Journal
ANNALS OF BOTANY
Volume 119, Issue 8, Pages 1319-1331Publisher
OXFORD UNIV PRESS
DOI: 10.1093/aob/mcx028
Keywords
Acacia; invasive; mutualism; nitrogen fixation effectiveness; rhizobia; root nodule; symbiotic promiscuity
Categories
Funding
- National Research Foundation [93591, 81825, 76912]
- Oppenheimer Memorial Trust
- Australian Research Council [DP150103017]
Ask authors/readers for more resources
Background and Aims The ability to fix atmospheric nitrogen is thought to play an important role in the invasion success of legumes. Interactions between legumes and nitrogen-fixing bacteria (rhizobia) span a continuum of specialization, and promiscuous legumes are thought to have higher chances of forming effective symbioses in novel ranges. Using Australian Acacia species in South Africa, it was hypothesized that widespread and highly invasive species will be more generalist in their rhizobial symbiotic requirements and more effective in fixing atmospheric nitrogen compared with localized and less invasive species. Methods To test these hypotheses, eight localized and 11 widespread acacias were examined using next-generation sequencing data for the nodulation gene, nodC, to compare the identity, species richness, diversity and compositional similarity of rhizobia associated with these acacias. Stable isotope analysis was also used to determine levels of nitrogen obtained from the atmosphere via symbiotic nitrogen fixation. Key Results No differences were found in richness, diversity and community composition between localized and widespread acacias. Similarly, widespread and localized acacias did not differ in their ability to fix atmospheric nitrogen. However, for some species by site comparisons, significant differences in delta 15N isotopic signatures were found, indicating differential symbiotic effectiveness between these species at specific localities. Conclusions Overall, the results support recent findings that root nodule rhizobial diversity and community composition do not differ between acacias that vary in their invasiveness. Differential invasiveness of acacias in South Africa is probably linked to attributes such as differences in propagule pressure, reasons for (e.g. forestry vs. ornamental) and extent of, plantings in the country.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available