ASHS 2024 Conference

Self-fertility, the ability of a plant to set fruits with self-pollen, is an important commercial trait in many crops. Self-fertility has the potential to set fruits in the absence of pollinators and pollenisers. Most macadamia cultivars are self-infertile but a few exhibit degrees of self-fertility. The potential morphological factors underpinning variability in this trait have not been previously investigated in macadamia. Therefore, this study aimed to determine whether floral reproductive morphology differs among self-fertile and self-infertile cultivars. Pistil length (PL), stamen length (SmL) and stigma-anther distance (SAD) were measured from cultivars within a self-fertile and a self-infertile group for two flowering seasons. The analysed self-fertile cultivars were ‘HAES 741’, ‘HAES 791’, ‘A38’, ‘Q’, ‘K’ and ‘UQM40’, while the self-infertile cultivars were ‘HAES 344’, ‘A16’, ‘Daddow’, ‘D4’ and ‘A268’. There was no significant difference between years for any of the traits (P>0.05). However, significant differences were found between the self-fertile/self-infertile groups and among cultivars within groups for the three examined traits (P