A A C C   2 0 0 0   A n n u a l   M e e t i n g

Due to insufficient quantity of early generation samples in wheat breeding programs, hard winter wheat experimental lines (F4-6) are evaluated by a mixograph rather than by experimental breadmaking. The three primary data obtained from a mixogram are optimum mix time (MT), water absorption (WA), and mixing tolerance (TOL) of a given flour. We have made a critical review of mixograph parameters in relation to breadmaking (pup straight dough procedure) parameters using 1706 experimental lines. There were highly significant correlations between mixograph and bake parameters for MT (r=0.848) and for WA (r=0.526). Bake WA can be estimated better from mixo WA if flour protein content and TOL scores are given (r=0.619). Mixograph TOL scores were linearly correlated with bake MT (r=0.697), bread crumb grain scores (r=0.271), LV potential (r=0.241), and bake WA (r=0.186, P<0.0001). Mixograph TOL scores ranged from 0 (unsatisfactory) to 5 (outstanding) with 4 being satisfactory. Bake parameters were compared between samples with different TOL scores: those (N=23) having 0 TOL showed significantly shortest MT, the lowest WA, the smallest LV and LV potential and the worst crumb grain scores, followed by those (N=120) having 1 TOL and those (N=225) having 2 TOL. In conclusion, it is justfiable to discard lines with low TOL scores from breeding lines, and a mixograph is a suitable instrument for early generation screening purposes.