Dough mixing properties are important in determining wheat processing and end-use quality. The Reomixer is a mixograph type device which provides mixing curves, described in detail by a total of 17 parameters. We analyzed the Reomixer mixing parameters of 26 breeding lines grown in 2007, in four contrasting environments (with and without Nitrogen fertilization, under water stress or irrigated). Using these data, we attempted to condense the information by identifying the most suitable parameters for use in a breeding program. We used the following criteria: high reproducibility (minimum coefficient of variation among repetitions), high genotype influence (i.e. high heritability), larger amount of information about overall variation of the other mixing parameters and complementarity of information (low correlation with other selected parameters). Mixing parameters varied widely for all criteria and no one parameter was best for all of them. Based on average performance we selected: “initial slope”, “peak time”, “peak height”, “end width” and “breakdown”, as having better ranking for the first three criteria and being less correlated between themselves than other mixing parameters. The five selected parameters cover all phases of dough development and describe all basic rheological aspects of mixing properties.
Authors:A. Giura, L. Conţescu, P. Mustăţea, G. Ittu, and N. Săulescu
Grain protein concentration is a major factor in determining bread-making quality of wheat. We studied the effect of chromosome 7B of the high protein line F26–70 on protein content, yield and heading date, by testing 45 recombinant substitution lines derived from the cross Favorit//Favorit/F26-70(7B) in field trials, in 2005–2007. In 2006 and 2007 the lines were tested with and without nitrogen fertilization. Genes located on chromosome 7B of line F26–70 had significant effects on grain protein concentration and on heading date of recombinant substitution lines, but not on grain yield. In the conditions of our trials, protein content was not negatively associated with grain yield. Association of high protein content with earliness was significant in one year out of three. The interaction between RSLs and nitrogen fertilization was not significant, suggesting that the high protein gene(s) on chromosome 7B might be also useful at low nitrogen availability. Segregation of RSLs for grain protein concentration suggests a small number of genes, possibly one gene, responsible for the variation caused by chromosome 7B. We conclude that the high protein gene(s) on chromosome 7B might be potentially interesting for breeding.
Authors:M. Ciuca, D. Cristina, A.G. Turcu, E.L. Contescu, V. Ionescu, and N.N. Saulescu
Wheat continues to be one of the most cultivated cereals in the world, and also in Romania. Leaf rust caused by Puccinia triticina reduces the wheat yield and grains quality worldwide. In the context of climate change, leaf rust has become a more important problem for both wheat growers and breeders in our country. Use of genetic resources, carrying rust resistance genes, play an important role in breeding programs leading to resistant varieties, which can have positive impact on environment and economy. Therefore, the identification of resistance genes in modern wheat cultivars and breeding lines, and then selection of the best resistance genes combination(s) are the first steps for a successful breeding program. At present, one of the best known and studied adult plant leaf rust resistance gene is Lr34 that contributes significantly to durable leaf rust resistance. The functional markers that enable early detection of this gene are a major advantage in the wheat breeding.
The aim of this study was to evaluate the presence of the slow rusting resistance gene Lr34 in Romanian wheat germplasm, using cssfr4 and cssfr5 molecular markers. Screening of 47 winter bread wheat cultivars and 47 breeding lines with these markers showed the presence of the Lr34 resistant haplotype in 62% (homozygous genotypes) of the total genotypes. A high frequency (79%) of Lr34 resistance allele was found among 47 breeding lines, suggesting that maintenance of a high frequency of this allele represents a real advantage for the development of adult plant resistance in Romanian breeding programs.