Neighboring plant influences on arbuscular mycorrhizal fungal community composition as assessed by T-RFLP analysis

• Published in: Plant and soil 2005-04, Vol.271 (1-2), p.83-90
• Main Authors: Mummey, D.L, Rillig, M.C, Holben, W.E
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Animal and plant ecology; Animal, plant and microbial ecology; Arbuscular mycorrhizas; Biochemistry and biology; Biological and medical sciences; Centaurea maculosa; Centaurea stoebe subsp. micranthos; Chemical properties; Chemical, physicochemical, biochemical and biological properties; Colonization; Community; Community composition; Dactylis glomerata; ecological succession; Forbs; Fundamental and applied biological sciences. Psychology; Fungi; Grasses; interspecific competition; Invasive plants; invasive species; microbial colonization; Microbiology; Mycorrhizal fungi; Nutrient status; Ordination; Parasitic plants. Weeds; Physicochemical properties; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Phytopathology. Animal pests. Plant and forest protection; Plant communities; Plant roots; Plant species; Plants; Polymerase chain reaction; Restriction fragment length polymorphism; root systems; Roots; Soil; Soil ecology; Soil fungi; Soil science; Spatial distribution; Species diversity; Symbionts; vesicular arbuscular mycorrhizae; Weeds
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-004-2066-6

Controls on root colonization by arbuscular mycorrhizal fungi (AMF) include host nutrient status, identity of symbionts and soil physico-chemical properties. Here we show, in the field, that the subset of the AMF community colonizing the roots of a common grass species, Dactylis glomerata, was strongly controlled by neighboring roots of a different plant species, Centaurea maculosa, an invasive forb, thus adding a biological spatial component to controls on root colonization. Using an AMF-specific, 18s rDNA-based terminal restriction fragment length polymorphism (T-RFLP) analysis method, significant differences were found between AMF community fingerprints of samples derived from roots of grasses with (GCm) and without (G0) neighboring C. maculosa. There were also significant differences between samples derived from C. maculosa roots (Cmac) and both GCm and G0 roots. Sample ordination indicated three generally distinct groups consisting of Cmac, Gcm and G0, with GCm samples being of intermediate distance between G0 and Cmac. Our results indicate that, with the presence of C. maculosa, AMF communities of D. glomerata shift to reflect community composition associated with C. maculosa roots. These results highlight the importance of complex spatial distributions of AMF communities at the scale of a root system. An additional dimension to our study is that C. maculosa is an aggressively invasive plant in the intermountain West. Viewed in this light, these results suggest that pervasive influences of this plant on AMF communities, specifically in roots of its competitors, may represent a mechanism contributing to its invasive success. However, further work is clearly required to determine the extent to which AMF genotypic alteration by neighboring plants influences competitive relationships.