Genetic variation in wild sorghum (Sorghum bicolor ssp verticilliflorum (L.) Moench) germplasm from Ethiopia assessed by random amplified polymorphicDNA (RAPD)

The extent and distribution of genetic variation in wild sorghum (Sorghum b icolor ssp. verticilliflorum (L.) Moench) collected from five different geo graphical regions in Ethiopia were analyzed using random amplified polymorp hic DNA (RAPD) markers for 93 individuals representing 11 populations. Nine decamer primers generated a total of 83 polymorphic bands with 8-12 bands per primer and a mean of 9 bands across the 93 individuals. The amount of g enetic variation among the populations ((H) over bar = 0.37) and among the geographical region ((H) over bar = 0.44) was low to moderate, despite the high degree of polymorphic bands per primer. Similarly, the mean genetic di stance (0.08) among populations as well as among regions of origin (0.04) o f the population was found to be low. The low genetic variation may be due to the reduced population size of the wild sorghum in Ethiopia because of h abitat change. Partitioning of the genetic variation into between and withi n the population as well as between and within the regions of origin reveal ed that 75% and 88% of the variation was found within the populations and w ithin the regions, respectively. Cluster analysis of genetic distance estim ates further confirmed low level of differentiation of wild sorghum populat ions both on population and regional bases. The implications of the results for genetic conservation purposes are discussed.