Simulation of quantitative characters by genes with biochemically definable action : II. The material.

An experimental system has been developed which allows the application of the mathematical model given in Part I of this series. It consists of all possible genotypic combinations of four loci involved in the modification of the anthocyanin molecule structure by oxydation, glycosidation, and acylation in the annual cruciferous garden plantMatthiola incana. These genes are varied against a background which is nearly isogenic with respect to the concentration of flower pigments. The qualitative actions and interactions of the genes and the composition and isogenisation of the genetic background are described.As a simulated quantitative character the total concentration of anthocyanins per petal fresh weight is used and measured in a reading spectrophotometer.The genetic structure of the material is a prerequisite for the analysis by means of the earlier given model, and the knowledge of the qualitative actions and interactions of the involved genes may be useful in the interpretation of the estimations of the parameters and possibly facilitate an improvement of the model.