The role of molecular ecology in an invaded South Africa and its importance for biocontrol using Tamarix as a case study

The role of molecular ecology in an invaded South Africa and its importance for biocontrol using Tamarix as a case study
Samalesu G. MAYONDE1, Glynis V. Cron1, Kelsey Glennon1, Marcus J. Byrne1,2
1School of Animal Plant and Environmental Sciences, University of the Witwatersrand, Private Bag X3
2Centre for Invasion Biology

 The use of molecular techniques in invasion biology is regarded by many as a fairly new approach. Current research uses genetic tools to better understand the histories, processes and effects of plant invasions which are critical to improving control success of these organisms. The role of this presentation is to provide an overview of how molecular techniques can be used to aid the management of alien invasive plants in South Africa. Tamarix species are known to have considerable morphological and ecological similarities which generate confusion when trying to identify them morphologically. Genetic analyses identified three species of Tamarix in South Africa with hybrids between all the parental species, removing the taxonomic confusion. Further analyses examining the intraspecific genetic diversity showed that 64% of Tamarix invasion is hybrids. Hybridization and introgression are known to be a significant component of Tamarix invasion as they increased genetic diversity, generated potential successful novel genotypes and can swamp the native T. usneoides gene pool, all of which can be a limiting factor to biocontrol, i.e., the hybridization in Knapweed. Molecular techniques have many applications in biocontrol and invasion biology. These include instances where source populations of pompom weed in South Africa were identified; tracking of introduction routes of pompom weed and Tamarix in South Africa; and elucidating mechanisms of local spread and adaptations. All of these can be invaluable for host specificity testing of potential agents for biocontrol of existing invasive plants.