Genomic in situ hybridization (GISH) analysis of intergeneric hybrids in Colchicaceae

Some intergeneric hybrids produced by the crosses among several colchicaceous ornamentals, Gloriosasuperba ‘Lutea’ (2n = 2x = 22), G. ‘Marron Gold’ (2n = 4x = 44), G. ‘Verschild’ (2n = 7x = 77), Littoniamodesta Hook. (2n = 2x = 22), and Sandersonia aurantiaca Hook. (2n = 2x = 24), were subjected to genomic in situ hybridization (GISH) analysis in order to clarify their genome constitutions. Chromosome preparation was made from root tip cells of L. modesta × G. superba ‘Lutea’, L. modesta × S. aurantiaca, S. aurantiaca × G. superba ‘Lutea’, L. modesta × G. ‘Marron Gold’, S. aurantiaca × G. ‘Marron Gold’ and G. ‘Verschild’ × S. aurantiaca. Total DNA of one parent was labeled with digoxigenin or biotin and used as probe, and chromosomes were counterstained with 4′-6-diamidono-2-phenylindole (DAPI). For all the nine intergeneric hybrids, chromosomes from each parent could be clearly distinguished by GISH analysis. Thus GISH analysis is a powerful tool for identifying the genome constitution of intergeneric hybrids in colchicaceous ornamentals. The results obtained by GISH analysis study may be important for further progress in breeding of colchicaceous ornamentals.