Genetic variation among Southern African cultivated peanut (Arachis hypogaea L.) genotypes as revealed by AFLP analysis

Abstract

The amplified fragment length polymorphism (AFLP) technique, employing two different rare cutters, EcoRI and MluI in combination with the frequent cutter MseI, was used to assess genetic diversity and relationships among 21 closely related cultivated Southern African peanut genotypes. A dendrogram was constructed using Jaccard's coefficient and the UPGMA clustering method. Low levels of polymorphism (on average 2.78%) were detected. Results indicated that both EcoRI/MseI and MluI/MseIAFLP enzyme combinations efficiently detected polymorphism within closely related cultivated peanut, although the EcoRI/MseI enzyme combination detected more fragments per primer combination (on average 67.8) as opposed to29.7 by the MluI/MseI enzyme combination. All 21 genotypes could be uniquely distinguished from each other with a minimum of three MluI/MseI primer combinations. Genetic data correlated well with known species and pedigree data, dividing the 21 genotypes into two main groups corresponding to the two subspecies of Arachis hypogaea namely fastigiata and hypogaea. Divisions within the two main groups correlated with botanical types and pedigree data. This is the first report where MluI/MseI primer combinations were used on cultivated peanut and also the first successful detection of polymorphisms between closely related cultivated peanut genotypes worldwide.