[The pigment content of induced mutants of Pisum sativum as basis for a new method of color specification and its correlation with plastid size].

Several methods for characterizing the color of pigment mutants can be found in the literature. Either verbal descriptions or comparisons with a color catalogue are used. These methods are subjective. Furthermore, the usual classifications of the pigment mutants as viridis, chlorina or xantha are not clearly defined. An attempt was therefore made to characterize the color of different Pisum mutants through a mathematically calculable "Farbwert" (Color value) obtained by spectrophotometric pigment analysis. This value takes into account the quantity as well as the quality of the pigment. However, the color also depends on secondary factors, e.g. the size and the amount of plastids, their arrangement in the mesophyll, the extent of intercellular space, the waxy layer of the epidermis, and possible hairiness. The correlation between plastid size and pigment content was investigated.