Selection for increased variability of seed protein and lysine contents in wheat

Two projects within the Seibersdorf Laboratory programme for increased seed protein and lysine contents in wheat are described. The first experiment was started in 1971 with Svenno wheat. Selections for an increased protein content, measured by the modified Udy procedure developed at Seibersdorf, have yielded populations deviating from the unselected control means. However, due to large variation in the control population, the selection responses after mutagen treatment did not exceed that in the control. In the second experiment with line Mex 22A and initiated in 1973 it was possible to increase the variability in mutagenized populations when compared with selected control populations. Selections based upon DBC protein and % N have resulted in increased protein content in the selected populations and lines. Attempts to select for increased lysine content of seed protein based upon DBC value or upon ratios of DBC/N, DBC/proline or N/proline have not so far been successful. Further attempts are being based upon video-densitometry assays of lysine as a proportion of total amino acids. (author)