FABI congratulates Aquillah Kanzi who successfully defended his PhD thesis at his oral examination on 11 July, a day after presenting his prestige seminar. His PhD study, titled “Comparative genomics of Chrysoporthe species” was supervised by Dr. Albe van der Merwe, Prof. Brenda Wingfield and Prof. Emma Steenkamp. On his oral examinational panel were Prof. Richard Hamelin of the Department of Forests and Conservation Sciences at the University of British Columbia, Dr. Barbara Robbertse of National Center for Biotechnology Information and Dr. Magriet van der Nest of the Department of Genetics at the University of Pretoria.

The aim of his study was to provide insight regarding the mating systems and evolution of Chrysoporthe species, which are economically important fungal pathogens that cause canker diseases on Eucalyptus species and indigenous tree species such as Syzygium. The study contributes to a better understanding of the biology of Chrysoporthe species.

Whole genome sequences of Chrysoporthe austroafricana, C. cubensis and C. deuterocubensis showed similarities in genome size, gene content and nucleotide composition. Further interrogation of these genomes identified variable mating-type loci that infer heterothallism in C. austroafricana and homothallism in C. cubensis and C. deuterocubensis. Using both mitochondrial and nuclear genes, Aquillah showed that hybridisation or introgressive hybridisation may have played a role in the evolution of Chrysoporthe species, and that these species might still be under lineage sorting, thus explaining the incongruent single gene phylogenies commonly inferred for in Chrysoporthe species.

Dr. van der Merwe congratulated Aquillah for a “fantastic thesis” and for not being afraid of tackling new challenges.