Ayçiçeği mildiyösü etmeni Plasmopara halstedii (Farl.) Berl. & de Toni’nin Türkiye’deki ırklarının tespiti ve bazı ticari ayçiçeği çeşitlerinin bu ırklara karşı reaksiyonlarının belirlenmesi

Abstract

Downy mildew of sunflower caused by Plasmopara halstedii, is the most important disease of sunflower throughout the world including Turkey. Within the scope of the study, surveys were performed in Tekirdağ, Edirne, Kırklareli, Ankara, Bursa, Samsun, Tokat and Adana provinces where sunflower is widely grown in the period of 2009-2015. During the surveys, sixty-five P. halstedii isolates were obtained and purified. Using the race differentials set, nine races of the pathogen (100, 102, 110, 300, 500, 502, 510, 702 and 712) were determined. All races determined are first records for Turkey, whereas the races 102, 510 and 110 are the first record for the world. Almost 71% percent of the races were belonged to race 100. The reactions of 19 commercial sunflower cultivars against P. halstedii were determined by using isolates representing different races of downy mildew. None of the commercial sunflower cultivars showed resistance against all the races of P. halstedii at the same time. Among varieties tested LG5580 was found to be resistant to four races, whereas Sanay MR, Sanbro MR, LG540HO, and Sanbro varieties were found to be 3,3,2 and 1 races, respectively.