The transition of a breeding system from outcrossing to selfing has been considered to be a widespread evolutionary trend in flowering plants, allowing species to colonize new habitats after long-distance dispersal. Moreover, Darwin realized that autonomous self-pollination could be an adaptation to reproduction if pollinator services were lost or extremely unpredictable. In a recent study published in AoB PLANTS, Xiong et al. tested a hypothesis that the persistence of Himalayan mayapple (Podophyllum hexandrum), an early spring flowering herb in the Himalayan region, is attributable to the transition from self-incompatibility to self-compatibility i.e. the capacity for selfing in an unpredictable pollination environment. To clarify whether automatic self-pollination is achieved by movement of the pistil as suggested in a previous study, they measured incline angles of the pistil and observed flower movement during anthesis. They found that automatic self-pollination was facilitated by petals closing and stamens moving simultaneously to contact the stigma. A scarcity of pollinators may have driven the shift to delayed selfing in Podophyllum hexandrum.
Pollinator scarcity drives the shift to delayed selfing in Himalayan mayapple Podophyllum hexandrum (Berberidaceae)
The transition of a breeding system from outcrossing to selfing has been considered to be a widespread evolutionary trend in flowering plants.