Boron fertilization and the root morphology of shortleaf pine seedlings inoculated with Pisolithus tinctorius

Abstract

Benefits associated with ectomycorrhizal infection are well established. However, exploitation of this symbiosis has been hindered, in part, by the inability to obtain consistently high infection rates. Past research in our laboratory has identified a twofold increase in Pisolithus tinctorius [(Pers.) Coker and Couch] ectomycorrhizal infection of shortleaf pine (Pinus echinata Mill.) seedlings in response to boric acid fertilization. This response was accompanied by a decrease in root indole-3-acetic acid (IAA) content. Other research investigations have associated the physiological function of boron in plants with root growth. An experiment has been conducted to assess the root system morphology of shortleaf pine seedlings inoculated or noninoculated with P. tinctorius and fertilized with none or 25 ug/ml boric acid. Results suggest that boric acid fertilization may enhance lateral root branching and elongation of shortleaf pine seedlings inoculated with P. tinctorius. This response, attributed to interaction between ectomycorrhizal root IAA and boric acid, may have resulted in increased ectomycorrhizal colonization.

Citation

Sword, Mary Anne; Garrett, Harold E. 1991. Boron fertilization and the root morphology of shortleaf pine seedlings inoculated with Pisolithus tinctorius. In: Coleman, Sandra S.; Neary, Daniel G., comps. and eds. In: Proceedings of the sixth biennial southern silvicultural research conference; 1990 October 30-November 1; Memphis, TN. Gen. Tech. Rep. SE-70. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station: 52-63.