Ms Mashudu Nxumalo
Microbiology and Plant Pathology
My research focuses on characterization and biogeography of rhizobia associated with legumes in the Cape Florstic Region (CFR). Rhizobia are genetically diverse and physiologically heterogeneous group of bacteria that are capable to nodulate legumes and fix nitrogen. This has ecological and agricultural importance.
The CFR is located at the southwestern tip of the African continent. The CFR is the smallest among the other five floral kingdoms of the world, but unique with its richness in diversity of species. The region has therefore been a hub for much plant scientific research as many researchers continue to be fascinated by the rich diversity. Legumes in the CFR are currently comprised of about 760 species, in 37 genera (seven genera are endemic) belonging to 18 tribes. Most of these legumes are in symbiotic association with rhizobia that nodulate and fix nitrogen in nutrient poor soils. The legume species in the CFR occur in distinct populations in varying habitats ranging from water seeps, river valleys, and mountain slopes covering different soil types. However it is not known whether the rhizobia associated with the legumes also form distinct populations in the varying habitats and there is no mention of plant microbial associations contributing to the plant distribution pattern.
My research entails identification, studying the evolutionary origin(s) and determine distribution of the nodulation pattern diversity (biogeography) in the varying habitats of two legume species, Lebeckia and Virgilia. This also includes finding out what factors play a role in the distribution of the rhizobia in relation to their host distribution.