REPRODUCTIVE BARRIERS IN TREE FRUIT CROPS AND NUTS

Reproductive barriers are important breeding concerns in many fruit and nut cultivars, where fruit set and nut filling require efficient and predictable fertilization.
The past decade has seen a rapid increase in our understanding of the molecular basis of incompatibility.
Gametophytic self-incompatibility is one of the best-understood and very widely distributed systems.
Based on the understanding of model systems, identification and breeding for incompatibility traits have rapidly progressed in important cultivars, particularly in the Rosaceae.
Recent results from the Brassicaceae provide the same type of molecular understanding for sporophytic self-incompatibility and can hopefully be applied in the near future.
New methodologies can now be added to traditional breeding methods to analyze and help select for desired traits including self-fertility, seedlessness, increased fruit-set, hermaphroditism, and reduction of dichogamy.