Chromosome relationships among 13 species and one variety of Lachenalia (Liliaceae) with the chromosome numbers of 2n=14 and 16 detected by FISH using 5S rDNA and 18S rDNA probes and DAPI staining

Abstract

The structural comparison of somatic chromosomes of 13 species and one variety of Lachenalia (Liliaceae) that contained the chromosome numbers either of 2n=14 or 2n=16 (the basic chromosome numbers may be x=7 or x=8) was performed by DAPI staining and fluorescence in situ hybridization (FISH) using 5S rDNA and 18S rDNA probes. The five taxa which had the chromosome number of 2n=16 (x=8) displayed similar characters and close relationships to each other. Eight species and one variety which had the chromosome number of 2n=14 (x=7) showed a variety of patterns. The cases were suggested as traces of additions to the 18S rDNA region, translocations of chromosomes and hereditary exchanges among the taxa with x=7 and a taxa with x=8. It was suggested that the chromosome diversity in Lachenalia, especially in the taxa of basic chromosome number of x=7, was resulting a speciation reflected by hereditary influences between the taxa which had other patterns of chromosome structures.