South Africa is remarkably rich in legumes and their bacterial symbionts (also referred to as rhizobia), with which they contribute significantly to biological nitrogen-fixation. Rhizobial associations are crucial for legume establishment and general ecosystem health. In the case of non-native agricultural legumes, these symbiotic bacteria are relatively well-studied. In contrast very little is known about the identity and evolution of rhizobia associating with native legumes and their potential in agricultural settings.  From a biodiversity point of view, rhizobia may also facilitate invasion by non-native legumes such as Australian Acacia species, and/or encroachment by generalist native species such as Vachielia karroo. 

The overall goals of our research are to characterise and describe the rhizobia associated with both native and non-native legume species (including agricultural important legumes such as soybean). For this purpose, we employ standard microbiological procedures combined with genetics and genomics approaches to study the processes driving rhizobial evolution and to reconstruct their evolutionary histories. In this way, we endeavour to determine how rhizobial identity and genetics relate to legume host, geography and environmental factors, to ultimately shed light on the possible forces shaping the biogeography, ecology and agricultural application of these bacteria