© 1987 Heron Publishing—Victoria, Canada
Carbon allocation, root exudation and mycorrhizal colonization of Pinus echinata seedlings grown under CO2 enrichment
Richard J. Norby (1), E. G. O’Neill (1), W. Gregory Hood (2) and R. J. Luxmoore (1)
1. Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6034, USA / 2. Department of Biological Sciences, Florida State University, Tallahassee, Florida 32306, USA / Received September 16, 1986
Summary
Increased exudation of carbon compounds from roots may provide a mechanism for enhancement of nutrient availability to plants
growing in a CO2-enriched atmosphere. Therefore, the effect of atmospheric CO2 concentration on carbon allocation and root exudation was investigated in Pinus echinata Mill. (shortleaf pine) seedlings. After 34 and 41 weeks, seedlings growing in 695 μl l–1 CO2 allocated proportionately more 14C-labeled photosynthate to fine roots than did seedlings growing in ambient air. This was associated with greater fine root
mass and mycorrhizal density in CO2-enriched plants after 34 weeks. Exudation of soluble, 14C-labeled compounds from roots also was greater in these plants at 34 weeks, but the effect of CO2 concentration on exudation did not persist at 41 weeks.
