In the frame of the Woody Weeds project, PhD student Maria Loreto studies species identity, presence of hybrids and the population genetic differentiation of founder plantation and invasive populations of Prosopis species, both in Kenya and Ethiopia, using microsatellite DNA markers. This is important information for understanding the invasion process and may affect management of the aggressive invader in Eastern Africa.
Measures of different plant traits are taken to understand how plants from invasive populations differ from the original plantations.
First results reveal that P. juliflora is the dominant invasive species in Kenya and Ethiopia and that the invasive populations consist of tetraploid individuals (have four copies of each chromosome) with low genetic differentiation. These are important findings, since polyploid individuals may be better invaders due to higher survival rates and fitness, and better able to adapt to new environmental conditions. More homogeneous populations indicate high dispersal potential, probably promoted by the movement of livestock (ungulates disperse seeds by ingesting its fruit), which have been indicated as an effective dispersal vector of Prosopis between populations and over long distance. Under this, effort should be focused on prevent animal use or movement through infested areas or create barriers to the movement of livestock into non-infested areas.