Loss of buzz pollination results in chronic pollen limitation in an enantiostylous plant

• DOI: 10.1016/j.sajb.2024.06.019
• Publication Date: 2024-07-03T15:50:22Z
• Authors: Babu Ram Paudel; Alice L.M. Fairnie; Sam McCarren; Bruce Anderson; Nicola Illing; Spencer C.H. Barrett
• Keywords: Marketing buzz; Hand-pollination

Plants with specialised pollination systems may be susceptible to reduced fertility if they are incapable of autonomous self-pollination and visited infrequently by pollinators capable promoting effective cross-pollination. Here, we investigate this question examining the reproductive ecology Cape endemic Cyanella alba subsp. flavescens (Tecophilaeaceae), which has mirror-image flowers (enantiostyly) dimorphic anthers (heteranthery). These traits usually associated buzz mediated bees that extract pollen from poricidal through vibration. We quantified insect visitation in three populations over two years vicinity Biedouw Valley, Western Cape, South Africa determine whether plants were buzz-pollinating bees. also recorded visits other co-flowering species at each site constructed a network on visitation. conducted controlled hand pollinations bagging experiments self-compatible self-pollination, compared natural levels fruit seed set those obtained cross-pollination evaluate evidence for limitation fertility. Despite 74 h field observations, only actively visiting flowers, although observed community. The most frequent visitors C. opportunistic pollen-consuming beetles no direct population exhibited chronic set. Controlled demonstrated moderately self-sterile self-pollination. Although was high following few seeds evident within developing fruit. Observations pollen-tube growth self- revealed abundant tubes base styles both treatments. Thus, self-sterility probably results late-acting ovarian self-incompatibility, possibly abortion due inbreeding depression. discuss possible causes scarce consider its ecological evolutionary consequences.