IN INOCULANTS Nodulaid - 17th International Nitrogen Fixation ...

17 th International Congress on Nitrogen Fixation
Fremantle, Western Australia
27 November – 1 December 2011
Session Details: Tuesday 29 November 2011
Concurrent Session 6 – Field Applications II
1100 - 1230
Authors: Lori Phillips 1 , Bernadette Carmody 2 , Sharon Fox 3 , Lambert Brau 3 , Graham O‟Hara,
David Pearce 2
Presentation Title:
1 Department of Primary Industries Victoria, Bundoora Vic 3083;
Lori.Phillips@dpi.vic.gov.au
2 Department of Primary Industries Victoria, Rutherglen Vic 3685
3 Murdoch University, School of Biological Sciences and Biotechnology, Murdoch,
Western Australia 6150
Presentation Time: 1100 – 1120
Comparative diversity of rhizosphere and endophytic microbial communities in
faba cropping systems
Effective nodulation by rhizobia does not occur in an ecological void. Numerous and diverse microbial
communities exist in the soil and develop in the rhizosphere and endosphere of the growing legume. These
communities may influence effective nodulation, plant growth, and disease suppression, and represent a
significant potential co-inoculant resource. The primary objective of this study was to examine the impacts of
plant cultivar and inoculation treatment on the diversity of plant-associated bacteria. Faba bean cv. Farah and
Nura were sown in a field trial in Rutherglen, Victoria. This site had not been cropped with legumes for over a
decade. Treatments included non-inoculated controls, standard peat inoculation, peat inoculation at half the
recommended rate, and co-inoculation with a Pseudomonas spp (potential plant growth promoting rhizobacteria).
This trial is ongoing, and performance measurements to date include nodulation, root biomass, and shoot
biomass. Plant cultivar and inoculation treatment effects on rhizosphere and endophytic microbial communities
were evaluated using terminal restriction fragment length polymorphism (T-RFLP). Archaeal, bacterial, and
fungal diversity were assessed. Inoculation type had no significant impact on either nodule number or plant
biomass measures. Non-inoculated faba plants were well nodulated by resident rhizobial populations that
persisted for more than a decade in the absence of a legume host. T-RFLP data is currently under analysis, and
will further our understanding of the ecological parameters which help or hinder symbiotic success.
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2011