Root architectural tradeoffs for water and phosphorus acquisition in common bean (Phaseolus vulgaris L.).
(4608)
Authors:
M.D. Ho* - Penn State University J.C. Rosas - EAP/Zamorano, Honduras J.P. Lynch - Penn State University
Abstract:
Spatial deployment of the root system determines the ability of a plant to obtain heterogeneous soil resources. While root architectures that exploit topsoil resources efficiently are advantageous in low phosphorus (P) soils, this may result in reduced water acquisition, as water availability often increases with depth. Experiments were conducted in the greenhouse at University Park, PA and in the field at
Zamorano, Honduras to examine the implications of root shallowness for water and P acquisition. Parental and recombinant inbred (RI) lines of common bean with contrasting root architectures were grown under four treatments in the greenhouse and field: 1)adequate water and P; 2)water stress; 3)P stress; and 4)combined water and P stress. In the greenhouse, BAT477, which has shallow basal roots, but a relatively deep tap root, acquired more total P and outperformed both the shallow and the deep genotype in all treatments. The shallow genotype acquired more total P and outperformed the deep genotype in the P stress treatment, while the opposite occurred in the water stress treatment. Shallow genotypes performed slightly better than deep genotypes under the combined stress treatment. Similar results were obtained from the field using RI lines. These results support the hypothesis that there are tradeoffs between a given root architecture form and function. The importance of a dimorphic root system for the acquisition of heterogeneously distributed resources will be discussed.
Speaker Information: Melissa Ho, Penn State University, 102 Tyson Bldg, University Park, PA 16802; Phone: 814-863-6168; E-mail: [email protected]
Session Information: Tuesday, November 2, 2004, 8:25 AM-11:15 AM Presentation Start: 8:25 AM
Keywords: root architecture; tradeoffs; water; phosphorus
