Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/24/2003
Publication Date: 11/2/2003
Citation: FANG, M., KREMER, R.J., MOTOVALLI, P. BACTERIAL COMMUNITIES IN RHIZOSPHERES OF TRANSGENIC CORN STUDIED BY DENATURING GRADIENT GEL ELECTROPHORESIS (DGGE) AND BIOLOG METABOLIC FINGERPRINTS. AGRONOMY ABSTRACTS. 2003. CD-ROM (UNPAGINATED). AMERICAN SOCIETY OF AGRONOMY. MADISON, WI.
Technical Abstract: Rhizosphere microbial communities of two transgenic corn (Zea mays) varieties (Bt and Roundup Ready) were analyzed and compared to communities of non-transgenic isolines in greenhouse and field studies. Two complementary methods (BIOLOG metabolic fingerprinting and DGGE) were used. In the greenhouse study, samples from silt loam, sandy loam and silty clay soils were collected before planting and at the ten-leaf growth stage. BIOLOG profiling showed that soil texture and time of sampling significantly influenced the diversity and structure of the microbial community. However, microbial communities of the two transgenic corn varieties could not be discriminated from the non-transgenic isolines. The DGGE patterns of the samples for each soil texture formed separate subclusters, which indicated an obvious difference in microbial communities. High similarity of DGGE patterns (greater than 85%) between transgenic and non-transgenic corn was observed in all three soil textures. In the field study, corn varieties were planted in a Mexico silt loam soil (fine, montmorillonitic, mesic Mollic Endoaqualf), and soil samples were collected on three occasions at the beginning, middle, and end of the growing season. Similar results from the field study based on BIOLOG and DGGE profiles further supported that corn varieties, regardless of genetic modification, did not significantly affect microbial community structure.