Sexually localized expression of pseudo-self compatibility (PSC) in Petunia X hybrida Hort. : 1. Pollen inactivation

A naturally occurring, 100% PSC Petunia X hybrida Hort. plant was found which had normal stylar function, but lacked S allele activity in the pollen. Preliminary characterization showed the phenotype to be identical to that of a pollen part mutant as described by Lewis (1949). Linkage test results, using a plant with the pollen-inactivation PSC factor as male parent, agreed with earlier observations that crossing over between S and the factor was rare. However, when the plant bearing the factor was used as female, apparent recombinants were recovered, although they were all of one class. Unequal gamete competition based on inter-line incongruity could explain the failure to recover recombinants from the male parent.