The Breeding Systems of Three Cooccurring Legumes: Dillwynia hispida, Dillwynia uncinata and Pultenaea densifolia (Leguminosae, Papilionoideae)

Abstract

The breeding systems of Dillwynia hispida Lindley, D. uncinata (Turcz.) J. Black and Pultenaea densifolia F. Muell. were determined using glasshouse trials and field experiments. Each species is self-incompatible and thus relies on pollen vectors to effect seed-set. Calculations of pollen-ovule ratios are compatible with this conclusion. Increase in the age of pollen led to a decline in fruit-set, which was more pronounced in Dillwynia uncinata than D. hispida or P. densifolia. In this study, Pultenaea densifolia pollen was never more than 60% viable which may explain the extremely high pollen-ovule ratio of this species. In all three species, esterase production on stigmas implied that they were fully receptive by day 3 of flowering. Stigma morphologies were assessed by scanning electron microscopy and the results used to discuss their incompatibility mechanisms.