Variability of the cleistothecia and distribution of Erysiphe magnifica (U. Braun) U. Braun & S. Takam. on Magnolia L. plants in O.V. Fomin Botanical garden

The variability of morphometrie characteristics of the cleistothecia of fungus Erysiphe magnifica on different species from the genus Magnolia L. has been considered. It has been shown that on the different nutrient plants are forming the micropopulations of fungus which are notable for the cleistothecia parameters frequency of distribution and variability of their indices. The invasion activity of fungus increases in сonditions of the Botanical garden, it dеmages 8 species of plants of the genus Magnolia.