PARENT SESSION
Poster Session #25: Mycorrhizal Fungi and Root Processes.
Tuesday, August 6. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC

Mycorrhizal species differentially influence biomass and photosynthetic rates of Liriodendron tulipifera L. (tulip poplar) in the presence of aluminum .

Klugh, Katrina^*,1, Springer, Clint¹, Thomas, Richard¹, Cumming, Jonathan¹, ¹ West Virginia University, Morgantown, WV

ABSTRACT- Aluminum (Al) present in acidic soils is phytotoxic, exerting a myriad of detrimental effects on plant physiological processes. Mycorrhizal fungi may confer Al resistance to their plant hosts, and this benefit may differ among species of mycorrhizal fungi. The present study was designed to evaluate plant response to Al and determine if the response was dependent upon mycorrhizal symbiont. Liriodendron tulipifera seedlings were inoculated with one of four arbuscular mycorrhizal fungal species, Glomus clarum, Glomus claroideum, Paraglomus brasilianum, or Acaulospora morrowiae and grown in sand culture. Aluminum treatments of 0, 50, and 200 M were delivered in solution. After eight weeks of treatment, biomass and photosynthetic rates were measured. Aluminum significantly reduced biomass. A significant interaction of fungal species and Al treatment was evident: biomass of seedlings colonized by G. clarum remained high with elevated Al treatments, while that of seedlings colonized by other mycorrhizal species decreased. Photosynthetic rates in all seedlings were depressed at 200 M Al, while slightly stimulated at 50 M Al. Trends in the data suggest seedlings colonized by G. clarum had higher photosynthetic rates than any other fungal species studied. Mycorrrhizal fungi are known to alter plant nutrient and metal uptake. Since photosynthesis may reflect leaf levels of nitrogen, phosphorus, or other elements, the observed variation in photosynthesis may reflect differences in foliar nutrient levels resulting from colonization by different fungal species.

KEY WORDS: Mycorrhizae, Aluminum, Photosynthesis, Liriodendron tulipifera