RAPD VARIATION WITHIN AND BETWEEN NATURAL-POPULATIONS OF MORAMA [TYLOSEMA-ESCULENTUM (BURCHELL) SCHREIBER] IN SOUTHERN AFRICA

RAPD markers were used to investigate genetic variation in natural pop ulations of morama [Tylosema esculentum (Burchell) Schreiber]. This sp ecies is a wild, perennial, outbreeding legume indigenous to the Kalah ari Desert region of southern Africa. Morama seed has a high protein c ontent and has traditionally been an important wild source of food for the people of this region. It is considered to have great potential f or development as a new crop for the semi-arid tropics. investigation of genetic diversity is a prerequisite for the genetic improvement of any species and this is the first such investigation in morama. Consid erable RAPD variability was detected in each of the three morama popul ations sampled. Most of this variation (85%) occured within, rather th an between, populations in agreement with other studies involving outb reeding perennial species. This suggests that sufficient genetic varia tion for breeding purposes maybe found by sampling 30-40 plants from o nly one or two populations. There were significant differences in the frequency of RAPD loci between populations but no population-specific RAPD markers were found. Although there was no clear evidence of popul ation differentiation between the morama populations, more intensive s ampling may reveal details of within-population genetic structure in t hese populations. This analysis confirms the usefulness of RAPD marker s for investigation of genetic variation in natural populations and th e technique is fast and provides numerous polymorphic markers.