Genetic diversity of Seriphium plumosum - a grassland encroacher plant in South Africa

Abstract

ABSTRACT Seriphium plumosum, a grassland encroacher, has decreased the grazing capacity of grasslands in South Africa. The extensive spread of S. plumosum in South Africa requires a need to better understand its genetic characteristics. This study assessed the genetic diversity of five populations of S. plumosum using RAPD (random amplified polymorphic DNA) to understand the relationship between the genetics and the invasiveness of the species. Plant material was obtained from five different localities in the South-Eastern Free-State province (Frankfort, Parys, Senekal, Thaba Nchu, Zastron). DNA was extracted according to the CTAB protocol. Twenty-nine RAPD primers from Operon Technologies were used in polymerase chain reaction (PCR) technique to generate banding profiles of the samples. A total of 1095 bands amplified from all the populations produced between 52% to 70% polymorphism. Nei’s diversity indices for the populations ranged from 0.17 to 0.23. The Shannon’s information index (Ho ) varied between 0.21 to 0.30. The polymorphic percentage and the Ho index indicated that a high level of genetic diversity existed within S. plumosum. This variation may be one of the reasons for its success as an encroacher, as it enabled it to adapt and survive in changing environments. However, other factors may also enable the success of this invader.