Genetics of self-compatibility in a self-incompatible wild diploid potato species Solanum chacoense. 1. Detection of an S locus inhibitor (Sli) gene

Abstract

A self-compatible (SC) variant of a wild diploid potato species, Solanum chacoense, which is normally self-incompatible (SI), was investigated for the nature and genetics of self-compatibility. It was crossed with a SI cultivated diploid potato species, S. phureja. The F1 progeny segregated SC vs. SI. Diallel crosses were made among 15 F1's. Self-compatibility was tested in a selfed family of a parental SC variant and in sib-mated and selfed families of F1 progeny. All the data suggest that there is a single dominant gene (Sli) with sporophytic action inhibiting S gene expression in the pollen. Plants having a ‘Sli’ gene, produce pollen which is compatible to its own parent and plants with similar S genes. The ‘Sli’ gene has been maintained in a heterozygous condition through eight selfing generations (S8) implying that dominant homozygotes might be associated with lethality.