Characterization of <i>Pyrenophora tritici-repentis, Parastagonospora nodorum </i>and <i>Parastagonospora pseudonodorum </i>populations based on the presence of effector genes in the Tambov Oblast territory

Abstract

The aim of the research is to characterise the populations of Pyrenophora tritici-repentis, Parastagonospora nodorum and Parastagonospora pseudonodorum in the territory of the Tambov region based on the presence/absence of the Tox1, Tox3, ToxA and ToxB effector genes using their associated molecular markers. Infectious samples were obtained in 2022 from the leaves of spring and winter wheat. The infectious site is located in the northeastern part of the Central Black Soil region. The predecessor is represented by the pure steam. The species of P. nodorum and P. pseudonodorum were observed on spring wheat cultivars in the end of their vegetation period. The fungus of P. tritici-repentis affected the cultivars of both winter and spring wheat. Using molecular markers, the genes encoding NEs were identified in 68 P. tritici-repentis isolates obtained from 19 winter wheat cultivars, 100 P. nodorum isolates, taken from 10 spring wheat cultivars, and 70 P. pseudonodorum isolates, provided by 7 spring wheat cultivars. Among the P. nodorum isolates studied, there were both single genes Tox1, Tox3, and ToxA, as well as combinations of two genes in one genotype. The presence of the ToxA gene was not found in the genotype of P. pseudonodorum isolates. Fungal isolates with genotypes carrying Tox1 and/or Tox3 have been identified. The ToxB gene was not found in the examined population of P. tritici-repentis, while ToxA was widely represented. The occurrence of genes in the P. nodorum population was as follows: ToxA, 30%; Tox1, 20%; Tox3, 30%; in the population of P. pseudonodorum it was: Tox1 - 57.1%, Tox3 - 30 %; in the population of P. tritici-repentis the ratio was represented by the following figures: ToxA - 76.5%. P. tritici-repentis, P. nodorum, and P. pseudonodorum strains, characterized by the presence of effector genes, will be used to create artificial infectious backgrounds to identify sources and donors of leaf spot resistance.