Chromosomal variation in Crocus vernus Hill (Iridaceae) investigated by in situ hybridization of rDNA and a tandemly repeated sequence
2000
Frello, S. | Heslop-Harrison, J.S.
The physical localization of three tandemly-organized repetitive DNA sequences was investigated byin situ hybridization to metaphase chromosomes of 11 Crocus vernus accessions. The sequences included were the 18S–25S rDNA, the 5S rDNA and a tandemly-repeated sequence cloned from C. vernus(clone pCvKB8). Ten 2n = 8 karyotypes from accessions ranging across the Alps and the Pyrenees could be interpreted as variations of a standard karyotype. Polymorphisms were found involving size of the satellite chromosomes, extra 5S rDNA sites, and extensive differences in size and number of pCvKB8 loci. The 2 n = 16 type did not correspond to any possible tetraploid derived from the 2 n = 8 types.
显示更多 [+] 显示较少 [-]