Analysis of genetic relationships of pearl millet (Pennisetum glaucum L.) landraces from Zimbabwe, using microsatellites

Abstract

Pearl millet (Pennisetum glaucum L.) is the fifth most important cereal crop in Zimbabwe, with great potential in food security and biofuels. However, the rich pearl millet genetic diversity is either partially characterised or poorly documented resulting in their limited use in breeding programs. In this study the authors report an analysis of genetic relationships of pearl millet landraces collected from two districts of Zimbabwe, Nyanga north and Tsholotsho based on nine microsatellite primers and indigenous farmer given names. Analysis was done by PAGE stained with ethidium bromide. Simple matching coefficients were compared and the genetic relationships between genotypes were clarified on dendrograms by unweighted pair-group averages (UPGMA). Two polymorphic primers (PSMP2008 and PSMP2013) were able to detect some level of polymorphism at DNA level clustering the landraces into four major clusters joined at 64% similarity level. Sixteen accessions from Nyanga were identical to those from Tsholotsho. Forteen accessions from Nyanga and 18 Tsholotsho were identical to at least one genotype from the same district. Despite the same local names, genotypes were scattered throughout the clusters suggesting either poor discrimination by the primers or marked genetic differences. The Simpson Index of diversity were almost the same at 0.690 and 0.700 for Nyanga and Tsholotsho respectively. In conclusion, the results show the potential of microsatellites in studying diversity in pearl miller and show market duplication of the germplasm both in genetic relationships and local names. However, the study provides a strong background for further analysis of the germplasm