News
« back | more news »      
 

PENNISETUM SETACEUM RESEARCH TAKES C·I·B STUDENT TO NORTH AFRICA

Marguerite Blignaut, a PhD student within the Molecular Ecology Group embarked on what has become known as the “world tour” within the laboratory. The aim of the trip was to collect Pennisetum setaceum (fountain grass) samples from its native range in North Africa, and invasive ranges in Spain.

Fountain grass invades disturbed areas and roadside, and can spread rapidly through wind dispersal. It is drought-resistant, fire promoting and unpalatable to animals, and for these reasons it is classified as a Category 1 invasive species in South Africa. The grass offers an excellent model system for geneticists because of its supposed complete lack of genetic diversity, wide spread dispersal and consequent adaptation worldwide.

Marguerite’s PhD project aims to describe epigenetic variation and inheritance within and between P. setaceum. Previous research by Marguerite’s supervisor, Dr Jaco Le Roux, showed that global native and invasive populations of the grass are monoclonal (all individuals are genetically identical), even though they can differ in morphology, physiology and invasiveness. Marguerite’s research focuses on whether epigenetic processes within and among fountain grass populations give rise to different phenotypic responses, without requiring changes in the DNA code.

South African P. setaceum populations are classified as “moderately invasive” compared with the populations found in Hawaii and Spain. Findings from her research could significantly improve our understanding of the role of epigenetics in plant evolution, ploidy and possible adaptation when species are introduced into a new or changed environment.

Searching for P. setaceum in the foothills of the Atlas Mountains with Jbel Toubkal in the distance.

Marguerite set off during May to collect native P. setaceum populations from Egypt and Morocco, as well as highly invasive populations in Spain. With three weeks, three countries and many thousands of kilometers to travel, Marguerite started her journey in Egypt. The search for fountain grass required patient taxi drivers; a perfumery for English translations and directions, and many u-turns to locate GPS coordinates. Although many of the previously reported populations of fountain grass around Cairo do not exist anymore due to urban development, some populations were collected near and around Al-Geiza, and with the help of the taxi-driver sample collections went well.

Morocco was next on the list for collections. Even though coordinate data was lacking for P. setaceum, reports and descriptions of the grass near towns and within the south east of Morocco had been obtained from the Université Mohamed V-Agdal herbarium in Rabat. The first locality was near Jbel Toubkal, the highest point in North Africa. With a local guide from Asni, a small town in the foothills of Jbel Toubkal, and armed with photos of fountain grass, the search for fountain grass commenced, but with no success. Local Berbers still trek with camels across the Sahara to Timbukthu and they reported seeing P. setaceum in the fertile Drâa valley. The trip thus took a detour through the Drâa valley on the way to Erfoud, but still no fountain grass could be found. The grass couldn’t be found in any of the other reported regions, which meant that the return journey crossed the Middle Atlas Mountains towards the north-west of Morocco. Finally fountain grass was found just outside of Khemisset, Rabat and Casablanca. A total of 2600 km later, and beautiful landscapes that included deserts, valleys, oases and fertile farmland, the Moroccan leg of the trip ended in Tangier, and continued north towards Spain.

Marguerite collecting P. setaceum next to the Mediterranean highway close to Almeria.

Fountain grass is highly invasive in Spain, and although it was only introduced as recently as twenty years ago, it already occupies a wide range along the southern Andalucían region and eastern coast of Spain. Locality data was provided by collaborators from the University of Almeria, and samples were collected from Málaga, Granada and Almeria. The grass is found mainly next to roads in disturbed habitats, and the collected populations were found along the Mediterranean highway, that snakes along the eastern Spanish coastline all the way to Barcelona, and finally into France. The first stop was Málaga, a beautiful Mediterranean seaside town, followed by sampling in the foothills of the impressive snow-capped Sierra Nevada Mountains, Granada. A short visit to Almeria included sample collection and a visit to Capo de Gata, the largest terrestrial-maritime reserve in the Mediterranean Sea, and a UNESCO Biosphere Reserve. Due to the rapid spread of fountain grass along the coast, the grass may reach this reserve in as little as two years.