Bridget Giffei
Project Description
"Post -Pollination Biology of Ruppia maritima"
Ruppia maritima is an aquatic angiosperm that grows in brackish estuarine and coastal waters on every continent except Antarctica. R. maritima exhibits water pollination, in which pollen grains are transported across the water surface in pollen rafts to receptive stigmas. The goal of this research was to characterize the progamic phase, the period of development from pollen germination to fertilization, in R. maritima. In order to determine the rate of pollen germination and pollen tube growth, immature flowers were field collected and kept in individual aquaria in a greenhouse until the stigmas became receptive. The flowers were then hand-pollinated and collected at intervals of 5-15 minutes after pollination. Carpels were stained and imaged using fluorescence microscopy. Pollen grains germinated within five minutes after pollination and fertilization was achieved within an hour after pollination. Pollen tubes were measured at each time point to determine the average rate of pollen tube growth. Rapid pollen germination and pollen tube growth rates in R. maritima are important for achieving reproductive success, as fertilization must occur before pollen grains are washed off of the stigma. We also confirmed that R. maritima can self-fertilize, thus improving its reproductive success. This study not only yields data regarding the progamic phase in R. maritima, but also provides insight into reproductive traits associated with successful water-pollination.
Ruppia maritima is an aquatic angiosperm that grows in brackish estuarine and coastal waters on every continent except Antarctica. R. maritima exhibits water pollination, in which pollen grains are transported across the water surface in pollen rafts to receptive stigmas. The goal of this research was to characterize the progamic phase, the period of development from pollen germination to fertilization, in R. maritima. In order to determine the rate of pollen germination and pollen tube growth, immature flowers were field collected and kept in individual aquaria in a greenhouse until the stigmas became receptive. The flowers were then hand-pollinated and collected at intervals of 5-15 minutes after pollination. Carpels were stained and imaged using fluorescence microscopy. Pollen grains germinated within five minutes after pollination and fertilization was achieved within an hour after pollination. Pollen tubes were measured at each time point to determine the average rate of pollen tube growth. Rapid pollen germination and pollen tube growth rates in R. maritima are important for achieving reproductive success, as fertilization must occur before pollen grains are washed off of the stigma. We also confirmed that R. maritima can self-fertilize, thus improving its reproductive success. This study not only yields data regarding the progamic phase in R. maritima, but also provides insight into reproductive traits associated with successful water-pollination.
Presentations
2016
Botany 2016 (abstract)
Nebraska Academy of Sciences
Creighton University Research Day
Creighton Biology Department Research Colloquium
Botany 2016 (abstract)
Nebraska Academy of Sciences
Creighton University Research Day
Creighton Biology Department Research Colloquium
Publications
Taylor, M.L. *B.L. Giffei, *C.L. Dang, *A.E. Wilden, *K. M. Altrichter, *E.C. Baker, *R. Nguyen, and *D.S Oki. Reproductive ecology and postpollination development in the hydrophilous monocot Ruppia maritima. American Journal of Botany 107: 689–699