Soft wheat (Triticum aestivum L.) quality tests (milling and baking quality) and starch characteristics (amylose concentration, X-ray diffractograms, thermal properties and pasting properties) were determined for eight granule-bound starch synthase (GBSS: waxy protein) genotypes in a soft wheat background. Lines carrying two null alleles showed reduced amylose concentrations relative to those of single null and wild-type lines. Milling and baking quality traits were clearly different between waxy (triple null) and the other genotypes. Waxy lines showed the highest alkaline water retention (AWRC) capacity; even though, the protein concentration was not signi®cantly different from some double null and single null lines. The typical A-type patterns of X-ray diffractograms were observed for all starches. Waxy starch showed higher crystallinity than non-waxy starches. Analysis by Rapid Viscoanalyser (RVA) showed distinctive differences among the eight genotypes. Waxy starches showed higher peak viscosity, lower peak temperature and shorter peak time than those of all other genotypes. The results suggest that baking quality of waxy wheat can not be predicted by either AWRC or protein concentration. The interactions based on biochemical analysis between protein and other fractions (amylose and amylopectin, damaged starch) of partially and fully waxy wheat¯ours must be assessed before baking quality can be predicted. Furthermore, waxy wheat may not be suitable for current application of soft wheat products; however, distinct properties of waxy starch may open the possibility of commercial use in novel applications. Also, double null and single null genotypes may be a good source of variation for speci®c end-use products.

The confounding effect of wheat (Triticum aestivum L.) genetic background has been addressed as the major factor in inconsistent agronomic performances of 1RS translocation. The objective of this study was to test the effects of centric translocations of chromosome 1 in various rye (Secale cereal L.) sources on agronomic performance of wheat grown in humid southeastern conditions in North America. Various 1R substitution, 1RS translocation, and 1RL translocation lines in ‘Pavon 76’ were evaluated for agronomic performance. The 1RS translocation line was most favorable for agronomic performance when compared with those of substitution, 1RL translocation, and controls. The 1RS significantly increased grain yield. However, the effect of source of rye chromatin was greater than its position effect in wheat genome. Among translocation lines, those with 1RS derived from ‘E12165’ (CIMMYT) and ‘Amigo’ induced higher mean grain yield and T1DL·1RS derived from ‘BH1146/Blanco rye’ had the lowest grain yield. The mean grain yield of 1RL translocation lines was lower than that of 1R substitution. Thus, selection of 1RS source is important in producing constantly higher grain yield in 1RS translocation lines. Genetic recombination among different 1RS may also be used to create more genetic variation.