Bryological and Lichenological Section/ABLS
True, Nicole , Aanenson, Rachel , Fuselier, Linda .
Effects of Ultraviolet Radiation on Asexual Propagules of Marchantia polymorpha.
THE depletion of the ozone layer, clear-cutting in riparian vegetation zones, and other types of habitat loss have contributed to an increase in ambient ultraviolet (UV) radiation reaching historically sheltered habitats. Increased UV exposure can be directly harmful to terrestrial plants and may also have far-reaching effects in plant populations. Liverworts, considered the earliest land plants, may harbor insights into how plants react to increased ambient UV radiation and the impacts of these effects on clonal plant propagation. Populations of Marchantia polymorpha, a thallose liverwort that inhabits shaded riparian zones along permanent lotic systems, relies primarily on asexual reproduction for population maintenance and colonization of open substrate. We exposed gemmae of Marchantia polymorpha to enhanced ultraviolet radiation in a controlled experiment. Gemmae were grown on agar in 96-well plates in a growth chamber under UV-transparent and UV-filtering plastic covers in a randomized block design. The experimental plants were exposed to 16 hours of UV-enhanced radiation over two days, after which gemmae growth, rhizoid production and pigment expression were measured. Gemmae exposed to UV radiation had lower growth rates, and shorter and fewer rhizoids than gemmae shielded from UV radiation. Pigment expression is currently being analyzed. Slower growth and reduced rhizoid production likely translate into reduced colonization potential for gemmae exposed to UV radiation. Our results suggest that asexual propagules important for population maintenance and colonization may suffer direct effects of increased ambient UV-radiation. These detrimental effects may result in population losses in historically sheltered habitats.
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1 - Minnesota State University Moorhead, Biosciences, 1104 7th Ave. S., Moorhead, Minnesota, 56563, USA
Presentation Type: Poster:Posters for Sections
Location: Auditorium/Bell Memorial Union
Date: Tuesday, August 1st, 2006
Time: 12:30 PM