Leaf Spot Caused by spp. Is a New Disease of Grapevine.

In this study, we carried out large-scale leaf spot symptom observation on vineyards in the Krasnodar Krai of Russia and determined their distribution. The incidence and severity of leaf spot were higher on the Euro-American grapevine hybrids (Bianka, Levokumskij, Avgustin, Moldova, Pervenets Magaracha, Dunavski lazur). A total of 433 isolates that belonged to the genus were isolated from samples with leaf spot. Pathogenicity testing confirmed the ability of the representative isolates to cause necrosis on the grapevine. The isolates of sp. were typed by the loci of internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (), Alternaria allergen a1 (), β-tubulin (), and translation elongation factor (). Isolates from grapevine causing leaf spot were shown to cluster with isolates of (Fr.) Keissl. and E.G. Simmons species complex. Of the fungicides tested to inhibit growth, the most effective were mixtures, such as pyrimethanil and fluopyram, cyprodinil and fludioxonil, and those that included difenoconazole. The results of the study expand our knowledge of the biodiversity of sp. fungi and can be used to limit the spread of leaf spot of the grapevine.