A study of the genetic polymorphism of

Plasmopara viticola oomycete is a seasonal pathogen that causes one of the most harmful diseases of the grapevine – downy mildew. The study of the biodiversity of Plasmopara viticola in various zones of viticulture has fundamental goals, as well as practical ones, as it is important for understanding the epidemiological cycle of P. viticola and for refining disease prediction models. The purpose of the work is to study the genetic diversity of P. viticola in the vineyards of the Krasnodar Territory, including on the grape varieties with different levels of resistance to downy mildew. The study was conducted on pathogens samples collected on grape plants of varieties with varying degrees of resistance to downy mildew. The collection of material was carried out in May-August 2019 in various zones of the Krasnodar Territory. 48 samples of P. viticola were analyzed. The DNA markers BER, ISA, CES, GOB, PV91, PV137, PV143, PV144 recommended for studying the genetic diversity of P. viticola were used. The work was performed by PCR. The amplification products were evaluated by the method of fragment analysis. DNA-marker GOB identified 37 alleles of different sizes, PV144 – 20, CES – 10, BER – 3, PV91 – 3, PV137 – 2, ISA – 1, PV143 – 1. It was shown that P. viticola populations are variable on different varieties and in different geographical areas. This study was conducted in the Krasnodar Territory for the first time