http://http://dspace.unitus.it:80 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. 2013-05-23T20:15:58Z http://hdl.handle.net/2067/2197 Title: Development of valuable wheat inbred lines through the introduction of Dasypyrum villosum germplasm in their pedigree Authors: De Pace, Ciro; Vaccino, Patrizia; Caceres, Maria Eugenia; Corbellini, Maria Abstract: Selection of improved stable wheat inbred lines for low input production systems was achieved through the relevant combination of wheat and Dasypyrum villosum (Dv) germplasm using two approaches: (1) a re-evaluation of a tri-parental species breeding scheme, and (2) a modified bulk-breeding method. Both methods optimized selection outcome. The first breeding method was based on the synthesis of a T. turgidum var durum Dv hexaploid amphiploid, and crossing of that amphiploid to a bread wheat cultivar. The second breeding method was developed by bulk harvesting seeds from F1 and F2 from each biparental combination involving commercial wheat cultivars and wheat introgression breeding lines (IBLs) containing various amount of chromatin from Dv. In the first case, the M V amphiploid displayed typical adaptive traits of Dv such as high resistance to diseases and heading earliness, and the further crossing of the amphiploid to Triticum aestivum cv Chinese Spring (CS) provided wheat breeeding lines showing additional enhancements for grain size and grain end-use quality. GISH analyses revealed that Dv chromatin introgression occurred in some of them, coupled to chromosome-arm exchanges. Interestingly, three of the selected lines, after two years of genetic analyses and low-input field tests, showed dominance and genetic stability of the adaptive traits. In the second case, the F1s expressed the ‘useful’ Dv genes inherited from the IBLs, providing strong evidence that the Dv genes for trait enhancements are expressed not only in CS but also in ‘elite’ wheat genetic background. The F2 progenies displayed wide segregation offering ample opportunity for selecting the desired combination of the ‘elite’ traits with the traits expressed by the ‘useful’ Dv genes inherited through the IBLs. 2010-12-31T23:00:00Z http://hdl.handle.net/2067/1763 Title: Flowering earliness in wheat inbred breeding lines derived from T. aestivum ‘Chinese Spring’ x Dasypyrum villosum hybridization is not related to allelic variation at the vernalization loci VRN-A1, VRN-B1, and VRN-D1 Authors: Caceres, Maria Eugenia; Vaccino, Patrizia; Corbellini, Maria; Cionini, Pier Giorgio; Sarri, Vania; Polizzi, Enza; Vittori, Doriano; De Pace, Ciro Abstract: Substantial cryptic chromosome mutations or recombinations or gene mutations have occurred during the earlier generations following the hybridization T. aestivum “Chinese Spring” (CS) x Dasypyrum villosum event. Those genomic modifications were transmitted to the progeny plants, from which wheat introgression breeding lines (IBL) were derived. One of the mutations might have affected a flowering-promoting gene at a locus different from VRN-1, causing (under nonvernalizing condition and 13-14-hour daylength) the IBL “CSxV59” and the F1 hybrids “CSxV59 x cv Salgemma" and “CSxV59 x cv Isengrain” to start anthesis in less than 50 days from sowing compared to CS and to the two parental winter bread wheat cv Salgemma and cv Isengrain, which flowered about 150 days later. 2007-12-31T23:00:00Z http://hdl.handle.net/2067/2203 Title: Introgressione criptica di DNA parentale in linee di frumento derivate da ibridazione intergenerica fra Triticum aestivum e Dasypyrum villosum Authors: Caceres, Maria Eugenia; Vaccino, Patrizia; Ceccarelli, Marilena; Sarri, Vania; Polizzi, Enza; De Pace, Ciro; Cionini, Pier Giorgio 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. 2010-12-31T23:00:00Z http://hdl.handle.net/2067/2202 Title: Citogenetica di ibridi fra Triticum aestivum e Dasypyrum villosum e di linee da essi derivate Authors: Caceres, Maria Eugenia; Ceccarelli, Marilena; De Pace, Ciro; Cionini, Pier Giorgio Abstract: In the course of a research aimed at the genetic improvement of wheat through intergeneric hybridization, 24 inbred breeding lines obtained by the hybridization of Triticum aestivum cv. ‘Chinese Spring’ (CS) or T. turgidum ssp. durum cv. ‘Modoc’ followed by backcross to CS have been characterized cytogenetically. Some lines were found to have the same karyotype as CS. In other lines, karyological events such as chromosome addictions, chromosome substitutions, recombinations between parental genomes or between the homoeologous genomes of wheat were observed. These findings, which were in part unexpected and even surprising, show that a careful cytogenetic characterization of wheat hybrids is necessary to understand factors and mechanisms that play a role in determining the structure of their karyotype, and then to choose strategies for the genetic improvement of wheat by interspecific and/or intergeneric hybridization. 2010-12-31T23:00:00Z