Sponge and dough bread making: genetic and phenotypic relationships with wheat quality traits.

The genetic and phenotypic relationships among wheat quality predictors and sponge and dough bread making were evaluated in a population derived from a cross between an Australian cultivar 'Chara' and a Canadian cultivar 'Glenlea'. The genetic correlation across sites for sponge and dough loaf volume was high; however, phenotypic correlations across sites for loaf volume were relatively low compared with rheological tests. The large difference between sites was most likely due to temperature differences during grain development reflected in a decrease in the percentage of unextractable polymeric protein and mixing time.

Comparative field performance over 3 years and two sites of transgenic wheat lines expressing HMW subunit transgenes.

A series of transgenic wheat lines expressing additional high molecular weight (HMW) subunit genes and the corresponding control lines were grown in replicate field trials at two UK sites (Rothamsted Research, approximately 50 km north of London and Long Ashton, near Bristol) over 3 years (1998, 1999, 2000), with successive generations of the transgenic lines (T3, T4, T5) being planted. Four plots from each site were used to determine grain dry weight, grain nitrogen, dough strength (measured as peak resistance by Mixograph analysis) and the expression levels of the endogenous and "added" subunits. Detailed statistical analyses showed that the transgenic and non-transgenic lines did not differ in terms of stability of HMW subunit gene expression or in stability of grain nitrogen, dry weight or dough strength, either between the 3 years or between sites and plots.