the authenticity of the hybrids,and the results showed that the seedlings obtained from L.regale Wilson × ‘Black Magic’ were all true distant hybrid F1 generation,and the flower color inherited the special black of ‘Black Magic’.The results of pollen germination fertility assay showed the sterility of the F1 generation.(2)The cross of L.regale Wilson and L.davidii var.unicolor: Since this was an intersection cross and the number of flowers was limited,only cut style pollination was used in this study based on previous hybridization experience.2 flowers of L.regale Wilson as females were crossed with L.davidii var.unicolor and a total of 2 fruits were obtained.80 seedlings were obtained after performing embryo rescue.FISH and GISH were used to identify the authenticity of the hybrids,the results showed that the genomes of L.regale Wilson and L.davidii var.unicolor could be clearly distinguished,indicating that the seedlings obtained were all true distant hybrid F1 generation with yellow flower color.The results of pollen germination fertility assay showed the sterility of the F1 generation.(3)The cross of L.regale Wilson and L.leucanthum Baker: With L.leucanthum Baker as female and L.regale Wilson as male,5 flowers were conventionally pollinated,and 5 fruits were obtained,and 80 seedlings were grown by embryo rescue;5 flowers were pollinated by cut style,and 4 fruits were obtained,and 32 seedlings were grown by embryo rescue.Neither GISH nor FISH could distinguish the genomes of L.regale Wilson from L.leucanthum Baker.Therefore,molecular marker identification using RAPD showed that most of the bands were similar except for a few bands that were specific to the species,indicating that L.regale Wilson and L.leucanthum Baker are closely related.Nevertheless,the RAPD results indicated that the progeny obtained from their forward and backward crosses were indeed hybrids.In conclusion,L.regale Wilson and L.leucanthum Baker are closely related,and the present results are consistent with the general classification.The crosses between them belong to intra-section crosses.The results of crosses between L.regale Wilson,‘Black Magic’ and L.davidii var.unicolor support that L.regale Wilson belongs to different groups from ‘Black Magic’ and L.davidii var.unicolor.‘Black Magic’ is a species bred through intra-section crosses of Asiatic,L.davidii var.unicolor is breeding resource of Asiatic.The crosses of L.regale Wilson with ‘Black Magic’ and L.davidii var.unicolor belong to intersection crosses.The results of this study identify the basis for breeding new intersection species(TA).