Exploring the Origin and Genetic Diversity of the Giant Reed, Arundo donax in South Africa

Abstract

The giant reed,Arundo donaxis one of the worst invasive alien species globally, including South Africa, where it invades riparian areas across the country. Biological control is being considered to address the invasive potential and negative impacts of the weed. This study investigated the phylogeography ofA. donaxto guide the biological control program. To determine plant haplotype and genetic diversity, three regions of the chloroplast were sequenced and three microsatellite markers were analyzed in 40 samples from across the plant’s distribution in South Africa. It was determined that all populations ofA. donaxin South Africa were haplotype M1, which is the most widely distributed haplotype worldwide, believed to originate from the Indus Valley, Asia. In addition, no genetic diversity was found, indicating that all theA. donaxpopulations in South Africa are essentially one clone. The results indicate that suitable biological control agents are likely to be found in the ancient native range of haplotype M1. This research has contributed to the global understanding of the phylogeography ofA. donaxand will guide the biological control program in South Africa.