An Introduction to Hermaphroditism in Kiwifruit (Actinidia deliciosa A. Chev.)

Hermaphroditism in flowering plants refers to the presence of both male and female sex organs in a single flower. Actinidia, the kiwifruit is approximately 20 to 26 million years old, known widely for its dioecious nature. Androgyny which is also known as hermaphroditism has also been found to exist in its male inconstant type. Male parts of the flower in kiwifruit develop early during the third stage of (A)BCE model of floral development, whereas, the degeneration of these parts (pollens) in female plants occurs during later stages owing to programmed cell death. After exploring the sex-linked segment of the kiwifruit genome, the researchers have determined that the Y-encoded sex-determinant genes Shy Girl (SyGl) and Friendly Boy (FrBy) act independently as the suppressors of feminization and promoters of male factors, respectively. Non-expression of SyGl in males results in the formation of hermaphrodites; yet, masculine behaviour has been reported to develop in this fruit crop with the plunking of FrBy gene into the female plants. The study speculated that the manipulation of SyGl and/or FrBy can potentially change the dioecy of elite cultivars of kiwifruit to hermaphroditism. This would provide kiwifruit vines with high reproductive assurance, eliminating the need for pollinizers or pollinators. In the future, orchard productivity could be increased by planting only elite hermaphrodite vines, negating the need to plant any male vines that are fruitless. These findings have created new avenues for generating horticulturally important self-pollinating hermaphrodite vines, eliminating the need to waste orchard space on non-fruiting male varieties.