Sporophytic incompatibility with 2 and 3 genes

Abstract

The percentage of reciprocal and non-reciprocal incompatible matings between different genotypes in a diallel matrix have been used to discriminate between different incompatibility systems. By using these parameters, a satisfactory fit has been made of diallel matings in Eruca sativa to a sporophytic system with three complementary genes. The parameters exclude a two gene system but a four gene system is not excluded. Any system with gametophytic control is excluded. The proportions of dominance and co-dominance in the ‘best fit’ theoretical families is 2/5 dominant and 3/5 co-dominant pairs. The co-dominance among allelic pairs is distributed approximately evenly between pollen and style. The establishment of a three gene sporophytic system opens up new possibilities for the genetical and biochemical control of incompatibility in plants.