Mycorrhizal Infection Reduces Shortterm Aluminum Uptake and Increases Root Cation Exchange Capacity of Highbush Blueberry Plants

Abstract

Aluminum (Al) uptake by and root cation exchange capacity (CEC) of mycorrhizal (M) and nonmycorrhizal (NM) blueberry (Vaccinium corymbosum L.) plants were studied. Root CEC was higher in M plants than in NM plants, but total and root Al contents were higher in NM plants. Leaf Al content was higher in NM than in M plants after 1 and 5 hours of exposure. The aurintriboxylic acid stain for Al indicated the presence of Al in the M symbiont. Despite a larger root system and higher root CEC, regression analysis indicated roots of M plants absorbed less Al in the first 5 hours, suggesting that Al sequestration in the M symbiont is responsible for reduced total Al uptake. Differences in dry matter partitioning between M and NM plants were also observed.