| On the intraspecific variability of baking quality
components in Einkorn-wheats, Aegilops speltoides and Aegilops
squarrosa D. METTIN Institut fuer Pfanzenzuechtung der Martin - Luther - Universitaet Halle - Wittenberg Hohenthurm b. Halle/S., Germany (DDR) Much work has been done on the variability, genetics, and chemical nature of baking quality in the bread wheats. But there are not so many investigations concerning with the single components of quality and their variability in the possible contributors to hexaploid wheats. It is supposed that the introgression of Ae. squarrosa has raised the protein and accordingly the gluten content of the common wheat. One can suppose that the quality of the existing bread wheats is primary due either to the combination of contributors with different quality components or has originated by mutation on the tetraploid or hexaploid level. As part of a more comprehensive program we have carried out some investigations on the variability of baking quality factors in the following species : T. boeoticum, T. monococcum, Ae. speltoides (as the possible contributor of genome B), and Ae. squarrosa. The investigations were extended to the following characters, mainly used here for hexaploid wheats : Protein content of air-dried material (after Kjeldahl method), gluten quality (Testzahl by Schrotgaermethode after Pelshenke, and Quellzahl after Berliner & Koopmann), and wet gluten content. The judgement of baking quality by these indirect methods has revealed a sufficient agreement with standard- and microbaking tests in the hexaploid wheats. The results are summarized in table 1 listed below. We used for control the hexaploid wheat variety "Hadmerslebener Qualitas" with good quality under our conditions. In general our results confirm the findings of other workers that there is a close correlation between protein and gluten content. But there are considerable differences in gluten resp. protein content between the species. The high gluten contents especially of the two Aegilops species agree very well with the findings of YAMASHITA et al. (1956). In spite of the low number of strains in T. boeoticum there seem to be considerable differences in gluten resp. protein content between the two diploid wheats. The intraspecific variability of these two charactets mentioned being the least in T. boeoticum and much higher in T. monococcum. Nevertheless all strains investigated exceeded the control variety to a considerable amount. The evaluation of gluten quality showed some differences depending on the method used. There are no differences in mean values for the species, when Testzahlindex is applied, The variability of this character seems to be low with the exception of Ae. squarrosa. Gluten quality measured by Quellzahlen yielded lower values in general. The variability is however about the same. While there is a good agreement of Testzahlen between the control variety and the four species investigated, the use of Quellzahlen seems doubtful in our experiments. |