The identification of racial background of broomrape Orobanche cumana Wallr. from the sunflower fields in the Krasnodar and Stavropol regions, Orenburg area and Kazakhstan

The racial structure of 15 populations of broomrape Orobanche cumana Wallr. from the 8 districts of the Krasnodar region was identified. There was also identified the racial background of parasite in 5 populations from 4 districts of the Stavropol region and in single samples of seeds from the Sovetsky district in the Orenburg area of the Russian Federation and from the Shemonaikhinsky district in Kazakhstan. Among the studied populations of O. cumana from the Krasnodar and Stavropol regions, the most part is a mixture of biotypes with different virulence against the background of a prevailing race E. However, in these regions, as well as in the Orenburg area, there already are fields infested with broomrape seeds with the predominance of a highly virulent race G. The sample of seeds of O. cumana from the Shemonaikhinsky district of Kazakhstan consists mainly of low virulent race C but contains a small addition of highly virulent biotype G, supposedly of natural origin and not related to the “pressure” of sunflower breeding process.