Genome-based systematics of Bradyrhizobium and its species

Abstract

In this thesis entitled "Genome-based systematics of Bradyrhizobium and its species", the genus Bradyrhizobium from a genome-based perspective, focusing on the evolutionary relationships of Bradyrhizobium species and their functional diversity in terms of their lifestyle traits is investigated. This study therefore resulted in the opportunity to construct a robust taxonomic hierarchy based on evolutionary history using genome data. Using the robust taxonomic hierarchy as a foundation, complex lifestyle traits such as nodulation, nitrogen fixation and photosynthesis could be examined. Furthermore, comparative genomics also allowed us to explore how Bradyrhizobium species are related to each other by studying the overall architecture of their genomes. This thesis also resulted in the first three Bradyrhizobium species associated with legumes in South Africa. The research presented in this thesis therefore serves as a stepping stepping-stone into the initial investigation of the various lifestyle traits of Bradyrhizobium. This thesis has also resulted in three publications which have appeared in internationally recognised scientific journals.