Phylogeny and systematics of white blister rusts (Albuginales): insights into true diversity

White blister rust (WBR) pathogens of the family Albuginaceae are globally distributed obligate biotrophic oomycetes infecting a wide range of wild and cultivated plants, including economically important crops. Traditionally classified within a single genus, Albugo, molecular phylogenetic studies have demonstrated that WBR pathogens comprise several deeply divergent lineages, including Albugo sensu stricto, Albugo sensu lato, Wilsoniana, Pustula, and additional intermediate lineages that may represent distinct genera. These lineages typically exhibit strong host specificity; however, within Albugo sensu stricto both specialist and generalist species may occur on the same host species, suggesting a complex evolutionary history. Recent evidence indicates that the diversity within Albuginaceae has been substantially underestimated. In particular, the Albugo candida species complex appears to represent an ongoing evolutionary radiation, with several genetically distinct lineages showing indications of reproductive isolation. Despite recent advances, white blister rust pathogens remain poorly explored across many ecological regions and host systems, and their evolutionary relationships are still incompletely resolved. This project therefore aims to conduct a comprehensive multigene phylogenetic study of Albuginaceae using nuclear (ITS, LSU) and mitochondrial (cox2) markers across diverse host families and geographically distinct regions, including Germany, Iran, Italy, and global herbarium collections. By integrating molecular phylogenetic analyses with morphological data, the project seeks to clarify species boundaries and establish a modern taxonomic framework for white blister rust pathogens.