Abstract Detail

Reproductive Processes

Stewart, Kyle [1], Chang, Shumei [2].

Pollen size, pollinator visitation, and the fate of pollen grains during pollination.

One well recognized pattern in pollination is that the majority of the pollen grains produced by a plant never reach their intended destination – conspecific stigmas but are instead lost during the pollen transfer process.  The fate of pollen grains can directly affect a plant’s male component of fitness but it remains poorly understood what determines where, when, and how pollen grains are retained or become lost during pollen transfer.  Even less is known on whether pollen characteristics, such as grain size and pollen morphology, may influence the success in pollen transfer. These gaps in our knowledge have hindered our progress in understanding how natural selection may act on the gametophytic stage of flowering plants and its effects on individual fitness.  Using potted common morning glory plants, Ipomoea purpurea, with distinct pollen sizes and wall structures and bumblebee colonies maintained in a greenhouse, we investigated the fate of pollen grains both during and after a single bumblebee pollinator visiting a sequence of experimental flowers.  Data of pollen traits and pollen movement were collected to address the following questions.  1) In the pollination process, what are the proportions of pollen grains, produced by a plant, have the following 5 pre-identified fates? (i) Remaining on the anthers, (ii) Falling onto corolla, (iii) Reaching a receptive stigma, (iv) Remaining on a pollinator’s body, and (v) Getting lost to unidentifiable locations. 2) Do the pollen grains picked up by bumblebees that visit multiple flowers form corresponding layers on the bee’s body? If so, how does the layering affect pollen’s likelihood to reach a stigma? 3) Does the size and other grain characteristics influence the answers to questions 1 and 2?

1 - Department of Plant Biology, University of Georgia, Athens, Georgia, 30602, United States
2 - Department Of Plant Biology, 2502 Miller Plant Sciences Building, Athens, GA, 30602, United States

Keywords:
Pollen size
Pollen carryover
pollen grain fate
Bumblebee pollination
Ipomoea purpura.

Presentation Type: Oral Paper
Number:
Abstract ID:692
Candidate for Awards:None