A review of geographical distribution of marama bean [Tylosema esculentum (Bruchell) Schreiber] and genetic diversity in the Namibian germplasm

Abstract

Marama bean [Tylosema esculentum (Burchell) Schreiber] occurs naturally in the drier areas of Southern Africa, including Botswana and Namibia. The implementation of molecular breeding is important to advance the process of securing the world’s food supply. The development of molecular markers is vital for mapping important traits that can then be followed in subsequent breeding programs. This study assessed the distribution of marama bean in Namibia and isolated microsatellite regions for microsatellite primer design for the purpose of determining genetic diversity and construction of molecular genetic maps for marama. This will greatly enhance the process of domesticating marama bean, currently a wild plant that is still picked wild and unsustainably. The geographical distribution was geo-referenced using Geographic Positioning System (GPS) points and microsatellites were isolated from the germplasm using a modified FIASCO technique. The study revealed widespread, but patchy distribution of marama bean in Namibia. Five Marama bean microsatellite enriched libraries were created. The initial results provided vital information for the ongoing marama bean conservation function and improvement program.