Introgressione criptica di DNA parentale in linee di frumento derivate da ibridazione intergenerica fra Triticum aestivum e Dasypyrum villosum

Abstract

Cytogenetic and DNA molecular analyses have been carried out in three wheat inbred lines (CS V58, CS V59 and CS V60), derived from Triticum aestivum cv. ‘Chinese Spring’ (CS) Dasypyrum villosum (Dv) intergeneric hybridization, which showed several Dv-specific phenotypic characters. All lines were found to share with CS the number (2n=42) and structure of the chromosomes and chromatin from Dv was apparently not added to their complement. However, Feulgen/DNA cytophotometry showed that there was more nuclear DNA in the lines than in the parental wheat (by 1.85%, 2.76% and 1.26% in CS V58, CVS V59 and CS V60, respectively). AFLP analysis of genomic DNA from the lines, CS and Dv detected a total of 120 polymorphic bands, 7 of which (5.8%) were present in both the lines and Dv but absent in CS. PCR amplification using specific primers revealed, in the genome of the lines, Dv alleles and not CS alleles at two loci (Vrn-A1 and Vrn-B3). These results indicate cryptic introgression of Dv DNA sequences into the genome of the lines. Some implications of this finding are briefly discussed.