Measurement of inbreeding depression in Rhododendron kaempferi: seed production, germination, juvenile survival, and growth

To understand the reproductive ecology of a plant species with both selfing and outcrossing systems, it is important to know how selfed individuals contribute maintenance population. Further, examination magnitude inbreeding depression after pollination essential for accurate measurement success. In this study, we investigated characteristics viable seeds seedlings Rhododendron kaempferi in region where bumblebee pollinator Bombus ardens are abundant. hand-pollination experiment, fruit set from self-pollination was 32%, significantly lower than that outcross-pollination (81%). The number per one sixth outcross-pollination. However, negatively correlated weight seed. addition, germination rate low when seed light. Although could germinate, 89% died within year. coefficient 1 year sowing very high (0.89). These results indicate R. shows extremely strong selection but maintains slight potential natural population central Japan.