C-banding polymorphism and the analysis of nucleolar activity in Dasypyrum villosum (L.) Candargy, its added chromosomes to hexaploid wheat and the amphiploid Triticum dicoccum — D. villosum

Abstract

C-banding patterns and nucleolar activity were analyzed in Dasypyrum villosum, its added chromosomes to hexaploid wheat and the hexaploid amphiploid Triticum dicoccum-D. villosum. Two different populations of the allogamous species D. villosum (2n= 14, VV) from Greece and Italy were analyzed showing a similar polymorphism for C-banding pattern. Six of the seven addition lines were identified by their characteristic C-banding pattern. No polymorphism between both members of each added alien chromosome was found. Furthermore, nucleolar activity and competition were studied by using silver staining procedure. In D. villosum only one chromosome pair, A, was found to be responsible for organizing nucleoli. The results obtained in the amphiploid and in the addition lines demonstrate that nucleolar activity is restricted to SAT-chromosomes 1B and 6B of wheat, while those of D. villosum remain inactive.

Molecular and chromosomal characterization of repeated and single-copy DNA sequences in the genome of Dasypyrum villosum

“…Clear labelling over the background was not observed at or near the centromere in any chromosome. Apart from the nonlabelled pair and the centromeric or pericentromeric regions, the distribution of silver grains was similar to that of heterocrhomatin as disclosed after C-banding (DONG FRIEBE et al 1987). The same labelling pattern over the V chromosome was observed in the hexaploid amphiploid D. villosum x Triticum turgidum var.…”

First cytogenetic investigation in populations of , endemic from La Réunion island, with reference to

“…Moreover, all the individuals may not be homozygous for transloeations and intra-individual variations between cells are likely. Such variations of GC-banding pattern have been reported in other species by Friebe, Cermeno and Zeller (1987), who cou1d not propose any explanation for their origin. Deum1ing and Greilhuber (1982) stated that the size of heterochromatin bands could vary within a species, and even between homologues in one individual and invoked selection of some satellite sequences without offering any putative function.…”

Nuclear DNA content, chromatin organization and chromosome banding in brown and yellow seeds of Dasypyrum villosum (L.) P. Candargy

“…Metaphase chromosomes The general karyotype of D. villosum is analogous to the one reported by Gill (1981), Friebe et al (1987), Grilli et al (1988) and Linde-Laursen & Frederiksen (1991). The techniques of differential chromosome staining allowed the identification of each pair of chromosomes.…”

“…The long arm is characterized by a large subtelomeric C-band which is clearly seen after H33258 staining in both yellow and brown types. This chromosome resembles the D (4H) of Friebe et al (1987). Chromosome iii.…”

“…The long arm is quite constant showing two thin telomeric C-bands also observed after H33258 staining. This chromosome resembles A (1H) of Friebe et al (1987). …”