Racial diversity of broomrape (orobanche cumana Wallr.) in the world

Orobanche cumana Wallr. – a root parasitic weed that causes immense damage to sunflower crop, is a polymorphic species characterized by the existence of a series of biotypes, called physiological races, which differ depending on their ability to parasitize a certain genotype of host plant. The co-evolution host-parasite, as a result of specific gene-for-gene interactions, and the pressure on the broomrape by the continuous introduction of resistant sunflower hybrids favors the periodic emergence of new races of the parasite, which overcome existing resistance genes. This paper gives an overview on the chronology of the evolution of broomrape races in different countries of the world and presents some current analyses on the racial status of O. cumana in a number of sunflower-growing countries, such as China, Turkey, Bulgaria, Serbia, Spain, Ukraine and Romania.