Selection for seed set capacity uncorrelated with flower heteromorphism in Primula vulgaris Hudson

Within-line pollinations were used when measuring the seed set of plants from seven early generation inbred lines of Primula vulgaris. One high seed setting plant and one low seed setting one were selected from each line and the seed set was evaluated on the offspring from selfings and within-line pollinations of these plants. Regression of offspring on parents for seed set was studied. The slope was estimated to be 0.17 +/- 0.08, equivalent to an estimated heritability of around 34%. No significant differences in the slope of regression between the two reproduction methods (selfings or within-line pollinations) were detected. The realized improvement through one cycle of selection of high seed setting single plants in this early generation inbred material of P. vulgaris was 23.7%. Analysis of the seed set of within-line pollinated clones from late generation inbred lines of P. vulgaris revealed that only limited within-line variation remained after removal of the effects of the heteromorphic incompatibility system. It was concluded that selection of high seed setting single plants during early generations of inbreeding is efficient for improvement of seed set in future inbred lines of P. vulgaris to be used for hybrid seed production.