Microsatellite analysis of Pinus taeda L. in Zimbabwe

Deducing the origin of early 20th century introductions of Pinus taeda into Zimbabwe is possible given microsatellite markers and clear population dif ferentiation in ancestral U.S. populations. This study was designed to dete rmine whether P. taeda introductions into Zimbabwe came from one U.S. regio n or whether the present-day population is an admixture of introductions fr om east and west of the Mississippi River Valley. Principal components anal ysis, Cavalli-Sforza and Edwards' chord distances and presence of diagnosti c alleles each indicate that the Zimbabwe population is an admixture. There were five novel alleles in the Zimbabwe population not represented in the indigenous U.S. populations, possibly because of de novo mutation, introgre ssion with other introduced North American pines or sampling error.