[Simulation of quantitative characters by genes with biochemically definable action : V. Investigations of the methods of measurement].

At measuring the anthocyanin content of the flowers of defined genotypes of the stock, Matthiola incana, in preceding investigations a comparatively high variability of the measured values within the lines was observed. The investigations on the genetics of the quantitative character "anthocyanin content" are based on these measurements. Therefore it is important to examine whether or not an insufficient isogenisation of the genetic background of the parental lines or errors in the measuring technique are partly responsible for the high variability. The elimination of recognizable sources of error should lead back the variation within a line mainly to the interaction between genotype and environment.The results show that differences in the genetic background are unlikely. On the contrary there are the following sources of error in the hitherto applied technique: 1. Unequal sampling with respect to the developmental stage of the flowers and of the single petals within double flowers. 2. Unequal patterns of extraction dependent on the quantity and quality of the anthocyanins. 3. Errors in pipetting in connection with the dilution of extracts. An improved technique of sampling and processing is proposed.