PARENT SESSION
Monday, August 7, 5:00-6:30 pm
Poster Session 2 - Invasive species
Exhibit Hall, Ballroom Level, Cook Convention Center

The biochemistry of germination inhibition in Aegilops triuncialis.

Dyer, Andy^*,1, Schoppell, Samantha¹, Walker, Steven ¹, Mack, Tiffany ¹, ¹ University of South Carolina Aiken, Aiken, SC

ABSTRACT- The ability of non-native species to invade new habitats is potentially correlated with seed germination strategies. Linking the strategies to specific mechanisms that enhance establishment remains a problem. Aegilops triuncialis is an invasive annual grass that exhibits two strong mechanisms that induce dormancy in the smaller seed of dimorphic seed pairs. One influence is a water-soluble chemical on the surfaces of maternal tissues of the spikelet and the other is related to the presence of the larger seed. The strength of both inhibitors varies across populations and across years and is independent of absolute seed size. In this study we used infrared spectroscopic techniques (FTIR) to analyze the spectra of the leachate extracted from the maternal tissues. We looked for correlations between vertical peaks or horizontal wavelength shifts and germination values for ten populations of A. triuncialis seed collected in 2004. The results indicated strong positive and negative correlations (r = 0.53-0.67) between these variables. We report on the functional groups of chemicals corresponding to the spectral variation of the leachate. This research is important in that a greater understanding of the plasticity of germination suppression is likely to be directly linked to both biotic and abiotic growing conditions. A better understanding of the factors influencing germination will improve our understanding of the mechanisms favoring plant invasions.

Key words: invasive species, grassland, annual grass