University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Doctoral Thesis:
Michaela Prischl
(2011):
Effects of Transgenic Maize on Beneficial Plant-Microbe Interactions and Soil- Nitrogen-Cycling .
Doctoral Thesis - Institut für Bodenforschung (IBF),
BOKU-Universität für Bodenkultur,
pp 122.
UB BOKU
obvsg
- Abstract:
- The use of transgenic maize expressing Bacillus thuringiensis (Bt) insecticidal proteins means a decreased need for conventional, broad spectrum pesticides. To address concerns regarding the environmental safety of transgenic crops, I studied microbial groups performing important functions in the soil-plant-system in two different soils under transgenic maize (MON89034, MON88017, and MON88017xMON89034) as compared to the near isogenic line (DK315) and three additional conventional maize varieties. Seven hundred bacterial endophytes from maize roots were isolated and analyzed regarding plant growth promoting functions including 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase and indole-3-acetic acid (IAA) production. Isolates produced ACC deaminase irrespective of the soil and plant cultivar; and IAA producers were affected by the soil but not the plant cultivar. Terminal restriction fragment length polymorphism (T-RFLP)-based profiling resulted in the differentiation of the maize root endophytic communities according to soil type and plant cultivar but not with respect to Bt- versus non-Bt varieties. The soil mineral nitrogen (N) content, potentially mineralizable N pools and the abundances of ammonia oxidizing and denitrifying microbial communities were affected by the different soils and by the different sampling times throughout the three year-study involving horse bean rotational cropping. However, soils under distinct maize cultivars did not differ regarding N-parameters or nitrifier and denitrifier abundances, and thereby also no effect of Bt expression could be evidenced.
- Betreuer:
- 1. Berater:
- 2. Berater: