Electrophoresis of leaf and seed proteins of Englerophytum natalense (fam. Sapotaceae)

Abstract

Englerophytum natalense is an indigenous South African tree, bearing edible fruits. In view of its potential for domestication, leaf and seed proteins were separated electrophoretically in order to investigate the existence and degree of variation within and between populations in respect of these proteins. This was part of a process to search for genetic markers, enabling desirable traits to be identified at an early stage in the lives of non-fruiting trees. Acid Polyacrylamide Gel Electrophoresis (A-PAGE) was performed, but yielded no results. Sodium Dodecyl Polyacrylamide Gel Electrophoresis (SDS-PAGE) was successful, both when using leaves of different ages, and when using seeds. A number of variables in the technique were investigated and compared, and optimum parameters are documented. The gels were analysed with the AlphaEaseTMv 3.3 computer package. The densitometric diagrams showed no variation within or between populations; suggesting that either the species is genetically very uniform, or that the proteins investigated do not constitute suitable markers for variation in this species.