Résumé
Differences in milling behavior among hard-type common wheat (Triticum aestivum) cultivars are well known to millers. Among them, the French cultivar Soissons, which contains the Pinb-Dld allelic form of the puroindoline b gene, is particularly distinguished for its high milling value. Near-isogenic lines (NILs) differing by the allelic forms of the puroindoline b gene, Pinb-Dld or Pinly-D1b (one of the most frequent alleles found in the European wheat population), were constructed. Grain characteristics obtained after wheat cultivation in distinct environmental conditions were compared between NILs and the cultivar Soissons, as was their fractionation behavior. Results showed that NILs containing the Pinb-D1d allele displayed lower values of grain hardness and vitreousness than did the corresponding lines containing the Pinb-D1b allelic form under the same cultivation conditions. Both genetic background and environmental conditions appeared to affect grain texture. Measured single-kernel characterization system hardness index values of the samples under study were found to be correlated with the vitreousness values. Studies of the milling behavior helped to point out that grain vitreousness is an important factor acting on endosperm breakage ability, whatever the genetic background of the wheat. Our results also demonstrated that, at similar levels of vitreousness, the endosperm of Soissons could more easily be reduced than that of other wheat lines.