Pollen gene flow in South Australian cherry (Prunus avium L.) orchards

Summary. Isozyme analysis of sweet cherry embryos from 3 different South Australian orchards has proven to be an invaluable diagnostic tool. It has shown that in comparison with almond orchards, pollen gene flow occurs over much greater distances. Furthermore, pollen genes are being donated by more than one polleniser cultivar. For example, Sam planted at Lenswood Horticultural Centre was pollinated by both Vista and Merton Glory Protective netting was used to exclude birds from the cherry orchard at Lenswood and only 0.003% of the apparent net pollen gene flow came from cultivars planted outside of the net to those within. The presence of bird netting discouraged the movement of honeybees. Cross-compatible pollen rather than self pollen contributed most to embryo formation in the self-fertile cultivar Stella. Seventy-one percent of embryos produced by Stella at Lenswood were as a result of outcrossing. This work has culminated in some important recommendations for the cherry industry. Namely that where bird exclosures are used bee hives and polleniser cultivars should be placed inside the netted area, and when planting self-fertile cultivars, such as Stella, polleniser cultivars should be included in the orchard plan.