8th INTERNATIONAL WHEAT CONFERENCE

Second problem that had to be solved for an efficient use of the Reomixer in our breeding
program was the selection of the most appropriate environment for selection. Using data
from yield trials performed with or without irrigation and with or without Nitrogen fertilizer,
we found that both Genotypes and Environments significantly influenced the variation
of most dough mixing parameters. Interactions between genotypes and fertilization
and between genotypes and water availability were significant for all parameters, being
especially large for parameters where average effects of N fertilization or water availability
were less significant (“peak height” and “initial slope” respectively).
There were large genetic differences in cultivar response to insufficient nitrogen. The negative
influence of insufficient Nitrogen availability on mixing parameters was smaller in
the genotypes with the best mixing parameters, and very strong in the weak gluten ones,
therefore offering hopes of selecting genotypes more tolerant to the effect of deficient N
nutrition on bread quality. For “organic agriculture”, where lower soil fertility cannot be
corrected by applying mineral fertilizers, exploiting the observed interactions of genotypes
with N fertilization and identification of genotypes that are less affected by a lower
N availability may become very important. Based on these results the decision was made
to analyze grain samples from plots grown both with and without Nitrogen fertilizer.
The Reomixer proved to be efficient in characterizing dough mixing properties of breeding
material, beginning from the grains harvested from head-rows, as only a small quantity
of flour is required for the test. It proved to be efficient I detecting variation in breadmaking
quality between closely related lines.
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