Fruit shape and reproductive self and cross compatibility for the performance of fruit set in an andromonoecious species: <Emphasis Type="Italic">Xanthoceras sorbifolium</Emphasis> Bunge

A replicated 6 × 6 complete diallel mating among six fruit shape types of Xanthoceras sorbifolium (yellowhorn), an andromonoecious plant known for its exceedingly low fruit and seed set, was conducted to investigate the species mating system. This mating design was implemented to investigate the relationship between fruit shape type and fruit yield, finding the most productive fruit shape-type matings, and explore maternal and paternal plants spatial arrangements for yield enhancement. The study confirmed the maternal inheritance of fruit shape type, open-pollination often associated with low fruit production, the presence of high inbreeding depression, and differential yield among fruit shape-type matings and directions and identified specific matings between fruit shape types with increased yield potential for the species’ commercial production. A high fruit yield planting spatial arrangement of parents is proposed and its pro et contra under open-pollinated production mode were discussed.