Tan Spot ( Pyrenophora tritici-repentis ) of Wheat: A Minireview

Abstract

Tan spot is a globally distributed disease caused by the necrotrophic fungus Pyrenophora tritici-repentis . It infects both durum and common wheat, leading to significant yield losses under conditions conducive to disease development. The fungus has a wide host range among grass species and can survive on alternative hosts, crop debris, and infected seeds. Management of tan spot involves several practices, including burning or burying crop debris from previous seasons, rotating crops with non-cereal species, and using non-infected seeds. While several fungicides are available for tan spot control, their use can be costly and raise environmental concerns. Although some common wheat varieties show limited resistance, very few durum wheat genotypes exhibit this trait. Efforts to breed for tan spot resistance have been both scant and largely unsuccessful. The lack of an effective differential set for identifying races of P. tritici-repentis from durum wheat, along with insufficient understanding of the host-pathogen interaction, has hindered breeding efforts and delayed the development of resistant varieties. This plant health case offers an overview of P. tritici-repentis , including its life cycle and genetic diversity. It also discusses the historical development and opportunities for improving the race classification system, along with the achievements and challenges associated with tan spot management. Information © The Authors 2024