Comparison of the Giemsa C-banded karyotypes of Dasy-pyrum villosum (2x) and D. breviaristatum (4x) from Greece

Abstract

The karyotypes of one plant of Dasypyrum villosum (2n = 2x= 14), of two plants of D. breviaristanam (2n = 4x = 28) and an intraspecific hybrid, and of a D. breviaristatum x D. villosum hybrid were studied by Giemsa C-banding of somatic metaphases and Giemsa and AgNO3-staining of interphases. The karyo-type of D. villosum had 10 metacentrics, 2 submetacentries, and 2 metacentric SAT-chromosomes with small satellites. The C-banding patlerns were characterized by conspicuous distal and/or terminal, in some cases double bands in most chromosome arms, and inconspicuous centromeric and juxtacentromeric bands, D. breviaristatum had two cytotypes. one with 20 metacentrics, 2 submetacentrics. and 6 metacentric SAT-chromosomes, 4 similar ones with Large and 2 with small satellites. In the other cytotype the latter pair was replaced by a pair without visible satellites. The banding patterns had most conspicuous bands at centromeric or proximal positions in about half the chromosomes. Banding pattern polymorphism was observed in both species in agreement with their outbreeding nature. Reliable identification of homology was only possible in D. villosum. In D. breviaristatum it was prevented by the overall similarily of banding patterns and chromosome morphology, but genomic relationships of chromosomes was established in the intraspecific hybrid. The C-banded karyolype of D. breviaristatum did not support an autoploid origin based on D. villosum.