Racial status of Orobanche cumana Wallr. in some countries other the world

Abstract

Abstract The study represents a review of the evolution of the parasitic plant Orobanche cumana Wallr. and current racial status in some sunflower cultivating countries. Identification of racial status of broomrape populations belonging to eight sunflower cultivating countries from Europe and Asia (Republic of Moldova, Romania, Bulgaria, Ukraine, Spain, Turkey, Serbia and China) revealed the presence of high virulent races G and H in the majority of countries, except Serbia, where accessions belonging to race E or less virulent than E were found. The most virulent race H was identified particularly in the Black Sea area (Romania, Ukraine and Turkey). Additionally, the emergence of new biotypes characterized by high virulence, overcoming the resistance genes to race H was observed in some areas of the Republic of Moldova, Romania and Turkey, which signifies the importance of periodic evaluations of racial status for the prevention of occurrence and dissemination of new races. Analyzing the occurrence chronology of broomrape races in different countries we conclude that by the mid-1990s, the state of play was relatively stable, the most aggressive race being E. After this period the process of O. cumana development and appearance of new more aggressive and virulent biotypes became faster, which may be explained by the intensification of sunflower breeding activities and, respectively by the selection pressure exerted on the parasite by new resistant hybrids.