Selection indices for quality evaluation in wheat breeding

From multilocation trials involving 125 cultivars of wheat of mainly French and European origin four tests - protein content, Pelshenke, modified Zeleny and the mixograph - were used to establish six selection indices. Three of these indices - IW1, IW2 and IW3 - were calculated in order to evaluate the genetic potentiality of the lines for dough strength as given by the Chopin alveograph. The indices IV1, IV2 and IV3 were established to evaluate loaf volume as measured by the French bread-making standard. A quality index IQ was calculated from the allelic effects of the high-molecular-weight (HMW) subunits of glutenin from 195 cultivars assessed by the Chopin alveograph and the Pelshenke test. Comparison of the relative efficiency of each of the six indices to the individual tests revealed the superiority of the indices over one or several technological parameters. The six selection indices and the quality index were compared using 30 very diverse F4 lines. Their ability to retain the good quality lines is discussed in particular.